Merge branch '28717-additional-metrics-review-branch' into 'master'

app/assets/javascripts/prometheus_metrics/constants.js

+export default {
+  EMPTY: 'empty',
+  LOADING: 'loading',
+  LIST: 'list',
+};

app/assets/javascripts/prometheus_metrics/index.js

+import PrometheusMetrics from './prometheus_metrics';
+
+$(() => {
+  const prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+  prometheusMetrics.loadActiveMetrics();
+});

app/assets/javascripts/prometheus_metrics/prometheus_metrics.js

+import PANEL_STATE from './constants';
+
+export default class PrometheusMetrics {
+  constructor(wrapperSelector) {
+    this.backOffRequestCounter = 0;
+
+    this.$wrapper = $(wrapperSelector);
+
+    this.$monitoredMetricsPanel = this.$wrapper.find('.js-panel-monitored-metrics');
+    this.$monitoredMetricsCount = this.$monitoredMetricsPanel.find('.js-monitored-count');
+    this.$monitoredMetricsLoading = this.$monitoredMetricsPanel.find('.js-loading-metrics');
+    this.$monitoredMetricsEmpty = this.$monitoredMetricsPanel.find('.js-empty-metrics');
+    this.$monitoredMetricsList = this.$monitoredMetricsPanel.find('.js-metrics-list');
+
+    this.$missingEnvVarPanel = this.$wrapper.find('.js-panel-missing-env-vars');
+    this.$panelToggle = this.$missingEnvVarPanel.find('.js-panel-toggle');
+    this.$missingEnvVarMetricCount = this.$missingEnvVarPanel.find('.js-env-var-count');
+    this.$missingEnvVarMetricsList = this.$missingEnvVarPanel.find('.js-missing-var-metrics-list');
+
+    this.activeMetricsEndpoint = this.$monitoredMetricsPanel.data('active-metrics');
+
+    this.$panelToggle.on('click', e => this.handlePanelToggle(e));
+  }
+
+  /* eslint-disable class-methods-use-this */
+  handlePanelToggle(e) {
+    const $toggleBtn = $(e.currentTarget);
+    const $currentPanelBody = $toggleBtn.closest('.panel').find('.panel-body');
+    $currentPanelBody.toggleClass('hidden');
+    if ($toggleBtn.hasClass('fa-caret-down')) {
+      $toggleBtn.removeClass('fa-caret-down').addClass('fa-caret-right');
+    } else {
+      $toggleBtn.removeClass('fa-caret-right').addClass('fa-caret-down');
+    }
+  }
+
+  showMonitoringMetricsPanelState(stateName) {
+    switch (stateName) {
+      case PANEL_STATE.LOADING:
+        this.$monitoredMetricsLoading.removeClass('hidden');
+        this.$monitoredMetricsEmpty.addClass('hidden');
+        this.$monitoredMetricsList.addClass('hidden');
+        break;
+      case PANEL_STATE.LIST:
+        this.$monitoredMetricsLoading.addClass('hidden');
+        this.$monitoredMetricsEmpty.addClass('hidden');
+        this.$monitoredMetricsList.removeClass('hidden');
+        break;
+      default:
+        this.$monitoredMetricsLoading.addClass('hidden');
+        this.$monitoredMetricsEmpty.removeClass('hidden');
+        this.$monitoredMetricsList.addClass('hidden');
+        break;
+    }
+  }
+
+  populateActiveMetrics(metrics) {
+    let totalMonitoredMetrics = 0;
+    let totalMissingEnvVarMetrics = 0;
+
+    metrics.forEach((metric) => {
+      this.$monitoredMetricsList.append(`<li>${metric.group}<span class="badge">${metric.active_metrics}</span></li>`);
+      totalMonitoredMetrics += metric.active_metrics;
+      if (metric.metrics_missing_requirements > 0) {
+        this.$missingEnvVarMetricsList.append(`<li>${metric.group}</li>`);
+        totalMissingEnvVarMetrics += 1;
+      }
+    });
+
+    this.$monitoredMetricsCount.text(totalMonitoredMetrics);
+    this.showMonitoringMetricsPanelState(PANEL_STATE.LIST);
+
+    if (totalMissingEnvVarMetrics > 0) {
+      this.$missingEnvVarPanel.removeClass('hidden');
+      this.$missingEnvVarPanel.find('.flash-container').off('click');
+      this.$missingEnvVarMetricCount.text(totalMissingEnvVarMetrics);
+    }
+  }
+
+  loadActiveMetrics() {
+    this.showMonitoringMetricsPanelState(PANEL_STATE.LOADING);
+    gl.utils.backOff((next, stop) => {
+      $.getJSON(this.activeMetricsEndpoint)
+        .done((res) => {
+          if (res && res.success) {
+            stop(res);
+          } else {
+            this.backOffRequestCounter = this.backOffRequestCounter += 1;
+            if (this.backOffRequestCounter < 3) {
+              next();
+            } else {
+              stop(res);
+            }
+          }
+        })
+        .fail(stop);
+    })
+    .then((res) => {
+      if (res && res.data && res.data.length) {
+        this.populateActiveMetrics(res.data);
+      } else {
+        this.showMonitoringMetricsPanelState(PANEL_STATE.EMPTY);
+      }
+    })
+    .catch(() => {
+      this.showMonitoringMetricsPanelState(PANEL_STATE.EMPTY);
+    });
+  }
+}

app/assets/stylesheets/pages/settings.scss

@@ -126,3 +126,66 @@
     margin-left: 5px;
   }
 }
+
+.prometheus-metrics-monitoring {
+  .panel {
+    .panel-toggle {
+      width: 14px;
+    }
+
+    .badge {
+      font-size: inherit;
+    }
+
+    .panel-heading .badge-count {
+      color: $white-light;
+      background: $common-gray-dark;
+    }
+
+    .panel-body {
+      padding: 0;
+    }
+
+    .flash-container {
+      margin-bottom: 0;
+      cursor: default;
+
+      .flash-notice {
+        border-radius: 0;
+      }
+    }
+  }
+
+  .loading-metrics,
+  .empty-metrics {
+    padding: 30px 10px;
+
+    p,
+    .btn {
+      margin-top: 10px;
+      margin-bottom: 0;
+    }
+  }
+
+  .loading-metrics .metrics-load-spinner {
+    color: $loading-color;
+  }
+
+  .metrics-list {
+    margin-bottom: 0;
+
+    li {
+      padding: $gl-padding;
+
+      .badge {
+        margin-left: 5px;
+        background: $badge-bg;
+      }
+    }
+
+    /* Ensure we don't add border if there's only single li */
+    li + li {
+      border-top: 1px solid $border-color;
+    }
+  }
+}

app/controllers/application_controller.rb

@@ -40,6 +40,10 @@ class ApplicationController < ActionController::Base
     render_404
   end
 
+  rescue_from(ActionController::UnknownFormat) do
+    render_404
+  end
+
   rescue_from Gitlab::Access::AccessDeniedError do |exception|
     render_403
   end

app/controllers/projects/deployments_controller.rb

@@ -22,6 +22,22 @@ class Projects::DeploymentsController < Projects::ApplicationController
     render_404
   end
 
+  def additional_metrics
+    return render_404 unless deployment.has_additional_metrics?
+
+    respond_to do |format|
+      format.json do
+        metrics = deployment.additional_metrics
+
+        if metrics.any?
+          render json: metrics
+        else
+          head :no_content
+        end
+      end
+    end
+  end
+
   private
 
   def deployment

app/controllers/projects/environments_controller.rb

@@ -129,6 +129,16 @@ class Projects::EnvironmentsController < Projects::ApplicationController
     end
   end
 
+  def additional_metrics
+    respond_to do |format|
+      format.json do
+        additional_metrics = environment.additional_metrics || {}
+
+        render json: additional_metrics, status: additional_metrics.any? ? :ok : :no_content
+      end
+    end
+  end
+
   private
 
   def verify_api_request!

app/controllers/projects/prometheus_controller.rb

+class Projects::PrometheusController < Projects::ApplicationController
+  before_action :authorize_read_project!
+  before_action :require_prometheus_metrics!
+
+  def active_metrics
+    respond_to do |format|
+      format.json do
+        matched_metrics = project.prometheus_service.matched_metrics || {}
+
+        if matched_metrics.any?
+          render json: matched_metrics
+        else
+          head :no_content
+        end
+      end
+    end
+  end
+
+  private
+
+  def require_prometheus_metrics!
+    render_404 unless project.prometheus_service.present?
+  end
+end

app/models/deployment.rb

@@ -114,6 +114,17 @@ class Deployment < ActiveRecord::Base
     project.monitoring_service.deployment_metrics(self)
   end
 
+  def has_additional_metrics?
+    project.prometheus_service.present?
+  end
+
+  def additional_metrics
+    return {} unless project.prometheus_service.present?
+
+    metrics = project.prometheus_service.additional_deployment_metrics(self)
+    metrics&.merge(deployment_time: created_at.to_i) || {}
+  end
+
   private
 
   def ref_path

app/models/environment.rb

@@ -157,6 +157,16 @@ class Environment < ActiveRecord::Base
     project.monitoring_service.environment_metrics(self) if has_metrics?
   end
 
+  def has_additional_metrics?
+    project.prometheus_service.present? && available? && last_deployment.present?
+  end
+
+  def additional_metrics
+    if has_additional_metrics?
+      project.prometheus_service.additional_environment_metrics(self)
+    end
+  end
+
   # An environment name is not necessarily suitable for use in URLs, DNS
   # or other third-party contexts, so provide a slugified version. A slug has
   # the following properties:

app/models/project_services/prometheus_service.rb

@@ -28,17 +28,6 @@ class PrometheusService < MonitoringService
     'Prometheus monitoring'
   end
 
