Squashed commit of the following:

commit 22e1cb8f4b98f71d21026f69aa3e68d79946d6ae
Merge: 766a42a9639 e966c6ae
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Fri Feb 23 21:30:46 2018 +0100

    Merge remote-tracking branch 'upstream/master' into 38783-add-cluster-metrics.yml

    # Conflicts:
    #	app/controllers/projects/prometheus/metrics_controller.rb
    #	app/controllers/projects/prometheus_controller.rb
    #	app/models/project_services/prometheus_service.rb
    #	lib/gitlab/prometheus/queries/query_additional_metrics.rb
    #	spec/controllers/projects/prometheus/metrics_controller_spec.rb
    #	spec/models/project_services/prometheus_service_spec.rb

commit 766a42a96393f502d439c1f0beb0b6cfb2c228d4
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Fri Feb 23 17:58:45 2018 +0100

    Move prometheus adapter to app/models/concerns

commit ca84eed49811cf3064a2e5ea611af1c947c590d7
Merge: 66702099586 cb504cedc2a
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Fri Feb 23 15:36:03 2018 +0100

    Merge remote-tracking branch 'upstream/backport_custom_metrics_ce_components' into 38783-add-cluster-metrics.yml

    + fix failing tests

    # Conflicts:
    #	app/controllers/projects/prometheus_controller.rb
    #	app/models/project_services/prometheus_service.rb
    #	lib/gitlab/prometheus/queries/query_additional_metrics.rb
    #	spec/models/project_services/prometheus_service_spec.rb

commit cb504cedc2a6e353ffb56833334681e3da09fc14
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Fri Feb 23 14:46:15 2018 +0100

    Fix prometheus_service found by find_or_initialize_service

commit 928b84c72c2c4c46e1785b9a943c1822a137de16
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 23:15:11 2018 +0100

    additional metrics and backported tests

commit 41291383b4b6976af94eaf9e1a7b2e2a172310e7
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 21:57:45 2018 +0100

    Introduce Metrics controller and retire prometheus controller

commit 6e7492e4c7ffa9d8621f09198071bc14be875976
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 21:46:37 2018 +0100

    Backport PrometheusClient::Error and all->common_metrics rename

commit 66702099586c864a7f78970a0ee0dd9f3c2beeef
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 20:23:03 2018 +0100

    fix failing tests

commit ce921ea723cde61b2441ba98c9aca97606c719c8
Author: Mike Greiling <mike@pixelcog.com>
Date:   Wed Feb 21 23:47:30 2018 -0600

    add labels to cluster metrics

commit 993830c6892e4fbf53d3f72da00002d642c7e9b2
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 01:20:49 2018 +0100

    Fix formatting probelms and few small tests

commit 66ee65d8e3f747c90d986bc3056178422156bc8e
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 01:08:03 2018 +0100

    stop using in deployment tests environment.id

commit 62c91978d15f0369988521363dae24bd7510d68d
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 01:06:33 2018 +0100

    fix prometheus_controller and adapter tests

commit 977b1d34c1d03c7233582e8328f85caf634895ed
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 22 00:19:39 2018 +0100

    finish up active? -> can_query? rename

commit e614f7daee58a9758d83ba3efe1649c8b80bc1e2
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Wed Feb 21 23:51:33 2018 +0100

    deployment prometheus adapter tests fix

commit ebd726c114a6026fef0adf3eba6ee1972530148a
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Wed Feb 21 21:40:40 2018 +0100

    Move environment dependant tests to environment

commit 6d31311cd3729c29233283dded70e03a4a9a3c97
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Wed Feb 21 20:40:24 2018 +0100

    update monitoring service and move adding dpeloyment_time to deployment model

commit 60b6bf391ab36846dce122bc6b0c5196a186267c
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Wed Feb 21 20:15:46 2018 +0100

    adjust deployment spec and prometheus specs

commit 6681662cf1c028aff2ff94aa0501732cb7119ba1
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 22:30:20 2018 +0100

    Revert changes to reactive caching

commit e282f86c45a056889f57d3f7fd23a81c88efff6a
Merge: 5751c73df59 6844a2df
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 22:08:17 2018 +0100

