Squashed commit of the following:

commit 22e1cb8f4b98f71d21026f69aa3e68d79946d6ae
Merge: 766a42a9639 e966c6aea25
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 6844a2df873
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

5 files changed, 224 insertions, 230 deletions

diff --git a/spec/models/clusters/applications/prometheus_spec.rb b/spec/models/clusters/applications/prometheus_spec.rb
index 01037919530..959fb338672 100644
--- a/spec/models/clusters/applications/prometheus_spec.rb
+++ b/spec/models/clusters/applications/prometheus_spec.rb
@@ -32,11 +32,11 @@ describe Clusters::Applications::Prometheus do
     end
   end
 
-  describe '#proxy_client' do
+  describe '#prometheus_client' do
     context 'cluster is nil' do
       it 'returns nil' do
         expect(subject.cluster).to be_nil
-        expect(subject.proxy_client).to be_nil
+        expect(subject.prometheus_client).to be_nil
       end
     end
 
@@ -45,7 +45,7 @@ describe Clusters::Applications::Prometheus do
       subject { create(:clusters_applications_prometheus, cluster: cluster) }
 
       it 'returns nil' do
-        expect(subject.proxy_client).to be_nil
+        expect(subject.prometheus_client).to be_nil
       end
     end
 
@@ -73,15 +73,15 @@ describe Clusters::Applications::Prometheus do
       end
 
       it 'creates proxy prometheus rest client' do
-        expect(subject.proxy_client).to be_instance_of(RestClient::Resource)
+        expect(subject.prometheus_client).to be_instance_of(RestClient::Resource)
       end
 
       it 'creates proper url' do
-        expect(subject.proxy_client.url).to eq('http://example.com/api/v1/proxy/namespaces/gitlab-managed-apps/service/prometheus-prometheus-server:80')
+        expect(subject.prometheus_client.url).to eq('http://example.com/api/v1/proxy/namespaces/gitlab-managed-apps/service/prometheus-prometheus-server:80')
       end
 
       it 'copies options and headers from kube client to proxy client' do
-        expect(subject.proxy_client.options).to eq(kube_client.rest_client.options.merge(headers: kube_client.headers))
+        expect(subject.prometheus_client.options).to eq(kube_client.rest_client.options.merge(headers: kube_client.headers))
       end
     end
   end
diff --git a/spec/models/concerns/prometheus_adapter_spec.rb b/spec/models/concerns/prometheus_adapter_spec.rb
new file mode 100644
index 00000000000..f4b9c57e71a
--- /dev/null
+++ b/spec/models/concerns/prometheus_adapter_spec.rb
@@ -0,0 +1,121 @@
+require 'spec_helper'
+
+describe PrometheusAdapter, :use_clean_rails_memory_store_caching do
+  include PrometheusHelpers
+  include ReactiveCachingHelpers
+
+  class TestClass
+    include PrometheusAdapter
+  end
+
+  let(:project) { create(:prometheus_project) }
+  let(:service) { project.prometheus_service }
+
+  let(:described_class) { TestClass }
+  let(:environment_query) { Gitlab::Prometheus::Queries::EnvironmentQuery }
+
+  describe '#query' do
+    describe 'environment' do
+      let(:environment) { build_stubbed(:environment, slug: 'env-slug') }
+
+      around do |example|
+        Timecop.freeze { example.run }
+      end
+
+      context 'with valid data' do
+        subject { service.query(:environment, environment) }
+
+        before do
+          stub_reactive_cache(service, prometheus_data, environment_query, environment.id)
+        end
+
+        it 'returns reactive data' do
+          is_expected.to eq(prometheus_metrics_data)
+        end
+      end
+    end
+
+    describe 'matched_metrics' do
+      let(:matched_metrics_query) { Gitlab::Prometheus::Queries::MatchedMetricQuery }
+      let(:prometheus_client_wrapper) { double(:prometheus_client_wrapper, label_values: nil) }
+
+      context 'with valid data' do
+        subject { service.query(:matched_metrics) }
+
+        before do
+          allow(service).to receive(:prometheus_client_wrapper).and_return(prometheus_client_wrapper)
+          synchronous_reactive_cache(service)
+        end
+
+        it 'returns reactive data' do
+          expect(subject[:success]).to be_truthy
+          expect(subject[:data]).to eq([])
+        end
+      end
+    end
+
+    describe 'deployment' do
+      let(:deployment) { build_stubbed(:deployment) }
+      let(:deployment_query) { Gitlab::Prometheus::Queries::DeploymentQuery }
+
+      around do |example|
+        Timecop.freeze { example.run }
+      end
+
+      context 'with valid data' do
+        subject { service.query(:deployment, deployment) }
+
+        before do
+          stub_reactive_cache(service, prometheus_data, deployment_query, deployment.id)
+        end
+
+        it 'returns reactive data' do
+          expect(subject).to eq(prometheus_metrics_data)
+        end
+      end
+    end
+  end
+
+  describe '#calculate_reactive_cache' do
+    let(:environment) { create(:environment, slug: 'env-slug') }
+    before do
+      service.manual_configuration = true
+      service.active = true
+    end
+
+    subject do
+      service.calculate_reactive_cache(environment_query.name, environment.id)
+    end
+
+    around do |example|
+      Timecop.freeze { example.run }
+    end
+
+    context 'when service is inactive' do
+      before do
+        service.active = false
+      end
+
+      it { is_expected.to be_nil }
+    end
+
+    context 'when Prometheus responds with valid data' do
+      before do
+        stub_all_prometheus_requests(environment.slug)
+      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|
+      context "when Prometheus responds with #{status}" do
+        before do
+          stub_all_prometheus_requests(environment.slug, status: status, body: "QUERY FAILED!")
+        end
+
+        it { is_expected.to eq(success: false, result: %(#{status} - "QUERY FAILED!")) }
+      end
+    end
+  end
+end
diff --git a/spec/models/deployment_spec.rb b/spec/models/deployment_spec.rb
index ba8aa13d5ad..ac30cd27e0c 100644
--- a/spec/models/deployment_spec.rb
+++ b/spec/models/deployment_spec.rb
@@ -64,6 +64,7 @@ describe Deployment do
 