-  def help
-    <<-MD.strip_heredoc
-      Retrieves the Kubernetes node metrics `container_cpu_usage_seconds_total`
-      and `container_memory_usage_bytes` from the configured Prometheus server.
-
-      If you are not using [Auto-Deploy](https://docs.gitlab.com/ee/ci/autodeploy/index.html)
-      or have set up your own Prometheus server, an `environment` label is required on each metric to
-      [identify the Environment](https://docs.gitlab.com/ce/user/project/integrations/prometheus.html#metrics-and-labels).
-    MD
-  end
-
   def self.to_param
     'prometheus'
   end
@@ -50,6 +39,7 @@ class PrometheusService < MonitoringService
         name: 'api_url',
         title: 'API URL',
         placeholder: 'Prometheus API Base URL, like http://prometheus.example.com/',
+        help: 'By default, Prometheus listens on ‘http://localhost:9090’. It’s not recommended to change the default address and port as this might affect or conflict with other services running on the GitLab server.',
         required: true
       }
     ]
@@ -65,23 +55,34 @@ class PrometheusService < MonitoringService
   end
 
   def environment_metrics(environment)
-    with_reactive_cache(Gitlab::Prometheus::Queries::EnvironmentQuery.name, environment.id, &:itself)
+    with_reactive_cache(Gitlab::Prometheus::Queries::EnvironmentQuery.name, environment.id, &method(:rename_data_to_metrics))
   end
 
   def deployment_metrics(deployment)
-    metrics = with_reactive_cache(Gitlab::Prometheus::Queries::DeploymentQuery.name, deployment.id, &:itself)
+    metrics = with_reactive_cache(Gitlab::Prometheus::Queries::DeploymentQuery.name, deployment.id, &method(:rename_data_to_metrics))
     metrics&.merge(deployment_time: created_at.to_i) || {}
   end
 
+  def additional_environment_metrics(environment)
+    with_reactive_cache(Gitlab::Prometheus::Queries::AdditionalMetricsEnvironmentQuery.name, environment.id, &:itself)
+  end
+
+  def additional_deployment_metrics(deployment)
+    with_reactive_cache(Gitlab::Prometheus::Queries::AdditionalMetricsDeploymentQuery.name, deployment.id, &:itself)
+  end
+
+  def matched_metrics
+    with_reactive_cache(Gitlab::Prometheus::Queries::MatchedMetricsQuery.name, &:itself)
+  end
+
   # Cache metrics for specific environment
   def calculate_reactive_cache(query_class_name, *args)
     return unless active? && project && !project.pending_delete?
 
-    metrics = Kernel.const_get(query_class_name).new(client).query(*args)
-
+    data = Kernel.const_get(query_class_name).new(client).query(*args)
     {
       success: true,
-      metrics: metrics,
+      data: data,
       last_update: Time.now.utc
     }
   rescue Gitlab::PrometheusError => err
@@ -91,4 +92,11 @@ class PrometheusService < MonitoringService
   def client
     @prometheus ||= Gitlab::PrometheusClient.new(api_url: api_url)
   end
+
+  private
+
+  def rename_data_to_metrics(metrics)
+    metrics[:metrics] = metrics.delete :data
+    metrics
+  end
 end

app/views/projects/services/_form.html.haml

@@ -23,3 +23,7 @@
             - disabled_title = @service.disabled_title
 
         = link_to 'Cancel', namespace_project_settings_integrations_path(@project.namespace, @project), class: 'btn btn-cancel'
+
+- if lookup_context.template_exists?('show', "projects/services/#{@service.to_param}", true)
+  %hr
+  = render "projects/services/#{@service.to_param}/show"

app/views/projects/services/prometheus/_show.html.haml

+- content_for :page_specific_javascripts do
+  = webpack_bundle_tag('prometheus_metrics')
+
+.row.prepend-top-default.append-bottom-default.prometheus-metrics-monitoring.js-prometheus-metrics-monitoring
+  .col-lg-3
+    %h4.prepend-top-0
+      Metrics
+    %p
+      Metrics are automatically configured and monitored
+      based on a library of metrics from popular exporters.
+      = link_to 'More information', '#'
+
+  .col-lg-9
+    .panel.panel-default.js-panel-monitored-metrics{ data: { "active-metrics" => "#{namespace_project_prometheus_active_metrics_path(@project.namespace, @project, :json)}" } }
+      .panel-heading
+        %h3.panel-title
+          Monitored
+          %span.badge.js-monitored-count 0
+      .panel-body
+        .loading-metrics.text-center.js-loading-metrics
+          = icon('spinner spin 3x', class: 'metrics-load-spinner')
+          %p Finding and configuring metrics...
+        .empty-metrics.text-center.hidden.js-empty-metrics
+          = custom_icon('icon_empty_metrics')
+          %p No metrics are being monitored. To start monitoring, deploy to an environment.
+          = link_to project_environments_path(@project), title: 'View environments', class: 'btn btn-success' do
+            View environments
+        %ul.list-unstyled.metrics-list.hidden.js-metrics-list
+
+    .panel.panel-default.hidden.js-panel-missing-env-vars
+      .panel-heading
+        %h3.panel-title
+          = icon('caret-right lg fw', class: 'panel-toggle js-panel-toggle', 'aria-label' => 'Toggle panel')
+          Missing environment variable
+          %span.badge.js-env-var-count 0
+      .panel-body.hidden
+        .flash-container
+          .flash-notice
+            .flash-text
+              To set up automatic monitoring, add the environment variable
+              %code
+                $CI_ENVIRONMENT_SLUG
+              to exporter’s queries.
+              = link_to 'More information', '#'
+        %ul.list-unstyled.metrics-list.js-missing-var-metrics-list

app/views/shared/icons/_icon_empty_metrics.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="64" height="64" viewBox="0 0 64 64">
+  <g fill="#E5E5E5">
+    <path d="M32 64C30.8954305 64 30 63.1045695 30 62 30 60.8954305 30.8954305 60 32 60 33.8894444 60 35.7536611 59.8131396 37.574335 59.4454933 38.6570511 59.2268618 39.7120017 59.9273408 39.9306331 61.0100569 40.1492646 62.0927729 39.4487856 63.1477235 38.3660695 63.366355 36.285133 63.7865558 34.1557023 64 32 64zM49.2301062 58.9696428C51.0302775 57.8173242 52.7114504 56.4871355 54.247711 55.0008916 55.0415758 54.232873 55.0625283 52.9667164 54.2945097 52.1728516 53.5264912 51.3789869 52.2603346 51.3580344 51.4664698 52.1260529 50.1212672 53.4274592 48.6493395 54.5920875 47.0736141 55.6007347 46.1433158 56.1962335 45.8719072 57.4331365 46.4674061 58.3634348 47.0629049 59.2937331 48.2998079 59.5651416 49.2301062 58.9696428zM61.0426034 45.4531856C61.9412068 43.5163476 62.6441937 41.4911051 63.1388045 39.4034279 63.393449 38.3286117 62.7285685 37.2508708 61.6537523 36.9962262 60.5789361 36.7415816 59.5011952 37.4064621 59.2465506 38.4812784 58.8141946 40.3061875 58.1997219 42.0764286 57.4141077 43.7697311 56.9492346 44.7717126 57.3846469 45.9608331 58.3866284 46.4257062 59.3886098 46.8905793 60.5777303 46.455167 61.0426034 45.4531856zM63.7270657 27.8034151C63.4476841 25.6718707 62.9558906 23.5863203 62.2616468 21.5714028 61.9018246 20.527084 60.7635435 19.9721898 59.7192246 20.3320119 58.6749058 20.6918341 58.1200116 21.8301152 58.4798337 22.874434 59.0867105 24.6357842 59.5166381 26.45898 59.760988 28.3232492 59.9045362 29.4184513 60.9087418 30.1899192 62.0039439 30.046371 63.099146 29.9028228 63.8706139 28.8986173 63.7270657 27.8034151zM56.4699838 11.3781121C55.0919588 9.74451505 53.5537382 8.25140603 51.8798083 6.92273835 51.0146495 6.23602588 49.7566092 6.38068523 49.0698968 7.24584403 48.3831843 8.11100284 48.5278436 9.36904308 49.3930024 10.0557555 50.8587525 11.2191822 52.2058153 12.5267396 53.4125204 13.9572433 54.1247279 14.8015385 55.3865225 14.9086168 56.2308177 14.1964094 57.0751129 13.484202 57.1821912 12.2224073 56.4699838 11.3781121zM41.481294 1.42849704C39.4470333.798260231 37.3474846.371987025 35.2067823.158824109 34.1076485.0493765922 33.1278998.851675811 33.0184523 1.95080957 32.9090048 3.04994333 33.711304 4.02969203 34.8104377 4.13913955 36.6833634 4.32563829 38.5191483 4.69835932 40.297557 5.24933028 41.3526509 5.57621023 42.4729622 4.98587613 42.7998421 3.93078217 43.1267221 2.8756882 42.536388 1.75537699 41.481294 1.42849704zM23.6558195 1.0993008C21.5852929 1.6571259 19.5822296 2.42161363 17.6728876 3.37914679 16.6855233 3.874309 16.2865147 5.07613416 16.7816769 6.06349841 17.2768392 7.05086266 18.4786643 7.44987125 19.4660286 6.95470905 21.1354949 6.11747332 22.8864813 5.44919307 24.6963667 4.96158787 25.7629079 4.67424869 26.3945759 3.57671185 26.1072367 2.51017072 25.8198975 1.44362959 24.7223606.811961615 23.6558195 1.0993008zM8.36290105 10.4291871C6.92120358 12.00815 5.63985273 13.7275139 4.53998784 15.5610549 3.97179016 16.5082746 4.27904822 17.7367631 5.22626792 18.3049608 6.17348763 18.8731585 7.40197615 18.5659004 7.97017383 17.6186807 8.9327668 16.0139803 10.054503 14.5087932 11.3168098 13.126301 12.0615972 12.3106016 12.0041117 11.0455771 11.1884123 10.3007897 10.372713 9.55600224 9.10768848 9.61348772 8.36290105 10.4291871zM.450120287 26.6230259C.151304663 28.3883054 0 30.1850053 0 32 0 32.2974081.00406268322 32.594367.0121750297 32.8908218.0423897377 33.994978.96197903 34.8655796 2.0661352 34.8353649 3.17029137 34.8051502 4.04089294 33.8855609 4.01067824 32.7814047 4.00356366 32.521412 4 32.2609289 4 32 4 30.4089462 4.13249902 28.8355581 4.39401589 27.2906242 4.57836807 26.2015475 3.84494393 25.1692294 2.75586724 24.9848772 1.66679054 24.800525.634472466 25.5339492.450120287 26.6230259zM2.45830096 44.3202494C3.28286321 46.2952494 4.30407075 48.1806071 5.50459135 49.9494734 6.124886 50.8634254 7.36863868 51.1014818 8.28259072 50.4811871 9.19654276 49.8608925 9.43459912 48.6171398 8.81430448 47.7031878 7.76386025 46.1554464 6.87058107 44.5062706 6.14951581 42.7791677 5.72395784 41.7598668 4.55266835 41.2785432 3.53336751 41.7041011 2.51406668 42.1296591 2.03274299 43.3009486 2.45830096 44.3202494zM13.73374 58.2776222C15.4883094 59.4994144 17.3614388 60.5433005 19.3262717 61.39161 20.3403619 61.8294398 21.5173756 61.3622885 21.9552054 60.3481983 22.3930351 59.3341082 21.9258838 58.1570945 20.9117937 57.7192647 19.1934726 56.9773858 17.5548741 56.0642026 16.0195384 54.9950736 15.1130877 54.3638678 13.8665707 54.5869979 13.2353649 55.4934487 12.6041591 56.3998995 12.8272892 57.6464164 13.73374 58.2776222zM30.6955071 63.9738646C29.5918263 63.9295649 28.7330282 62.9989428 28.7773279 61.895262 28.8216276 60.7915812 29.7522497 59.9327832 30.8559305 59.9770829 31.2344492 59.9922759 31.6140624 59.9999282 31.9946308 59.9999995 33.0992003 60.0002065 33.994463 60.8958047 33.994256 62.0003742 33.9940491 63.1049437 33.0984508 64.0002064 31.9938814 63.9999994 31.5600677 63.9999181 31.1272192 63.9911927 30.6955071 63.9738646zM30.1721098 44.2840559C30.7941711 46.023825 33.2407935 46.0619159 33.9167124 44.3423547L38.9452693 31.5495297 41.1315797 35.2685507C41.4908522 35.8796908 42.1468005 36.2549751 42.8557214 36.2549751L51.1106965 36.2549751C52.215266 36.2549751 53.1106965 35.3595446 53.1106965 34.2549751 53.1106965 33.1504056 52.215266 32.2549751 51.1106965 32.2549751L43.9999712 32.2549751 40.3112064 25.9802055C39.465988 24.5424477 37.3358287 24.7099356 36.7257006 26.2621229L32.1439734 37.9181973 26.2115967 21.3266406C25.5807315 19.562249 23.0875908 19.5563214 22.4483429 21.3176933L18.4775633 32.2587065 13 32.2587065C11.8954305 32.2587065 11 33.154137 11 34.2587065 11 35.363276 11.8954305 36.2587065 13 36.2587065L19.8793532 36.2587065C20.720826 36.2587065 21.4722973 35.732004 21.7593685 34.9410132L24.314328 27.9011249 30.1721098 44.2840559z"/>
+  </g>
+</svg>