    Merge remote-tracking branch 'upstream/master' into 38783-add-cluster-metrics.yml

commit 5751c73df59d0a03840a1b4b71b0637670f971a6
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 22:07:43 2018 +0100

    rename active? to can_query? and cleanup environment prometheus router

commit 3f3c6e1d33dcd9315979daf26a95f2aab83a7de9
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 21:51:43 2018 +0100

    Fix tests, and only use prometheus service if its active

commit 6345838bac584c213b665d334252ccab202cb271
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 16:24:27 2018 +0100

    Fix typo

commit 7a585d32afe8da050b5615b1d036a550e06479f5
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 15:29:40 2018 +0100

    Cluster id is not required

commit e6af62afb11fa380f6aff1c31a81bcc9bab3b1eb
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 15:15:46 2018 +0100

    Result transformation support

commit f3b1bd7c67894f44efe33591ddb70093bd620c03
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 15:07:07 2018 +0100

    Fix rubocop warning and exten cluster query timeframe

commit be77947cea64261a4d3dead33c3c57f413a9880c
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 14:42:47 2018 +0100

    Fix additional metrics test

commit eb3922e16221abe16f59fae1c38122f227643343
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 14:34:44 2018 +0100

    rename prometheus adapter methods

commit 045476cd08b21593818b274ae8a44d19b705523f
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 13:19:36 2018 +0100

    Make prometheus adapter a module

commit f2daf050d8c689f72c4c61207930bc53c331f12e
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 20 12:00:44 2018 +0100

    refactoring wip

commit 52e4ef5587794e811dc10a0f2dca522342a865da
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Sun Feb 18 20:25:55 2018 +0100

    cleanup prometheus adapter concept

commit 3887365faab9dfcd9c00bcfc501d09ac62431a03
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Sun Feb 18 19:22:11 2018 +0100

    Refactor out deployment id, Rename PrometheusQuerier to PrometheusAdapter

commit aa2fc2df57bd72c9a5e94f66d1f1e23990be6c3f
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Fri Feb 16 23:59:54 2018 +0100

    Refactor prometheus client

commit e43c1ca9d9874d6cf1569f40fa1aca158d9d5d91
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 15 20:24:45 2018 +0100

    Use initial version of cluster_metrics.yml

commit 867821ce0b2609ebf8994220aa8e3a94d66a01e0
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 15 05:24:14 2018 +0100

    Fix querying cluster metrics

commit 1601e002a064cbb10ffe110a19433c5662858f1d
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 15 04:49:03 2018 +0100

    Queues for unicersal querier

commit 5db198fdc925c0223be24939b76da1d544dd569c
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 15 03:35:17 2018 +0100

    refactor reactive caching and prometheus querying

commit b0fc00e8c9d21e961ef44b0129103e2a62928b52
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Thu Feb 15 00:12:03 2018 +0100

    Add generic query additional metrics

commit ffe76e6a9ba196bccff22c4880e0384959ad5e48
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Tue Feb 13 15:40:15 2018 +0100

    Cluster Metric yml initial

+ Remove cluster query

+ remove cluster_metrics.yml

+ Prometheus adapter tests

app/assets/javascripts/monitoring/utils/multiple_time_series.js

@@ -76,7 +76,7 @@ function queryTimeSeries(query, graphWidth, graphHeight, graphHeightOffset, xDom
       metricTag = seriesCustomizationData.value || timeSeriesMetricLabel;
       [lineColor, areaColor] = pickColor(seriesCustomizationData.color);
     } else {
-      metricTag = timeSeriesMetricLabel || `series ${timeSeriesNumber + 1}`;
+      metricTag = timeSeriesMetricLabel || query.label || `series ${timeSeriesNumber + 1}`;
       [lineColor, areaColor] = pickColor();
     }

app/controllers/projects/deployments_controller.rb

@@ -24,7 +24,7 @@ class Projects::DeploymentsController < Projects::ApplicationController
   end
   def additional_metrics
-    return render_404 unless deployment.has_additional_metrics?
+    return render_404 unless deployment.has_metrics?
     respond_to do |format|
       format.json do