   describe '#metrics' do
     let(:deployment) { create(:deployment) }
+    let(:prometheus_adapter) { double('prometheus_adapter', can_query?: true) }
 
     subject { deployment.metrics }
 
@@ -76,17 +77,16 @@ describe Deployment do
         {
           success: true,
           metrics: {},
-          last_update: 42,
-          deployment_time: 1494408956
+          last_update: 42
         }
       end
 
       before do
-        allow(deployment.project).to receive_message_chain(:monitoring_service, :deployment_metrics)
-                                       .with(any_args).and_return(simple_metrics)
+        allow(deployment).to receive(:prometheus_adapter).and_return(prometheus_adapter)
+        allow(prometheus_adapter).to receive(:query).with(:deployment, deployment).and_return(simple_metrics)
       end
 
-      it { is_expected.to eq(simple_metrics) }
+      it { is_expected.to eq(simple_metrics.merge({ deployment_time: deployment.created_at.to_i })) }
     end
   end
 
@@ -109,11 +109,11 @@ describe Deployment do
         }
       end
 
-      let(:prometheus_service) { double('prometheus_service') }
+      let(:prometheus_adapter) { double('prometheus_adapter', can_query?: true) }
 
       before do
-        allow(project).to receive(:prometheus_service).and_return(prometheus_service)
-        allow(prometheus_service).to receive(:additional_deployment_metrics).and_return(simple_metrics)
+        allow(deployment).to receive(:prometheus_adapter).and_return(prometheus_adapter)
+        allow(prometheus_adapter).to receive(:query).with(:additional_metrics_deployment, deployment).and_return(simple_metrics)
       end
 
       it { is_expected.to eq(simple_metrics.merge({ deployment_time: deployment.created_at.to_i })) }
diff --git a/spec/models/environment_spec.rb b/spec/models/environment_spec.rb
index 6f24a039998..1049e47d25d 100644
--- a/spec/models/environment_spec.rb
+++ b/spec/models/environment_spec.rb
@@ -452,8 +452,8 @@ describe Environment do
       end
 
       it 'returns the metrics from the deployment service' do
-        expect(project.monitoring_service)
-          .to receive(:environment_metrics).with(environment)
+        expect(environment.prometheus_adapter)
+          .to receive(:query).with(:environment, environment)
           .and_return(:fake_metrics)
 
         is_expected.to eq(:fake_metrics)
@@ -508,12 +508,12 @@ describe Environment do
 
     context 'when the environment has additional metrics' do
       before do
-        allow(environment).to receive(:has_additional_metrics?).and_return(true)
+        allow(environment).to receive(:has_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)
+        expect(environment.prometheus_adapter).to receive(:query)
+                                                .with(:additional_metrics_environment, environment)
                                                 .and_return(:fake_metrics)
 