changelogs/unreleased/28717-support-additional-prometheus-metrics.yml

+---
+title: Additional Prometheus metrics support
+merge_request: 11712
+author:

config/prometheus/additional_metrics.yml

+- group: Kubernetes
+  priority: 1
+  metrics:
+  - title: "Memory usage"
+    y_label: "Values"
+    required_metrics:
+      - container_memory_usage_bytes
+    weight: 1
+    queries:
+    - query_range: 'avg(container_memory_usage_bytes{%{environment_filter}}) / 2^20'
+      label: Container memory
+      unit: MiB
+  - title: "Current memory usage"
+    required_metrics:
+     - container_memory_usage_bytes
+    weight: 1
+    queries:
+    - query: 'avg(container_memory_usage_bytes{%{environment_filter}}) / 2^20'
+      display_empty: false
+      unit: MiB
+  - title: "CPU usage"
+    required_metrics:
+     - container_cpu_usage_seconds_total
+    weight: 1
+    queries:
+    - query_range: 'avg(rate(container_cpu_usage_seconds_total{%{environment_filter}}[2m])) * 100'
+  - title: "Current CPU usage"
+    required_metrics:
+     - container_cpu_usage_seconds_total
+    weight: 1
+    queries:
+    - query: 'avg(rate(container_cpu_usage_seconds_total{%{environment_filter}}[2m])) * 100'

config/routes/project.rb

@@ -73,6 +73,10 @@ constraints(ProjectUrlConstrainer.new) do
 
       resource :mattermost, only: [:new, :create]
 
+      namespace :prometheus do
+        get :active_metrics
+      end
+
       resources :deploy_keys, constraints: { id: /\d+/ }, only: [:index, :new, :create, :edit, :update] do
         member do
           put :enable
@@ -153,6 +157,7 @@ constraints(ProjectUrlConstrainer.new) do
           post :stop
           get :terminal
           get :metrics
+          get :additional_metrics
           get '/terminal.ws/authorize', to: 'environments#terminal_websocket_authorize', constraints: { format: nil }
         end
 
@@ -163,6 +168,7 @@ constraints(ProjectUrlConstrainer.new) do
         resources :deployments, only: [:index] do
           member do
             get :metrics
+            get :additional_metrics
           end
         end
       end

config/webpack.config.js

@@ -55,6 +55,7 @@ var config = {
     pipelines:            './pipelines/pipelines_bundle.js',
     pipelines_details:     './pipelines/pipeline_details_bundle.js',
     profile:              './profile/profile_bundle.js',
+    prometheus_metrics:   './prometheus_metrics',
     protected_branches:   './protected_branches/protected_branches_bundle.js',
     protected_tags:       './protected_tags',
     sidebar:              './sidebar/sidebar_bundle.js',

lib/gitlab/prometheus/additional_metrics_parser.rb

+module Gitlab
+  module Prometheus
+    module AdditionalMetricsParser
+      extend self
+
+      def load_groups_from_yaml
+        additional_metrics_raw.map(&method(:group_from_entry))
+      end
+
+      private
+
+      def validate!(obj)
+        raise ParsingError.new(obj.errors.full_messages.join('\n')) unless obj.valid?
+      end
+
+      def group_from_entry(entry)
+        entry[:name] = entry.delete(:group)
+        entry[:metrics]&.map! do |entry|
+          Metric.new(entry).tap(&method(:validate!))
+        end
+
+        MetricGroup.new(entry).tap(&method(:validate!))
+      end
+
+      def additional_metrics_raw
+        load_yaml_file&.map(&:deep_symbolize_keys).freeze
+      end
+
+      def load_yaml_file
+        @loaded_yaml_file ||= YAML.load_file(Rails.root.join('config/prometheus/additional_metrics.yml'))
+      end
+    end
+  end
+end

lib/gitlab/prometheus/metric.rb

+module Gitlab
+  module Prometheus
+    class Metric
+      include ActiveModel::Model
+
+      attr_accessor :title, :required_metrics, :weight, :y_label, :queries
+
+      validates :title, :required_metrics, :weight, :y_label, :queries, presence: true
+
+      def initialize(params = {})
+        super(params)
+        @y_label ||= 'Values'
+      end
+    end
+  end
+end

lib/gitlab/prometheus/metric_group.rb

+module Gitlab
+  module Prometheus
+    class MetricGroup
+      include ActiveModel::Model
+
+      attr_accessor :name, :priority, :metrics
+      validates :name, :priority, :metrics, presence: true
+
+      def self.all
+        AdditionalMetricsParser.load_groups_from_yaml
+      end
+    end
+  end
+end

lib/gitlab/prometheus/parsing_error.rb

+module Gitlab
+  module Prometheus
+    ParsingError = Class.new(StandardError)
+  end
+end

lib/gitlab/prometheus/queries/additional_metrics_deployment_query.rb

+module Gitlab
+  module Prometheus
+    module Queries
+      class AdditionalMetricsDeploymentQuery < BaseQuery
+        include QueryAdditionalMetrics
+
+        def query(deployment_id)
+          Deployment.find_by(id: deployment_id).try do |deployment|
+            query_context = {
+              environment_slug: deployment.environment.slug,
+              environment_filter: %{container_name!="POD",environment="#{deployment.environment.slug}"},
+              timeframe_start: (deployment.created_at - 30.minutes).to_f,
+              timeframe_end: (deployment.created_at + 30.minutes).to_f
+            }
+
+            query_metrics(query_context)
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/prometheus/queries/additional_metrics_environment_query.rb

+module Gitlab
+  module Prometheus
+    module Queries
+      class AdditionalMetricsEnvironmentQuery < BaseQuery
+        include QueryAdditionalMetrics
+
+        def query(environment_id)
+          Environment.find_by(id: environment_id).try do |environment|
+            query_context = {
+              environment_slug: environment.slug,
+              environment_filter: %{container_name!="POD",environment="#{environment.slug}"},
+              timeframe_start: 8.hours.ago.to_f,
+              timeframe_end: Time.now.to_f
+            }
+
+            query_metrics(query_context)
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/prometheus/queries/base_query.rb