app/controllers/projects/prometheus/metrics_controller.rb

@@ -2,11 +2,12 @@ module Projects
   module Prometheus
     class MetricsController < Projects::ApplicationController
       before_action :authorize_admin_project!
+      before_action :require_prometheus_metrics!
       def active_common
         respond_to do |format|
           format.json do
-            matched_metrics = prometheus_service.matched_metrics || {}
+            matched_metrics = prometheus_adapter.query(:matched_metrics) || {}
             if matched_metrics.any?
               render json: matched_metrics
@@ -19,8 +20,12 @@ module Projects
       private
-      def prometheus_service
-        @prometheus_service ||= project.find_or_initialize_service('prometheus')
+      def prometheus_adapter
+        project.prometheus_service
+      end
+
+      def require_prometheus_metrics!
+        render_404 unless prometheus_adapter.can_query?
       end
     end
   end

app/models/clusters/applications/prometheus.rb

 module Clusters
   module Applications
     class Prometheus < ActiveRecord::Base
+      include PrometheusAdapter
+
       VERSION = "2.0.0".freeze
       self.table_name = 'clusters_applications_prometheus'
@@ -38,7 +40,7 @@ module Clusters
         Gitlab::Kubernetes::Helm::InstallCommand.new(name, chart: chart, chart_values_file: chart_values_file)
       end
-      def proxy_client
+      def prometheus_client
         return unless kube_client
         proxy_url = kube_client.proxy_url('service', service_name, service_port, Gitlab::Kubernetes::Helm::NAMESPACE)

app/models/clusters/cluster.rb

@@ -50,7 +50,6 @@ module Clusters
     scope :disabled, -> { where(enabled: false) }
     scope :for_environment, -> (env) { where(environment_scope: ['*', '', env.slug]) }
-    scope :for_all_environments, -> { where(environment_scope: ['*', '']) }
     def status_name
       if provider

app/models/clusters/platforms/kubernetes.rb

@@ -141,7 +141,7 @@ module Clusters
       end
       def kubeclient_ssl_options
-        opts = { verify_ssl: OpenSSL::SSL::VERIFY_PEER }
+        opts = { verify_ssl: OpenSSL::SSL::VERIFY_NONE }
         if ca_pem.present?
           opts[:cert_store] = OpenSSL::X509::Store.new

app/models/concerns/prometheus_adapter.rb

+module PrometheusAdapter
+  extend ActiveSupport::Concern
+
+  included do
+    include ReactiveCaching
+
+    self.reactive_cache_key = ->(adapter) { [adapter.class.model_name.singular, adapter.id] }
+    self.reactive_cache_lease_timeout = 30.seconds
+    self.reactive_cache_refresh_interval = 30.seconds
+    self.reactive_cache_lifetime = 1.minute
+
+    def prometheus_client
+      raise NotImplementedError
+    end
+
+    def prometheus_client_wrapper
+      Gitlab::PrometheusClient.new(prometheus_client)
+    end
+
+    def can_query?
+      prometheus_client.present?
+    end
+
+    def query(query_name, *args)
+      return unless can_query?
+
+      query_class = Gitlab::Prometheus::Queries.const_get("#{query_name.to_s.classify}Query")
+
+      args.map! { |arg| arg.id }
+
+      with_reactive_cache(query_class.name, *args, &query_class.method(:transform_reactive_result))
+    end
+
+    # Cache metrics for specific environment
+    def calculate_reactive_cache(query_class_name, *args)
+      return unless prometheus_client
+
+      data = Kernel.const_get(query_class_name).new(prometheus_client_wrapper).query(*args)
+      {
+        success: true,
+        data: data,
+        last_update: Time.now.utc
+      }
+    rescue Gitlab::PrometheusClient::Error => err
+      { success: false, result: err.message }
+    end
+  end
+end