         is_expected.to eq(:fake_metrics)
@@ -522,46 +522,13 @@ describe Environment do
 
     context 'when the environment does not have metrics' do
       before do
-        allow(environment).to receive(:has_additional_metrics?).and_return(false)
+        allow(environment).to receive(:has_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
@@ -654,4 +621,77 @@ describe Environment do
       end
     end
   end
+
+  describe '#prometheus_adapter' do
+    let!(:cluster_for_all) { create(:cluster, environment_scope: '*', projects: [project]) }
+    let!(:cluster_for_dev) { create(:cluster, environment_scope: 'dev', projects: [project]) }
+
+    let!(:prometheus_for_dev) { create(:clusters_applications_prometheus, :installed, cluster: cluster_for_dev) }
+
+    context 'prometheus service can execute queries' do
+      let(:prometheus_service) { double(:prometheus_service, can_query?: true) }
+
+      before do
+        allow(environment.project).to receive(:find_or_initialize_service).with('prometheus').and_return prometheus_service
+      end
+
+      it 'return prometheus service as prometheus adapter' do
+        expect(environment.prometheus_adapter).to eq(prometheus_service)
+      end
+    end
+
+    context "prometheus service can't execute queries" do
+      let(:prometheus_service) { double(:prometheus_service, can_query?: false) }
+
+      context 'with cluster for all environments with prometheus installed' do
+        let!(:prometheus_for_all) { create(:clusters_applications_prometheus, :installed, cluster: cluster_for_all) }
+
+        context 'without environment supplied' do
+          it 'returns application handling all environments' do
+            expect(environment.prometheus_adapter).to eq(prometheus_for_all)
+          end
+        end
+
+        context 'with dev environment supplied' do
+          let!(:environment) { create(:environment, project: project, name: 'dev') }
+
+          it 'returns dev cluster prometheus application' do
+            expect(environment.prometheus_adapter).to eq(prometheus_for_dev)
+          end
+        end
+
+        context 'with prod environment supplied' do
+          let!(:environment) { create(:environment, project: project, name: 'prod') }
+
+          it 'returns application handling all environments' do
+            expect(environment.prometheus_adapter).to eq(prometheus_for_all)
+          end
+        end
+      end
+
+      context 'with cluster for all environments without prometheus installed' do
+        context 'without environment supplied' do
+          it 'returns nil' do
+            expect(environment.prometheus_adapter).to be_nil
+          end
+        end
+
+        context 'with dev environment supplied' do
+          let!(:environment) { create(:environment, project: project, name: 'dev') }
+
+          it 'returns dev cluster prometheus application' do
+            expect(environment.prometheus_adapter).to eq(prometheus_for_dev)
+          end
+        end
+
+        context 'with prod environment supplied' do
+          let!(:environment) { create(:environment, project: project, name: 'prod') }
+
+          it 'returns nil' do
+            expect(environment.prometheus_adapter).to be_nil
+          end
+        end
+      end
+    end
+  end
 end
diff --git a/spec/models/project_services/prometheus_service_spec.rb b/spec/models/project_services/prometheus_service_spec.rb
index 6693e5783a5..6a4bdb47105 100644
--- a/spec/models/project_services/prometheus_service_spec.rb
+++ b/spec/models/project_services/prometheus_service_spec.rb
@@ -6,7 +6,6 @@ describe PrometheusService, :use_clean_rails_memory_store_caching do
 
   let(:project) { create(:prometheus_project) }
   let(:service) { project.prometheus_service }
-  let(:environment_query) { Gitlab::Prometheus::Queries::EnvironmentQuery }
 
   describe "Associations" do
     it { is_expected.to belong_to :project }
@@ -55,197 +54,31 @@ describe PrometheusService, :use_clean_rails_memory_store_caching do
     end
   end
 
-  describe '#environment_metrics' do
-    let(:environment) { build_stubbed(:environment, slug: 'env-slug') }
-
-    around do |example|
-      Timecop.freeze { example.run }
-    end
-
-    context 'with valid data' do
-      subject { service.environment_metrics(environment) }
-
-      before do
-        stub_reactive_cache(service, prometheus_data, environment_query, environment.id)
-      end
-
-      it 'returns reactive data' do
-        is_expected.to eq(prometheus_metrics_data)
-      end
-    end
-  end
-
-  describe '#matched_metrics' do
-    let(:matched_metrics_query) { Gitlab::Prometheus::Queries::MatchedMetricsQuery }
-    let(:client) { double(:client, label_values: nil) }
-
-    context 'with valid data' do
-      subject { service.matched_metrics }
-
-      before do
-        allow(service).to receive(:client).and_return(client)
-        synchronous_reactive_cache(service)
-      end
-
-      it 'returns reactive data' do
-        expect(subject[:success]).to be_truthy
-        expect(subject[:data]).to eq([])
-      end
-    end
-  end
-
-  describe '#deployment_metrics' do
-    let(:deployment) { build_stubbed(:deployment) }
-    let(:deployment_query) { Gitlab::Prometheus::Queries::DeploymentQuery }
-
-    around do |example|
-      Timecop.freeze { example.run }
-    end
-
-    context 'with valid data' do
-      subject { service.deployment_metrics(deployment) }
-      let(:fake_deployment_time) { 10 }
-
-      before do
-        stub_reactive_cache(service, prometheus_data, deployment_query, deployment.environment.id, deployment.id)
-      end
-
-      it 'returns reactive data' do
-        expect(deployment).to receive(:created_at).and_return(fake_deployment_time)
-
-        expect(subject).to eq(prometheus_metrics_data.merge(deployment_time: fake_deployment_time))
-      end
-    end
-  end
-
-  describe '#calculate_reactive_cache' do
-    let(:environment) { create(:environment, slug: 'env-slug') }
-    before do
-      service.manual_configuration = true
-      service.active = true
-    end
-
-    subject do
-      service.calculate_reactive_cache(environment_query.name, environment.id)
-    end
-
-    around do |example|
-      Timecop.freeze { example.run }
-    end
-
-    context 'when service is inactive' do
-      before do
-        service.active = false
-      end
-
-      it { is_expected.to be_nil }
-    end
-
-    context 'when Prometheus responds with valid data' do
-      before do
-        stub_all_prometheus_requests(environment.slug)
-      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|
-      context "when Prometheus responds with #{status}" do
-        before do
-          stub_all_prometheus_requests(environment.slug, status: status, body: "QUERY FAILED!")
-        end
-
-        it { is_expected.to eq(success: false, result: %(#{status} - "QUERY FAILED!")) }
-      end
-    end
-  end
-
-  describe '#client' do
+  describe '#prometheus_client' do
     context 'manual configuration is enabled' do
       let(:api_url) { 'http://some_url' }
+
       before do
+        subject.active = true
         subject.manual_configuration = true
         subject.api_url = api_url
       end
 