@@ -3,7 +3,7 @@ module Gitlab
     module Queries
       class BaseQuery
         attr_accessor :client
-        delegate :query_range, :query, to: :client, prefix: true
+        delegate :query_range, :query, :label_values, :series, to: :client, prefix: true
 
         def raw_memory_usage_query(environment_slug)
           %{avg(container_memory_usage_bytes{container_name!="POD",environment="#{environment_slug}"}) / 2^20}

lib/gitlab/prometheus/queries/deployment_query.rb

-module Gitlab::Prometheus::Queries
-  class DeploymentQuery < BaseQuery
-    def query(deployment_id)
-      deployment = Deployment.find_by(id: deployment_id)
-      environment_slug = deployment.environment.slug
+module Gitlab
+  module Prometheus
+    module Queries
+      class DeploymentQuery < BaseQuery
+        def query(deployment_id)
+          Deployment.find_by(id: deployment_id).try do |deployment|
+            environment_slug = deployment.environment.slug
 
-      memory_query = raw_memory_usage_query(environment_slug)
-      memory_avg_query = %{avg(avg_over_time(container_memory_usage_bytes{container_name!="POD",environment="#{environment_slug}"}[30m]))}
-      cpu_query = raw_cpu_usage_query(environment_slug)
-      cpu_avg_query = %{avg(rate(container_cpu_usage_seconds_total{container_name!="POD",environment="#{environment_slug}"}[30m])) * 100}
+            memory_query = raw_memory_usage_query(environment_slug)
+            memory_avg_query = %{avg(avg_over_time(container_memory_usage_bytes{container_name!="POD",environment="#{environment_slug}"}[30m]))}
+            cpu_query = raw_cpu_usage_query(environment_slug)
+            cpu_avg_query = %{avg(rate(container_cpu_usage_seconds_total{container_name!="POD",environment="#{environment_slug}"}[30m])) * 100}
 
-      timeframe_start = (deployment.created_at - 30.minutes).to_f
-      timeframe_end = (deployment.created_at + 30.minutes).to_f
+            timeframe_start = (deployment.created_at - 30.minutes).to_f
+            timeframe_end = (deployment.created_at + 30.minutes).to_f
 
-      {
-        memory_values: client_query_range(memory_query, start: timeframe_start, stop: timeframe_end),
-        memory_before: client_query(memory_avg_query, time: deployment.created_at.to_f),
-        memory_after: client_query(memory_avg_query, time: timeframe_end),
+            {
+              memory_values: client_query_range(memory_query, start: timeframe_start, stop: timeframe_end),
+              memory_before: client_query(memory_avg_query, time: deployment.created_at.to_f),
+              memory_after: client_query(memory_avg_query, time: timeframe_end),
 
-        cpu_values: client_query_range(cpu_query, start: timeframe_start, stop: timeframe_end),
-        cpu_before: client_query(cpu_avg_query, time: deployment.created_at.to_f),
-        cpu_after: client_query(cpu_avg_query, time: timeframe_end)
-      }
+              cpu_values: client_query_range(cpu_query, start: timeframe_start, stop: timeframe_end),
+              cpu_before: client_query(cpu_avg_query, time: deployment.created_at.to_f),
+              cpu_after: client_query(cpu_avg_query, time: timeframe_end)
+            }
+          end
+        end
+      end
     end
   end
 end

lib/gitlab/prometheus/queries/environment_query.rb

-module Gitlab::Prometheus::Queries
-  class EnvironmentQuery < BaseQuery
-    def query(environment_id)
-      environment = Environment.find_by(id: environment_id)
-      environment_slug = environment.slug
-      timeframe_start = 8.hours.ago.to_f
-      timeframe_end = Time.now.to_f
+module Gitlab
+  module Prometheus
+    module Queries
+      class EnvironmentQuery < BaseQuery
+        def query(environment_id)
+          Environment.find_by(id: environment_id).try do |environment|
+            environment_slug = environment.slug
+            timeframe_start = 8.hours.ago.to_f
+            timeframe_end = Time.now.to_f
 
-      memory_query = raw_memory_usage_query(environment_slug)
-      cpu_query = raw_cpu_usage_query(environment_slug)
+            memory_query = raw_memory_usage_query(environment_slug)
+            cpu_query = raw_cpu_usage_query(environment_slug)
 
-      {
-        memory_values: client_query_range(memory_query, start: timeframe_start, stop: timeframe_end),
-        memory_current: client_query(memory_query, time: timeframe_end),
-        cpu_values: client_query_range(cpu_query, start: timeframe_start, stop: timeframe_end),
-        cpu_current: client_query(cpu_query, time: timeframe_end)
-      }
+            {
+              memory_values: client_query_range(memory_query, start: timeframe_start, stop: timeframe_end),
+              memory_current: client_query(memory_query, time: timeframe_end),
+              cpu_values: client_query_range(cpu_query, start: timeframe_start, stop: timeframe_end),
+              cpu_current: client_query(cpu_query, time: timeframe_end)
+            }
+          end
+        end
+      end
     end
   end
 end

lib/gitlab/prometheus/queries/matched_metrics_query.rb

+module Gitlab
+  module Prometheus
+    module Queries
+      class MatchedMetricsQuery < BaseQuery
+        MAX_QUERY_ITEMS = 40.freeze
+
+        def query
+          groups_data.map do |group, data|
+            {
+              group: group.name,
+              priority: group.priority,
+              active_metrics: data[:active_metrics],
+              metrics_missing_requirements: data[:metrics_missing_requirements]
+            }
+          end
+        end
+
+        private
+
+        def groups_data
+          metrics_groups = groups_with_active_metrics(Gitlab::Prometheus::MetricGroup.all)
+          lookup = active_series_lookup(metrics_groups)
+
+          groups = {}
+
+          metrics_groups.each do |group|
+            groups[group] ||= { active_metrics: 0, metrics_missing_requirements: 0 }
+            active_metrics = group.metrics.count { |metric| metric.required_metrics.all?(&lookup.method(:has_key?)) }
+
+            groups[group][:active_metrics] += active_metrics
+            groups[group][:metrics_missing_requirements] += group.metrics.count - active_metrics
+          end
+
+          groups
+        end
+
+        def active_series_lookup(metric_groups)
+          timeframe_start = 8.hours.ago
+          timeframe_end = Time.now
+
+          series = metric_groups.flat_map(&:metrics).flat_map(&:required_metrics).uniq
+
+          lookup = series.each_slice(MAX_QUERY_ITEMS).flat_map do |batched_series|
+            client_series(*batched_series, start: timeframe_start, stop: timeframe_end)
+              .select(&method(:has_matching_label))
+              .map { |series_info| [series_info['__name__'], true] }
+          end
+          lookup.to_h
+        end
+
+        def has_matching_label(series_info)
+          series_info.key?('environment')
+        end
+
+        def available_metrics
+          @available_metrics ||= client_label_values || []
+        end
+
+        def filter_active_metrics(metric_group)
+          metric_group.metrics.select! do |metric|
+            metric.required_metrics.all?(&available_metrics.method(:include?))
+          end
+          metric_group
+        end
+
+        def groups_with_active_metrics(metric_groups)
+          metric_groups.map(&method(:filter_active_metrics)).select { |group| group.metrics.any? }
+        end
+
+        def metrics_with_required_series(metric_groups)
+          metric_groups.flat_map do |group|
+            group.metrics.select do |metric|
+              metric.required_metrics.all?(&available_metrics.method(:include?))
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/prometheus/queries/query_additional_metrics.rb

+module Gitlab
+  module Prometheus
+    module Queries
+      module QueryAdditionalMetrics
+        def query_metrics(query_context)
+          query_processor = method(:process_query).curry[query_context]
+
+          groups = matched_metrics.map do |group|
+            metrics = group.metrics.map do |metric|
+              {
+                title: metric.title,
+                weight: metric.weight,
+                y_label: metric.y_label,
+                queries: metric.queries.map(&query_processor).select(&method(:query_with_result))
+              }
+            end
+
+            {
+              group: group.name,
+              priority: group.priority,
+              metrics: metrics.select(&method(:metric_with_any_queries))
+            }
+          end
+
+          groups.select(&method(:group_with_any_metrics))
+        end
+
+        private
+
+        def metric_with_any_queries(metric)
+          metric[:queries]&.count&.> 0
+        end
+
+        def group_with_any_metrics(group)
+          group[:metrics]&.count&.> 0
+        end
+
+        def query_with_result(query)
+          query[:result]&.any? do |item|
+            item&.[](:values)&.any? || item&.[](:value)&.any?
+          end
+        end
+
+        def process_query(context, query)
+          query_with_result = query.dup
+          result =
+            if query.key?(:query_range)
+              client_query_range(query[:query_range] % context, start: context[:timeframe_start], stop: context[:timeframe_end])
+            else
+              client_query(query[:query] % context, time: context[:timeframe_end])
+            end
+          query_with_result[:result] = result&.map(&:deep_symbolize_keys)
+          query_with_result
+        end
+
+        def available_metrics
+          @available_metrics ||= client_label_values || []
+        end
+
+        def matched_metrics
+          result = Gitlab::Prometheus::MetricGroup.all.map do |group|
+            group.metrics.select! do |metric|
+              metric.required_metrics.all?(&available_metrics.method(:include?))
+            end
+            group
+          end
+
+          result.select { |group| group.metrics.any? }
+        end
+      end
+    end
+  end
+end

lib/gitlab/prometheus_client.rb

@@ -29,6 +29,14 @@ module Gitlab
       end
     end
 
+    def label_values(name = '__name__')
+      json_api_get("label/#{name}/values")
+    end
+
+    def series(*matches, start: 8.hours.ago, stop: Time.now)
+      json_api_get('series', 'match': matches, start: start.to_f, end: stop.to_f)
+    end
+
     private
 
     def json_api_get(type, args = {})

spec/controllers/application_controller_spec.rb

@@ -99,6 +99,36 @@ describe ApplicationController do
     end
   end
 
+  describe 'response format' do
+    controller(described_class) do
+      def index
+        respond_to do |format|
+          format.json do
+            head :ok
+          end
+        end
+      end
+    end
+
+    context 'when format is handled' do
+      let(:requested_format) { :json }
+
+      it 'returns 200 response' do
+        get :index, private_token: user.private_token, format: requested_format
+
+        expect(response).to have_http_status 200
+      end
+    end
+
+    context 'when format is not handled' do
+      it 'returns 404 response' do
+        get :index, private_token: user.private_token
+
+        expect(response).to have_http_status 404
+      end
+    end
+  end
+
   describe '#authenticate_user_from_rss_token' do
     describe "authenticating a user from an RSS token" do
       controller(described_class) do

spec/controllers/projects/deployments_controller_spec.rb

@@ -42,6 +42,7 @@ describe Projects::DeploymentsController do
     before do
       allow(controller).to receive(:deployment).and_return(deployment)
     end
+
     context 'when metrics are disabled' do
       before do
         allow(deployment).to receive(:has_metrics?).and_return false
@@ -108,6 +109,69 @@ describe Projects::DeploymentsController do
     end
   end
 