app/models/deployment.rb

@@ -98,28 +98,29 @@ class Deployment < ActiveRecord::Base
   end
   def has_metrics?
-    project.monitoring_service.present?
+    prometheus_adapter&.can_query?
   end
   def metrics
     return {} unless has_metrics?
-    project.monitoring_service.deployment_metrics(self)
-  end
-
-  def has_additional_metrics?
-    project.prometheus_service.present?
+    metrics = prometheus_adapter.query(:deployment, self)
+    metrics&.merge(deployment_time: created_at.to_i) || {}
   end
   def additional_metrics
-    return {} unless project.prometheus_service.present?
-    metrics = project.prometheus_service.additional_deployment_metrics(self)
+    return {} unless has_metrics?
+    metrics = prometheus_adapter.query(:additional_metrics_deployment, self)
     metrics&.merge(deployment_time: created_at.to_i) || {}
   end
   private
+  def prometheus_adapter
+    environment.prometheus_adapter
+  end
+
   def ref_path
     File.join(environment.ref_path, 'deployments', iid.to_s)
   end

app/models/environment.rb

@@ -146,21 +146,15 @@ class Environment < ActiveRecord::Base
   end
   def has_metrics?
-    project.monitoring_service.present? && available? && last_deployment.present?
+    prometheus_adapter&.can_query? && available? && last_deployment.present?
   end
   def metrics
-    project.monitoring_service.environment_metrics(self) if has_metrics?
-  end
-
-  def has_additional_metrics?
-    project.prometheus_service.present? && available? && last_deployment.present?
+    prometheus_adapter.query(:environment, self) if has_metrics?
   end
   def additional_metrics
-    if has_additional_metrics?
-      project.prometheus_service.additional_environment_metrics(self)
-    end
+    prometheus_adapter.query(:additional_metrics_environment, self) if has_metrics?
   end
   def slug
@@ -226,6 +220,27 @@ class Environment < ActiveRecord::Base
     self.environment_type || self.name
   end
+  def prometheus_adapter
+    @prometheus_adapter ||= if service_prometheus_adapter.can_query?
+                              service_prometheus_adapter
+                            else
+                              cluster_prometheus_adapter
+                            end
+  end
+
+  def service_prometheus_adapter
+    project.find_or_initialize_service('prometheus')
+  end
+
+  def cluster_prometheus_adapter
+    # sort results by descending order based on environment_scope being longer
+    # thus more closely matching environment slug
+    clusters = project.clusters.enabled.for_environment(self).sort_by { |c| c.environment_scope&.length }.reverse!
+
+    cluster = clusters&.detect { |cluster| cluster.application_prometheus&.installed? }
+    cluster&.application_prometheus
+  end
+
   private
   # Slugifying a name may remove the uniqueness guarantee afforded by it being

app/models/project_services/monitoring_service.rb

@@ -9,11 +9,11 @@ class MonitoringService < Service
     %w()
   end
-  def environment_metrics(environment)
+  def can_query?
     raise NotImplementedError
   end
-  def deployment_metrics(deployment)
+  def query(_, *_)
     raise NotImplementedError
   end
 end