-      it 'returns simple rest client from api_url' do
-        expect(subject.client).to be_instance_of(Gitlab::PrometheusClient)
-        expect(subject.client.rest_client.url).to eq(api_url)
+      it 'returns rest client from api_url' do
+        expect(subject.prometheus_client.url).to eq(api_url)
       end
     end
 
     context 'manual configuration is disabled' do
-      let!(:cluster_for_all) { create(:cluster, environment_scope: '*', projects: [project]) }
-      let!(:cluster_for_dev) { create(:cluster, environment_scope: 'dev', projects: [project]) }
-
-      let!(:prometheus_for_dev) { create(:clusters_applications_prometheus, :installed, cluster: cluster_for_dev) }
-      let(:proxy_client) { double('proxy_client') }
+      let(:api_url) { 'http://some_url' }
 
       before do
-        service.manual_configuration = false
-      end
-
-      context 'with cluster for all environments with prometheus installed' do
-        let!(:prometheus_for_all) { create(:clusters_applications_prometheus, :installed, cluster: cluster_for_all) }
-
-        context 'without environment supplied' do
-          it 'returns client handling all environments' do
-            expect(service).to receive(:client_from_cluster).with(cluster_for_all).and_return(proxy_client).twice
-
-            expect(service.client).to be_instance_of(Gitlab::PrometheusClient)
-            expect(service.client.rest_client).to eq(proxy_client)
-          end
-        end
-
-        context 'with dev environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'dev') }
-
-          it 'returns dev cluster client' do
-            expect(service).to receive(:client_from_cluster).with(cluster_for_dev).and_return(proxy_client).twice
-
-            expect(service.client(environment.id)).to be_instance_of(Gitlab::PrometheusClient)
-            expect(service.client(environment.id).rest_client).to eq(proxy_client)
-          end
-        end
-
-        context 'with prod environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'prod') }
-
-          it 'returns dev cluster client' do
-            expect(service).to receive(:client_from_cluster).with(cluster_for_all).and_return(proxy_client).twice
-
-            expect(service.client(environment.id)).to be_instance_of(Gitlab::PrometheusClient)
-            expect(service.client(environment.id).rest_client).to eq(proxy_client)
-          end
-        end
+        subject.manual_configuration = false
+        subject.api_url = api_url
       end
 
-      context 'with cluster for all environments without prometheus installed' do
-        context 'without environment supplied' do
-          it 'raises PrometheusClient::Error because cluster was not found' do
-            expect { service.client }.to raise_error(Gitlab::PrometheusClient::Error, /couldn't find cluster with Prometheus installed/)
-          end
-        end
-
-        context 'with dev environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'dev') }
-
-          it 'returns dev cluster client' do
-            expect(service).to receive(:client_from_cluster).with(cluster_for_dev).and_return(proxy_client).twice
-
-            expect(service.client(environment.id)).to be_instance_of(Gitlab::PrometheusClient)
-            expect(service.client(environment.id).rest_client).to eq(proxy_client)
-          end
-        end
-
-        context 'with prod environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'prod') }
-
-          it 'raises PrometheusClient::Error because cluster was not found' do
-            expect { service.client }.to raise_error(Gitlab::PrometheusClient::Error, /couldn't find cluster with Prometheus installed/)
-          end
-        end
+      it 'no client provided' do
+        expect(subject.prometheus_client).to be_nil
       end
     end
   end