+  describe 'GET #additional_metrics' do
+    let(:deployment) { create(:deployment, project: project, environment: environment) }
+
+    before do
+      allow(controller).to receive(:deployment).and_return(deployment)
+    end
+
+    context 'when metrics are disabled' do
+      before do
+        allow(deployment).to receive(:has_metrics?).and_return false
+      end
+
+      it 'responds with not found' do
+        get :metrics, deployment_params(id: deployment.id)
+
+        expect(response).to be_not_found
+      end
+    end
+
+    context 'when metrics are enabled' do
+      let(:prometheus_service) { double('prometheus_service') }
+
+      before do
+        allow(deployment.project).to receive(:prometheus_service).and_return(prometheus_service)
+      end
+
+      context 'when environment has no metrics' do
+        before do
+          expect(deployment).to receive(:additional_metrics).and_return({})
+        end
+
+        it 'returns a empty response 204 response' do
+          get :additional_metrics, deployment_params(id: deployment.id, format: :json)
+          expect(response).to have_http_status(204)
+          expect(response.body).to eq('')
+        end
+      end
+
+      context 'when environment has some metrics' do
+        let(:empty_metrics) do
+          {
+            success: true,
+            metrics: {},
+            last_update: 42
+          }
+        end
+
+        before do
+          expect(deployment).to receive(:additional_metrics).and_return(empty_metrics)
+        end
+
+        it 'returns a metrics JSON document' do
+          get :additional_metrics, deployment_params(id: deployment.id, format: :json)
+
+          expect(response).to be_ok
+          expect(json_response['success']).to be(true)
+          expect(json_response['metrics']).to eq({})
+          expect(json_response['last_update']).to eq(42)
+        end
+      end
+    end
+  end
+
   def deployment_params(opts = {})
     opts.reverse_merge(namespace_id: project.namespace,
                        project_id: project,

spec/controllers/projects/environments_controller_spec.rb

@@ -318,6 +318,48 @@ describe Projects::EnvironmentsController do
     end
   end
 
+  describe 'GET #additional_metrics' do
+    before do
+      allow(controller).to receive(:environment).and_return(environment)
+    end
+
+    context 'when environment has no metrics' do
+      before do
+        expect(environment).to receive(:additional_metrics).and_return(nil)
+      end
+
+      context 'when requesting metrics as JSON' do
+        it 'returns a metrics JSON document' do
+          get :additional_metrics, environment_params(format: :json)
+
+          expect(response).to have_http_status(204)
+          expect(json_response).to eq({})
+        end
+      end
+    end
+
+    context 'when environment has some metrics' do
+      before do
+        expect(environment)
+          .to receive(:additional_metrics)
+                .and_return({
+                              success: true,
+                              data: {},
+                              last_update: 42
+                            })
+      end
+
+      it 'returns a metrics JSON document' do
+        get :additional_metrics, environment_params(format: :json)
+
+        expect(response).to be_ok
+        expect(json_response['success']).to be(true)
+        expect(json_response['data']).to eq({})
+        expect(json_response['last_update']).to eq(42)
+      end
+    end
+  end
+
   def environment_params(opts = {})
     opts.reverse_merge(namespace_id: project.namespace,
                        project_id: project,

spec/controllers/projects/prometheus_controller_spec.rb

+require('spec_helper')
+
+describe Projects::PrometheusController do
+  let(:user) { create(:user) }
+  let!(:project) { create(:empty_project) }
+
+  let(:prometheus_service) { double('prometheus_service') }
+
+  before do
+    allow(controller).to receive(:project).and_return(project)
+    allow(project).to receive(:prometheus_service).and_return(prometheus_service)
+
+    project.add_master(user)
+    sign_in(user)
+  end
+
+  describe 'GET #active_metrics' do
+    context 'when prometheus metrics are enabled' do
+      context 'when data is not present' do
+        before do
+          allow(prometheus_service).to receive(:matched_metrics).and_return({})
+        end
+
+        it 'returns no content response' do
+          get :active_metrics, project_params(format: :json)
+
+          expect(response).to have_http_status(204)
+        end
+      end
+
+      context 'when data is available' do
+        let(:sample_response) { { some_data: 1 } }
+
+        before do
+          allow(prometheus_service).to receive(:matched_metrics).and_return(sample_response)
+        end
+
+        it 'returns no content response' do
+          get :active_metrics, project_params(format: :json)
+
+          expect(response).to have_http_status(200)
+          expect(json_response).to eq(sample_response.deep_stringify_keys)
+        end
+      end
+
+      context 'when requesting non json response' do
+        it 'returns not found response' do
+          get :active_metrics, project_params
+
+          expect(response).to have_http_status(404)
+        end
+      end
+    end
+  end
+
+  def project_params(opts = {})
+    opts.reverse_merge(namespace_id: project.namespace, project_id: project)
+  end
+end

spec/factories/services.rb

@@ -25,6 +25,14 @@ FactoryGirl.define do
     })
   end
 
+  factory :prometheus_service do
+    project factory: :empty_project
+    active true
+    properties({
+      api_url: 'https://prometheus.example.com/'
+    })
+  end
+
   factory :jira_service do
     project factory: :empty_project
     active true

spec/fixtures/api/schemas/prometheus/additional_metrics_query_result.json

+{
+  "items": {
+    "properties": {
+      "group": {
+        "type": "string"
+      },
+      "metrics": {
+        "items": {
+          "properties": {
+            "queries": {
+              "items": {
+                "properties": {
+                  "query_range": {
+                    "type": "string"
+                  },
+                  "query": {
+                    "type": "string"
+                  },
+                  "result": {
+                    "type": "any"
+                  }
+                },
+                "type": "object"
+              },
+              "type": "array"
+            },
+            "title": {
+              "type": "string"
+            },
+            "weight": {
+              "type": "integer"
+            },
+            "y_label": {
+              "type": "string"
+            }
+          },
+          "type": "object"
+        },
+        "required": [
+          "metrics",
+          "title",
+          "weight"
+        ],
+        "type": "array"
+      },
+      "priority": {
+        "type": "integer"
+      }
+    },
+    "type": "object"
+  },
+  "required": [
+    "group",
+    "priority",
+    "metrics"
+  ],
+  "type": "array"
+}
\ No newline at end of file

spec/javascripts/fixtures/prometheus_service.rb

+require 'spec_helper'
+
+describe Projects::ServicesController, '(JavaScript fixtures)', type: :controller do
+  include JavaScriptFixturesHelpers
+
+  let(:admin)     { create(:admin) }
+  let(:namespace) { create(:namespace, name: 'frontend-fixtures' )}
+  let(:project)   { create(:project_empty_repo, namespace: namespace, path: 'services-project') }
+  let!(:service)  { create(:prometheus_service, project: project) }
+  
+  render_views
+
+  before(:all) do
+    clean_frontend_fixtures('services/prometheus')
+  end
+
+  before(:each) do
+    sign_in(admin)
+  end
+
+  it 'services/prometheus/prometheus_service.html.raw' do |example|
+    get :edit,
+      namespace_id: namespace,
+      project_id: project,
+      id: service.to_param
+
+    expect(response).to be_success
+    store_frontend_fixture(response, example.description)
+  end
+end

spec/javascripts/prometheus_metrics/mock_data.js

+export const metrics = [
+  {
+    group: 'Kubernetes',
+    priority: 1,
+    active_metrics: 4,
+    metrics_missing_requirements: 0,
+  },
+  {
+    group: 'HAProxy',
+    priority: 2,
+    active_metrics: 3,
+    metrics_missing_requirements: 0,
+  },
+  {
+    group: 'Apache',
+    priority: 3,
+    active_metrics: 5,
+    metrics_missing_requirements: 0,
+  },
+];
+
+export const missingVarMetrics = [
+  {
+    group: 'Kubernetes',
+    priority: 1,
+    active_metrics: 4,
+    metrics_missing_requirements: 0,
+  },
+  {
+    group: 'HAProxy',
+    priority: 2,
+    active_metrics: 3,
+    metrics_missing_requirements: 1,
+  },
+  {
+    group: 'Apache',
+    priority: 3,
+    active_metrics: 5,
+    metrics_missing_requirements: 3,
+  },
+];