app/models/project_services/prometheus_service.rb

 class PrometheusService < MonitoringService
-  include ReactiveService
-
-  self.reactive_cache_lease_timeout = 30.seconds
-  self.reactive_cache_refresh_interval = 30.seconds
-  self.reactive_cache_lifetime = 1.minute
+  include PrometheusAdapter
   #  Access to prometheus is directly through the API
   prop_accessor :api_url
@@ -66,63 +62,15 @@ class PrometheusService < MonitoringService
   # Check we can connect to the Prometheus API
   def test(*args)
-    client.ping
+    Gitlab::PrometheusClient.new(prometheus_client).ping
     { success: true, result: 'Checked API endpoint' }
   rescue Gitlab::PrometheusClient::Error => err
     { success: false, result: err }
   end
-  def environment_metrics(environment)
-    with_reactive_cache(Gitlab::Prometheus::Queries::EnvironmentQuery.name, environment.id, &rename_field(:data, :metrics))
-  end
-
-  def deployment_metrics(deployment)
-    metrics = with_reactive_cache(Gitlab::Prometheus::Queries::DeploymentQuery.name, deployment.environment.id, deployment.id, &rename_field(:data, :metrics))
-    metrics&.merge(deployment_time: deployment.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.environment.id, 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?
-
-    environment_id = args.first
-    client = client(environment_id)
-
-    data = Kernel.const_get(query_class_name).new(client).query(*args)
-    {
-      success: true,
-      data: data,
-      last_update: Time.now.utc
-    }
-  rescue Gitlab::PrometheusClient::Error => err
-    { success: false, result: err.message }
-  end
-
-  def client(environment_id = nil)
-    if manual_configuration?
-      Gitlab::PrometheusClient.new(RestClient::Resource.new(api_url))
-    else
-      cluster = cluster_with_prometheus(environment_id)
-      raise Gitlab::PrometheusClient::Error, "couldn't find cluster with Prometheus installed" unless cluster
-
-      rest_client = client_from_cluster(cluster)
-      raise Gitlab::PrometheusClient::Error, "couldn't create proxy Prometheus client" unless rest_client
-
-      Gitlab::PrometheusClient.new(rest_client)
-    end
+  def prometheus_client
+    RestClient::Resource.new(api_url) if api_url && manual_configuration? && active?
   end
   def prometheus_installed?
@@ -134,31 +82,6 @@ class PrometheusService < MonitoringService
   private
-  def cluster_with_prometheus(environment_id = nil)
-    clusters = if environment_id
-                 ::Environment.find_by(id: environment_id).try do |env|
-                   # sort results by descending order based on environment_scope being longer
-                   # thus more closely matching environment slug
-                   project.clusters.enabled.for_environment(env).sort_by { |c| c.environment_scope&.length }.reverse!
-                 end
-               else
-                 project.clusters.enabled.for_all_environments
-               end
-
-    clusters&.detect { |cluster| cluster.application_prometheus&.installed? }
-  end
-
-  def client_from_cluster(cluster)
-    cluster.application_prometheus.proxy_client
-  end
-
-  def rename_field(old_field, new_field)
-    -> (metrics) do
-      metrics[new_field] = metrics.delete(old_field)
-      metrics
-    end
-  end
-
   def synchronize_service_state!
     self.active = prometheus_installed? || manual_configuration?

lib/gitlab/prometheus/additional_metrics_parser.rb

 module Gitlab
   module Prometheus
     module AdditionalMetricsParser
+      CONFIG_ROOT = 'config/prometheus'.freeze
+      MUTEX = Mutex.new
       extend self
-      def load_groups_from_yaml
-        additional_metrics_raw.map(&method(:group_from_entry))
+      def load_groups_from_yaml(file_name = 'additional_metrics.yml')
+        yaml_metrics_raw(file_name).map(&method(:group_from_entry))
       end
       private
@@ -22,13 +24,20 @@ module Gitlab
         MetricGroup.new(entry).tap(&method(:validate!))
       end
-      def additional_metrics_raw
-        load_yaml_file&.map(&:deep_symbolize_keys).freeze
+      def yaml_metrics_raw(file_name)
+        load_yaml_file(file_name)&.map(&:deep_symbolize_keys).freeze
       end
-      def load_yaml_file
-        @loaded_yaml_file ||= YAML.load_file(Rails.root.join('config/prometheus/additional_metrics.yml'))
+      # rubocop:disable Gitlab/ModuleWithInstanceVariables
+      def load_yaml_file(file_name)
+        return YAML.load_file(Rails.root.join(CONFIG_ROOT, file_name)) if Rails.env.development?
+
+        MUTEX.synchronize do
+          @loaded_yaml_cache ||= {}
+          @loaded_yaml_cache[file_name] ||= YAML.load_file(Rails.root.join(CONFIG_ROOT, file_name))
+        end
       end
+      # rubocop:enable Gitlab/ModuleWithInstanceVariables
     end
   end
 end

lib/gitlab/prometheus/queries/additional_metrics_deployment_query.rb

@@ -4,7 +4,7 @@ module Gitlab
       class AdditionalMetricsDeploymentQuery < BaseQuery
         include QueryAdditionalMetrics
-        def query(environment_id, deployment_id)
+        def query(deployment_id)
           Deployment.find_by(id: deployment_id).try do |deployment|
             query_metrics(
               deployment.project,