spec/javascripts/prometheus_metrics/prometheus_metrics_spec.js

+import PrometheusMetrics from '~/prometheus_metrics/prometheus_metrics';
+import PANEL_STATE from '~/prometheus_metrics/constants';
+import { metrics, missingVarMetrics } from './mock_data';
+
+describe('PrometheusMetrics', () => {
+  const FIXTURE = 'services/prometheus/prometheus_service.html.raw';
+  preloadFixtures(FIXTURE);
+
+  beforeEach(() => {
+    loadFixtures(FIXTURE);
+  });
+
+  describe('constructor', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should initialize wrapper element refs on class object', () => {
+      expect(prometheusMetrics.$wrapper).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsPanel).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsCount).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsLoading).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsEmpty).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsList).toBeDefined();
+      expect(prometheusMetrics.$missingEnvVarPanel).toBeDefined();
+      expect(prometheusMetrics.$panelToggle).toBeDefined();
+      expect(prometheusMetrics.$missingEnvVarMetricCount).toBeDefined();
+      expect(prometheusMetrics.$missingEnvVarMetricsList).toBeDefined();
+    });
+
+    it('should initialize metadata on class object', () => {
+      expect(prometheusMetrics.backOffRequestCounter).toEqual(0);
+      expect(prometheusMetrics.activeMetricsEndpoint).toContain('/test');
+    });
+  });
+
+  describe('showMonitoringMetricsPanelState', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should show loading state when called with `loading`', () => {
+      prometheusMetrics.showMonitoringMetricsPanelState(PANEL_STATE.LOADING);
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeFalsy();
+      expect(prometheusMetrics.$monitoredMetricsEmpty.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$monitoredMetricsList.hasClass('hidden')).toBeTruthy();
+    });
+
+    it('should show metrics list when called with `list`', () => {
+      prometheusMetrics.showMonitoringMetricsPanelState(PANEL_STATE.LIST);
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$monitoredMetricsEmpty.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$monitoredMetricsList.hasClass('hidden')).toBeFalsy();
+    });
+
+    it('should show empty state when called with `empty`', () => {
+      prometheusMetrics.showMonitoringMetricsPanelState(PANEL_STATE.EMPTY);
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$monitoredMetricsEmpty.hasClass('hidden')).toBeFalsy();
+      expect(prometheusMetrics.$monitoredMetricsList.hasClass('hidden')).toBeTruthy();
+    });
+  });
+
+  describe('populateActiveMetrics', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should show monitored metrics list', () => {
+      prometheusMetrics.populateActiveMetrics(metrics);
+
+      const $metricsListLi = prometheusMetrics.$monitoredMetricsList.find('li');
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$monitoredMetricsList.hasClass('hidden')).toBeFalsy();
+
+      expect(prometheusMetrics.$monitoredMetricsCount.text()).toEqual('12');
+      expect($metricsListLi.length).toEqual(metrics.length);
+      expect($metricsListLi.first().find('.badge').text()).toEqual(`${metrics[0].active_metrics}`);
+    });
+
+    it('should show missing environment variables list', () => {
+      prometheusMetrics.populateActiveMetrics(missingVarMetrics);
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$missingEnvVarPanel.hasClass('hidden')).toBeFalsy();
+
+      expect(prometheusMetrics.$missingEnvVarMetricCount.text()).toEqual('2');
+      expect(prometheusMetrics.$missingEnvVarPanel.find('li').length).toEqual(2);
+      expect(prometheusMetrics.$missingEnvVarPanel.find('.flash-container')).toBeDefined();
+    });
+  });
+
+  describe('loadActiveMetrics', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should show loader animation while response is being loaded and hide it when request is complete', (done) => {
+      const deferred = $.Deferred();
+      spyOn($, 'getJSON').and.returnValue(deferred.promise());
+
+      prometheusMetrics.loadActiveMetrics();
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeFalsy();
+      expect($.getJSON).toHaveBeenCalledWith(prometheusMetrics.activeMetricsEndpoint);
+
+      deferred.resolve({ data: metrics, success: true });
+
+      setTimeout(() => {
+        expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+        done();
+      });
+    });
+
+    it('should show empty state if response failed to load', (done) => {
+      const deferred = $.Deferred();
+      spyOn($, 'getJSON').and.returnValue(deferred.promise());
+      spyOn(prometheusMetrics, 'populateActiveMetrics');
+
+      prometheusMetrics.loadActiveMetrics();
+
+      deferred.reject();
+
+      setTimeout(() => {
+        expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+        expect(prometheusMetrics.$monitoredMetricsEmpty.hasClass('hidden')).toBeFalsy();
+        done();
+      });
+    });
+
+    it('should populate metrics list once response is loaded', (done) => {
+      const deferred = $.Deferred();
+      spyOn($, 'getJSON').and.returnValue(deferred.promise());
+      spyOn(prometheusMetrics, 'populateActiveMetrics');
+
+      prometheusMetrics.loadActiveMetrics();
+
+      deferred.resolve({ data: metrics, success: true });
+
+      setTimeout(() => {
+        expect(prometheusMetrics.populateActiveMetrics).toHaveBeenCalledWith(metrics);
+        done();
+      });
+    });
+  });
+});

spec/lib/gitlab/prometheus/additional_metrics_parser_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Prometheus::AdditionalMetricsParser, lib: true do
+  include Prometheus::MetricBuilders
+
+  let(:parser_error_class) { Gitlab::Prometheus::ParsingError }
+
+  describe '#load_groups_from_yaml' do
+    subject { described_class.load_groups_from_yaml }
+
+    describe 'parsing sample yaml' do
+      let(:sample_yaml) do
+        <<-EOF.strip_heredoc
+          - group: group_a
+            priority: 1
+            metrics:
+              - title: "title"
+                required_metrics: [ metric_a, metric_b ]
+                weight: 1
+                queries: [{ query_range: 'query_range_a', label: label, unit: unit }]
+              - title: "title"
+                required_metrics: [metric_a]
+                weight: 1
+                queries: [{ query_range: 'query_range_empty' }]
+          - group: group_b
+            priority: 1
+            metrics: 
+              - title: title
+                required_metrics: ['metric_a']
+                weight: 1
+                queries: [{query_range: query_range_a}]
+        EOF
+      end
+
+      before do
+        allow(described_class).to receive(:load_yaml_file) { YAML.load(sample_yaml) }
+      end
+
+      it 'parses to two metric groups with 2 and 1 metric respectively' do
+        expect(subject.count).to eq(2)
+        expect(subject[0].metrics.count).to eq(2)
+        expect(subject[1].metrics.count).to eq(1)
+      end
+
+      it 'provide group data' do
+        expect(subject[0]).to have_attributes(name: 'group_a', priority: 1)
+        expect(subject[1]).to have_attributes(name: 'group_b', priority: 1)
+      end
+
+      it 'provides metrics data' do
+        metrics = subject.flat_map(&:metrics)
+
+        expect(metrics.count).to eq(3)
+        expect(metrics[0]).to have_attributes(title: 'title', required_metrics: %w(metric_a metric_b), weight: 1)
+        expect(metrics[1]).to have_attributes(title: 'title', required_metrics: %w(metric_a), weight: 1)
+        expect(metrics[2]).to have_attributes(title: 'title', required_metrics: %w{metric_a}, weight: 1)
+      end
+
+      it 'provides query data' do
+        queries = subject.flat_map(&:metrics).flat_map(&:queries)
+
+        expect(queries.count).to eq(3)
+        expect(queries[0]).to eq(query_range: 'query_range_a', label: 'label', unit: 'unit')
+        expect(queries[1]).to eq(query_range: 'query_range_empty')
+        expect(queries[2]).to eq(query_range: 'query_range_a')
+      end
+    end
+
+    shared_examples 'required field' do |field_name|
+      context "when #{field_name} is nil" do
+        before do
+          allow(described_class).to receive(:load_yaml_file) { YAML.load(field_missing) }
+        end
+
+        it 'throws parsing error' do
+          expect { subject }.to raise_error(parser_error_class, /#{field_name} can't be blank/i)
+        end
+      end
+
+      context "when #{field_name} are not specified" do
+        before do
+          allow(described_class).to receive(:load_yaml_file) { YAML.load(field_nil) }
+        end
+
+        it 'throws parsing error' do
+          expect { subject }.to raise_error(parser_error_class, /#{field_name} can't be blank/i)
+        end
+      end
+    end
+
+    describe 'group required fields' do
+      it_behaves_like 'required field', 'metrics' do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+          EOF
+        end
+      end
+
+      it_behaves_like 'required field', 'name' do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group:
+              priority: 1
+              metrics: []
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - priority: 1
+              metrics: []
+          EOF
+        end
+      end
+
+      it_behaves_like 'required field', 'priority' do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority:
+              metrics: []
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              metrics: []
+          EOF
+        end
+      end
+    end
+
+    describe 'metrics fields parsing' do
+      it_behaves_like 'required field', 'title' do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: 
+                required_metrics: []
+                weight: 1
+                queries: []
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - required_metrics: []
+                weight: 1
+                queries: []
+          EOF
+        end
+      end
+
+      it_behaves_like 'required field', 'required metrics' do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: title
+                required_metrics:
+                weight: 1
+                queries: []
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: title
+                weight: 1
+                queries: []
+          EOF
+        end
+      end
+
+      it_behaves_like 'required field', 'weight' do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: title
+                required_metrics: []
+                weight:
+                queries: []
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: title
+                required_metrics: []
+                queries: []
+          EOF
+        end
+      end
+
+      it_behaves_like 'required field', :queries do
+        let(:field_nil) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: title
+                required_metrics: []
+                weight: 1
+                queries:
+          EOF
+        end
+
+        let(:field_missing) do
+          <<-EOF.strip_heredoc
+            - group: group_a
+              priority: 1
+              metrics:
+              - title: title
+                required_metrics: []
+                weight: 1
+          EOF
+        end
+      end
+    end
+  end
+end

spec/lib/gitlab/prometheus/queries/additional_metrics_deployment_query_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Prometheus::Queries::AdditionalMetricsDeploymentQuery, lib: true do
+  include Prometheus::MetricBuilders
+
+  let(:client) { double('prometheus_client') }
+  let(:environment) { create(:environment, slug: 'environment-slug') }
+  let(:deployment) { create(:deployment, environment: environment) }
+
+  subject(:query_result) { described_class.new(client).query(deployment.id) }
+
+  around do |example|
+    Timecop.freeze(Time.local(2008, 9, 1, 12, 0, 0)) { example.run }
+  end
+
+  include_examples 'additional metrics query' do
+    it 'queries using specific time' do
+      expect(client).to receive(:query_range).with(anything,
+                                                   start: (deployment.created_at - 30.minutes).to_f,
+                                                   stop: (deployment.created_at + 30.minutes).to_f)
+
+      expect(query_result).not_to be_nil
+    end
+  end
+end

spec/lib/gitlab/prometheus/queries/additional_metrics_environment_query_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Prometheus::Queries::AdditionalMetricsEnvironmentQuery, lib: true do
+  include Prometheus::MetricBuilders
+
+  let(:client) { double('prometheus_client') }
+  let(:environment) { create(:environment, slug: 'environment-slug') }
+
+  subject(:query_result) { described_class.new(client).query(environment.id) }
+
+  around do |example|
+    Timecop.freeze { example.run }
+  end
+
+  include_examples 'additional metrics query' do
+    it 'queries using specific time' do
+      expect(client).to receive(:query_range).with(anything, start: 8.hours.ago.to_f, stop: Time.now.to_f)
+      expect(query_result).not_to be_nil
+    end
+  end
+end

spec/lib/gitlab/prometheus/queries/matched_metrics_query_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Prometheus::Queries::MatchedMetricsQuery, lib: true do
+  include Prometheus::MetricBuilders
+
+  let(:metric_group_class) { Gitlab::Prometheus::MetricGroup }
+  let(:metric_class) { Gitlab::Prometheus::Metric }
+
+  def series_info_with_environment(*more_metrics)
+    %w{metric_a metric_b}.concat(more_metrics).map { |metric_name| { '__name__' => metric_name, 'environment' => '' } }
+  end
+
+  let(:metric_names) { %w{metric_a metric_b} }
+  let(:series_info_without_environment) do
+    [{ '__name__' => 'metric_a' },
+     { '__name__' => 'metric_b' }]
+  end
+  let(:partialy_empty_series_info) { [{ '__name__' => 'metric_a', 'environment' => '' }] }
+  let(:empty_series_info) { [] }
+
+  let(:client) { double('prometheus_client') }
+
+  subject { described_class.new(client) }
+
+  context 'with one group where two metrics is found' do
+    before do
+      allow(metric_group_class).to receive(:all).and_return([simple_metric_group])
+      allow(client).to receive(:label_values).and_return(metric_names)
+    end
+
+    context 'both metrics in the group pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_with_environment)
+      end
+
+      it 'responds with both metrics as actve' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 2, metrics_missing_requirements: 0 }])
+      end
+    end
+
+    context 'none of the metrics pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_without_environment)
+      end
+
+      it 'responds with both metrics missing requirements' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 2 }])
+      end
+    end
+
+    context 'no series information found about the metrics' do
+      before do
+        allow(client).to receive(:series).and_return(empty_series_info)
+      end
+
+      it 'responds with both metrics missing requirements' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 2 }])
+      end
+    end
+
+    context 'one of the series info was not found' do
+      before do
+        allow(client).to receive(:series).and_return(partialy_empty_series_info)
+      end
+      it 'responds with one active and one missing metric' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 1, metrics_missing_requirements: 1 }])
+      end
+    end
+  end
+
+  context 'with one group where only one metric is found' do
+    before do
+      allow(metric_group_class).to receive(:all).and_return([simple_metric_group])
+      allow(client).to receive(:label_values).and_return('metric_a')
+    end
+
+    context 'both metrics in the group pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_with_environment)
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 1, metrics_missing_requirements: 0 }])
+      end
+    end
+
+    context 'no metrics in group pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_without_environment)
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 1 }])
+      end
+    end
+  end
+
+  context 'with two groups where metrics are found in each group' do
+    let(:second_metric_group) { simple_metric_group(name: 'nameb', metrics: simple_metrics(added_metric_name: 'metric_c')) }
+
+    before do
+      allow(metric_group_class).to receive(:all).and_return([simple_metric_group, second_metric_group])
+      allow(client).to receive(:label_values).and_return('metric_c')
+    end
+
+    context 'all metrics in both groups pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_with_environment('metric_c'))
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([
+                                      { group: 'name', priority: 1, active_metrics: 1, metrics_missing_requirements: 0 },
+                                      { group: 'nameb', priority: 1, active_metrics: 2, metrics_missing_requirements: 0 }
+                                    ]
+                                   )
+      end
+    end
+
+    context 'no metrics in groups pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_without_environment)
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([
+                                      { group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 1 },
+                                      { group: 'nameb', priority: 1, active_metrics: 0, metrics_missing_requirements: 2 }
+                                    ]
+                                   )
+      end
+    end
+  end
+end

spec/lib/gitlab/prometheus_client_spec.rb

@@ -119,6 +119,36 @@ describe Gitlab::PrometheusClient, lib: true do
     end
   end
 
+  describe '#series' do
+    let(:query_url) { prometheus_series_url('series_name', 'other_service') }
+
+    around do |example|
+      Timecop.freeze { example.run }
+    end
+
+    it 'calls endpoint and returns list of series' do
+      req_stub = stub_prometheus_request(query_url, body: prometheus_series('series_name'))
+      expected = prometheus_series('series_name').deep_stringify_keys['data']
+
+      expect(subject.series('series_name', 'other_service')).to eq(expected)
+
+      expect(req_stub).to have_been_requested
+    end
+  end
+
+  describe '#label_values' do
+    let(:query_url) { prometheus_label_values_url('__name__') }
+
+    it 'calls endpoint and returns label values' do
+      req_stub = stub_prometheus_request(query_url, body: prometheus_label_values)
+      expected = prometheus_label_values.deep_stringify_keys['data']
+
+      expect(subject.label_values('__name__')).to eq(expected)
+
+      expect(req_stub).to have_been_requested
+    end
+  end
+
   describe '#query_range' do
     let(:prometheus_query) { prometheus_memory_query('env-slug') }
     let(:query_url) { prometheus_query_range_url(prometheus_query) }

spec/models/deployment_spec.rb

@@ -30,7 +30,7 @@ describe Deployment, models: true do
   end
 
   describe '#includes_commit?' do
-    let(:project)     { create(:project, :repository) }
+    let(:project) { create(:project, :repository) }
     let(:environment) { create(:environment, project: project) }
     let(:deployment) do
       create(:deployment, environment: environment, sha: project.commit.id)
@@ -90,6 +90,36 @@ describe Deployment, models: true do
     end
   end
 
+  describe '#additional_metrics' do
+    let(:project) { create(:project) }
+    let(:deployment) { create(:deployment, project: project) }
+
+    subject { deployment.additional_metrics }
+
+    context 'metrics are disabled' do
+      it { is_expected.to eq({}) }
+    end
+
+    context 'metrics are enabled' do
+      let(:simple_metrics) do
+        {
+          success: true,
+          metrics: {},
+          last_update: 42
+        }
+      end
+
+      let(:prometheus_service) { double('prometheus_service') }
+
+      before do
+        allow(project).to receive(:prometheus_service).and_return(prometheus_service)
+        allow(prometheus_service).to receive(:additional_deployment_metrics).and_return(simple_metrics)
+      end
+
+      it { is_expected.to eq(simple_metrics.merge({ deployment_time: deployment.created_at.to_i })) }
+    end
+  end
+
   describe '#stop_action' do
     let(:build) { create(:ci_build) }
 

spec/models/environment_spec.rb

@@ -432,6 +432,99 @@ describe Environment, models: true do
     end
   end
 
+  describe '#has_metrics?' do
+    subject { environment.has_metrics? }
+
+    context 'when the enviroment is available' do
+      context 'with a deployment service' do
+        let(:project) { create(:prometheus_project) }
+
+        context 'and a deployment' do
+          let!(:deployment) { create(:deployment, environment: environment) }
+          it { is_expected.to be_truthy }
+        end
+
+        context 'but no deployments' do
+          it { is_expected.to be_falsy }
+        end
+      end
+
+      context 'without a monitoring service' do
+        it { is_expected.to be_falsy }
+      end
+    end
+
+    context 'when the environment is unavailable' do
+      let(:project) { create(:prometheus_project) }
+
+      before do
+        environment.stop
+      end
+
+      it { is_expected.to be_falsy }
+    end
+  end
+
+  describe '#additional_metrics' do
+    let(:project) { create(:prometheus_project) }
+    subject { environment.additional_metrics }
+
+    context 'when the environment has additional metrics' do
+      before do
+        allow(environment).to receive(:has_additional_metrics?).and_return(true)
+      end
+
+      it 'returns the additional metrics from the deployment service' do
+        expect(project.prometheus_service).to receive(:additional_environment_metrics)
+                                                .with(environment)
+                                                .and_return(:fake_metrics)
+
+        is_expected.to eq(:fake_metrics)
+      end
+    end
+
+    context 'when the environment does not have metrics' do
+      before do
+        allow(environment).to receive(:has_additional_metrics?).and_return(false)
+      end
+
+      it { is_expected.to be_nil }
+    end
+  end
+
+  describe '#has_additional_metrics??' do
+    subject { environment.has_additional_metrics? }
+
+    context 'when the enviroment is available' do
+      context 'with a deployment service' do
+        let(:project) { create(:prometheus_project) }
+
+        context 'and a deployment' do
+          let!(:deployment) { create(:deployment, environment: environment) }
+          it { is_expected.to be_truthy }
+        end
+
+        context 'but no deployments' do
+          it { is_expected.to be_falsy }
+        end
+      end
+
+      context 'without a monitoring service' do
+        it { is_expected.to be_falsy }
+      end
+    end
+
+    context 'when the environment is unavailable' do
+      let(:project) { create(:prometheus_project) }
+
+      before do
+        environment.stop
+      end
+
+      it { is_expected.to be_falsy }
+    end
+  end
+
   describe '#slug' do
     it "is automatically generated" do
       expect(environment.slug).not_to be_nil

spec/models/project_services/prometheus_service_spec.rb

@@ -65,7 +65,7 @@ describe PrometheusService, models: true, caching: true do
       end
 
       it 'returns reactive data' do
-        is_expected.to eq(prometheus_data)
+        is_expected.to eq(prometheus_metrics_data)
       end
     end
   end
@@ -86,7 +86,7 @@ describe PrometheusService, models: true, caching: true do
       end
 
       it 'returns reactive data' do
-        is_expected.to eq(prometheus_data.merge(deployment_time: deployment.created_at.to_i))
+        is_expected.to eq(prometheus_metrics_data.merge(deployment_time: deployment.created_at.to_i))
       end
     end
   end
@@ -116,6 +116,7 @@ describe PrometheusService, models: true, caching: true do
       end
 
       it { expect(subject.to_json).to eq(prometheus_data.to_json) }
+      it { expect(subject.to_json).to eq(prometheus_data.to_json) }
     end
 