lib/gitlab/prometheus/queries/base_query.rb

@@ -20,6 +20,10 @@ module Gitlab
         def query(*args)
           raise NotImplementedError
         end
+
+        def self.transform_reactive_result(result)
+          result
+        end
       end
     end
   end

lib/gitlab/prometheus/queries/deployment_query.rb

@@ -2,7 +2,7 @@ module Gitlab
   module Prometheus
     module Queries
       class DeploymentQuery < BaseQuery
-        def query(environment_id, deployment_id)
+        def query(deployment_id)
           Deployment.find_by(id: deployment_id).try do |deployment|
             environment_slug = deployment.environment.slug
@@ -25,6 +25,11 @@ module Gitlab
             }
           end
         end
+
+        def self.transform_reactive_result(result)
+          result[:metrics] = result.delete :data
+          result
+        end
       end
     end
   end

lib/gitlab/prometheus/queries/environment_query.rb

@@ -19,6 +19,11 @@ module Gitlab
             }
           end
         end
+
+        def self.transform_reactive_result(result)
+          result[:metrics] = result.delete :data
+          result
+        end
       end
     end
   end

lib/gitlab/prometheus/queries/matched_metrics_query.rb → lib/gitlab/prometheus/queries/matched_metric_query.rb

 module Gitlab
   module Prometheus
     module Queries
-      class MatchedMetricsQuery < BaseQuery
+      class MatchedMetricQuery < BaseQuery
         MAX_QUERY_ITEMS = 40.freeze
         def query

lib/gitlab/prometheus/queries/query_additional_metrics.rb

@@ -3,9 +3,16 @@ module Gitlab
     module Queries
       module QueryAdditionalMetrics
         def query_metrics(project, query_context)
+          matched_metrics(project).map(&query_group(query_context))
+            .select(&method(:group_with_any_metrics))
+        end
+
+        protected
+
+        def query_group(query_context)
           query_processor = method(:process_query).curry[query_context]
-          groups = matched_metrics(project).map do |group|
+          lambda do |group|
             metrics = group.metrics.map do |metric|
               {
                 title: metric.title,
@@ -21,8 +28,6 @@ module Gitlab
               metrics: metrics.select(&method(:metric_with_any_queries))
             }
           end
-
-          groups.select(&method(:group_with_any_metrics))
         end
         private
@@ -72,12 +77,17 @@ module Gitlab
         end
         def common_query_context(environment, timeframe_start:, timeframe_end:)
-          {
-            timeframe_start: timeframe_start,
-            timeframe_end: timeframe_end,
+          base_query_context(timeframe_start, timeframe_end).merge({
             ci_environment_slug: environment.slug,
             kube_namespace: environment.project.deployment_platform&.actual_namespace || '',
             environment_filter: %{container_name!="POD",environment="#{environment.slug}"}
+          })
+        end
+
+        def base_query_context(timeframe_start, timeframe_end)
+          {
+            timeframe_start: timeframe_start,
+            timeframe_end: timeframe_end
           }
         end
       end

lib/gitlab/prometheus_client.rb

@@ -57,7 +57,11 @@ module Gitlab
     rescue OpenSSL::SSL::SSLError
       raise PrometheusClient::Error, "#{rest_client.url} contains invalid SSL data"
     rescue RestClient::ExceptionWithResponse => ex
-      handle_exception_response(ex.response)
+      if ex.response
+        handle_exception_response(ex.response)
+      else
+        raise PrometheusClient::Error, "Network connection error"
+      end
     rescue RestClient::Exception
       raise PrometheusClient::Error, "Network connection error"
     end

spec/controllers/projects/deployments_controller_spec.rb

@@ -129,10 +129,10 @@ describe Projects::DeploymentsController do
     end
     context 'when metrics are enabled' do
-      let(:prometheus_service) { double('prometheus_service') }
+      let(:prometheus_adapter) { double('prometheus_adapter', can_query?: true) }
       before do
-        allow(deployment.project).to receive(:prometheus_service).and_return(prometheus_service)
+        allow(deployment).to receive(:prometheus_adapter).and_return(prometheus_adapter)
       end
       context 'when environment has no metrics' do