     [404, 500].each do |status|

spec/support/api/schema_matcher.rb

+def schema_path(schema)
+  schema_directory = "#{Dir.pwd}/spec/fixtures/api/schemas"
+  "#{schema_directory}/#{schema}.json"
+end
+
 RSpec::Matchers.define :match_response_schema do |schema, **options|
   match do |response|
-    schema_directory = "#{Dir.pwd}/spec/fixtures/api/schemas"
-    schema_path = "#{schema_directory}/#{schema}.json"
+    JSON::Validator.validate!(schema_path(schema), response.body, options)
+  end
+end
 
-    JSON::Validator.validate!(schema_path, response.body, options)
+RSpec::Matchers.define :match_schema do |schema, **options|
+  match do |data|
+    JSON::Validator.validate!(schema_path(schema), data, options)
   end
 end

spec/support/prometheus/additional_metrics_shared_examples.rb

+RSpec.shared_examples 'additional metrics query' do
+  include Prometheus::MetricBuilders
+
+  let(:metric_group_class) { Gitlab::Prometheus::MetricGroup }
+  let(:metric_class) { Gitlab::Prometheus::Metric }
+
+  let(:metric_names) { %w{metric_a metric_b} }
+
+  let(:query_range_result) do
+    [{ 'metric': {}, 'values': [[1488758662.506, '0.00002996364761904785'], [1488758722.506, '0.00003090239047619091']] }]
+  end
+
+  before do
+    allow(client).to receive(:label_values).and_return(metric_names)
+    allow(metric_group_class).to receive(:all).and_return([simple_metric_group(metrics: [simple_metric])])
+  end
+
+  context 'with one group where two metrics is found' do
+    before do
+      allow(metric_group_class).to receive(:all).and_return([simple_metric_group])
+    end
+
+    context 'some queries return results' do
+      before do
+        allow(client).to receive(:query_range).with('query_range_a', any_args).and_return(query_range_result)
+        allow(client).to receive(:query_range).with('query_range_b', any_args).and_return(query_range_result)
+        allow(client).to receive(:query_range).with('query_range_empty', any_args).and_return([])
+      end
+
+      it 'return group data only for queries with results' do
+        expected = [
+          {
+            group: 'name',
+            priority: 1,
+            metrics: [
+              {
+                title: 'title', weight: 1, y_label: 'Values', queries: [
+                { query_range: 'query_range_a', result: query_range_result },
+                { query_range: 'query_range_b', label: 'label', unit: 'unit', result: query_range_result }
+              ]
+              }
+            ]
+          }
+        ]
+
+        expect(query_result).to match_schema('prometheus/additional_metrics_query_result')
+        expect(query_result).to eq(expected)
+      end
+    end
+  end
+
+  context 'with two groups with one metric each' do
+    let(:metrics) { [simple_metric(queries: [simple_query])] }
+    before do
+      allow(metric_group_class).to receive(:all).and_return(
+        [
+          simple_metric_group(name: 'group_a', metrics: [simple_metric(queries: [simple_query])]),
+          simple_metric_group(name: 'group_b', metrics: [simple_metric(title: 'title_b', queries: [simple_query('b')])])
+        ])
+      allow(client).to receive(:label_values).and_return(metric_names)
+    end
+
+    context 'both queries return results' do
+      before do
+        allow(client).to receive(:query_range).with('query_range_a', any_args).and_return(query_range_result)
+        allow(client).to receive(:query_range).with('query_range_b', any_args).and_return(query_range_result)
+      end
+
+      it 'return group data both queries' do
+        queries_with_result_a = { queries: [{ query_range: 'query_range_a', result: query_range_result }] }
+        queries_with_result_b = { queries: [{ query_range: 'query_range_b', result: query_range_result }] }
+
+        expect(query_result).to match_schema('prometheus/additional_metrics_query_result')
+
+        expect(query_result.count).to eq(2)
+        expect(query_result).to all(satisfy { |r| r[:metrics].count == 1 })
+
+        expect(query_result[0][:metrics].first).to include(queries_with_result_a)
+        expect(query_result[1][:metrics].first).to include(queries_with_result_b)
+      end
+    end
+
+    context 'one query returns result' do
+      before do
+        allow(client).to receive(:query_range).with('query_range_a', any_args).and_return(query_range_result)
+        allow(client).to receive(:query_range).with('query_range_b', any_args).and_return([])
+      end
+
+      it 'return group data only for query with results' do
+        queries_with_result = { queries: [{ query_range: 'query_range_a', result: query_range_result }] }
+
+        expect(query_result).to match_schema('prometheus/additional_metrics_query_result')
+
+        expect(query_result.count).to eq(1)
+        expect(query_result).to all(satisfy { |r| r[:metrics].count == 1 })
+
+        expect(query_result.first[:metrics].first).to include(queries_with_result)
+      end
+    end
+  end
+end

spec/support/prometheus/metric_builders.rb

+module Prometheus
+  module MetricBuilders
+    def simple_query(suffix = 'a', **opts)
+      { query_range: "query_range_#{suffix}" }.merge(opts)
+    end
+
+    def simple_queries
+      [simple_query, simple_query('b', label: 'label', unit: 'unit')]
+    end
+
+    def simple_metric(title: 'title', required_metrics: [], queries: [simple_query])
+      Gitlab::Prometheus::Metric.new(title: title, required_metrics: required_metrics, weight: 1, queries: queries)
+    end
+
+    def simple_metrics(added_metric_name: 'metric_a')
+      [
+        simple_metric(required_metrics: %W(#{added_metric_name} metric_b), queries: simple_queries),
+        simple_metric(required_metrics: [added_metric_name], queries: [simple_query('empty')]),
+        simple_metric(required_metrics: %w{metric_c})
+      ]
+    end
+
+    def simple_metric_group(name: 'name', metrics: simple_metrics)
+      Gitlab::Prometheus::MetricGroup.new(name: name, priority: 1, metrics: metrics)
+    end
+  end
+end

spec/support/prometheus_helpers.rb

@@ -36,6 +36,19 @@ module PrometheusHelpers
     "https://prometheus.example.com/api/v1/query_range?#{query}"
   end
 
+  def prometheus_label_values_url(name)
+    "https://prometheus.example.com/api/v1/label/#{name}/values"
+  end
+
+  def prometheus_series_url(*matches, start: 8.hours.ago, stop: Time.now)
+    query = {
+      match: matches,
+      start: start.to_f,
+      end: stop.to_f
+    }.to_query
+    "https://prometheus.example.com/api/v1/series?#{query}"
+  end
+
   def stub_prometheus_request(url, body: {}, status: 200)
     WebMock.stub_request(:get, url)
       .to_return({
@@ -85,6 +98,19 @@ module PrometheusHelpers
   def prometheus_data(last_update: Time.now.utc)
     {
       success: true,
+      data: {
+        memory_values: prometheus_values_body('matrix').dig(:data, :result),
+        memory_current: prometheus_value_body('vector').dig(:data, :result),
+        cpu_values: prometheus_values_body('matrix').dig(:data, :result),
+        cpu_current: prometheus_value_body('vector').dig(:data, :result)
+      },
+      last_update: last_update
+    }
+  end
+
+  def prometheus_metrics_data(last_update: Time.now.utc)
+    {
+      success: true,
       metrics: {
         memory_values: prometheus_values_body('matrix').dig(:data, :result),
         memory_current: prometheus_value_body('vector').dig(:data, :result),
@@ -140,4 +166,37 @@ module PrometheusHelpers
       }
     }
   end
+
+  def prometheus_label_values
+    {
+      'status': 'success',
+      'data': %w(job_adds job_controller_rate_limiter_use job_depth job_queue_latency job_work_duration_sum up)
+    }
+  end
+
+  def prometheus_series(name)
+    {
+      'status': 'success',
+      'data': [
+        {
+          '__name__': name,
+          'container_name': 'gitlab',
+          'environment': 'mattermost',
+          'id': '/docker/9953982f95cf5010dfc59d7864564d5f188aaecddeda343699783009f89db667',
+          'image': 'gitlab/gitlab-ce:8.15.4-ce.1',
+          'instance': 'minikube',
+          'job': 'kubernetes-nodes',
+          'name': 'k8s_gitlab.e6611886_mattermost-4210310111-77z8r_gitlab_2298ae6b-da24-11e6-baee-8e7f67d0eb3a_43536cb6',
+          'namespace': 'gitlab',
+          'pod_name': 'mattermost-4210310111-77z8r'
+        },
+        {
+          '__name__': name,
+          'id': '/docker',
+          'instance': 'minikube',
+          'job': 'kubernetes-nodes'
+        }
+      ]
+    }
+  end
 end