Remove healthchecks from prometheus endpoint

app/services/metrics_service.rb

 require 'prometheus/client/formats/text'
 
 class MetricsService
-  CHECKS = [
-    Gitlab::HealthChecks::DbCheck,
-    Gitlab::HealthChecks::Redis::RedisCheck,
-    Gitlab::HealthChecks::Redis::CacheCheck,
-    Gitlab::HealthChecks::Redis::QueuesCheck,
-    Gitlab::HealthChecks::Redis::SharedStateCheck,
-    Gitlab::HealthChecks::GitalyCheck
-  ].freeze
-
   def prometheus_metrics_text
     Prometheus::Client::Formats::Text.marshal_multiprocess(multiprocess_metrics_path)
   end
 
-  def health_metrics_text
-    metrics = CHECKS.flat_map(&:metrics)
-
-    formatter.marshal(metrics)
-  end
-
   def metrics_text
-    prometheus_metrics_text.concat(health_metrics_text)
+    prometheus_metrics_text
   end
 
   private
 
-  def formatter
-    @formatter ||= Gitlab::HealthChecks::PrometheusTextFormat.new
-  end
-
   def multiprocess_metrics_path
     ::Prometheus::Client.configuration.multiprocess_files_dir
   end

changelogs/unreleased/an-no-healthcheck-until-brooklyn.yml

+---
+title: Remove healthchecks from prometheus endpoint
+merge_request: 20565
+author:
+type: fixed

spec/controllers/metrics_controller_spec.rb

@@ -15,55 +15,16 @@ describe MetricsController do
     allow(Prometheus::Client.configuration).to receive(:multiprocess_files_dir).and_return(metrics_multiproc_dir)
     allow(Gitlab::Metrics).to receive(:prometheus_metrics_enabled?).and_return(true)
     allow(Settings.monitoring).to receive(:ip_whitelist).and_return([whitelisted_ip, whitelisted_ip_range])
+    allow_any_instance_of(MetricsService).to receive(:metrics_text).and_return("prometheus_counter 1")
   end
 
   describe '#index' do
     shared_examples_for 'endpoint providing metrics' do
-      it 'returns DB ping metrics' do
+      it 'returns prometheus metrics' do
         get :index
 
-        expect(response.body).to match(/^db_ping_timeout 0$/)
-        expect(response.body).to match(/^db_ping_success 1$/)
-        expect(response.body).to match(/^db_ping_latency_seconds [0-9\.]+$/)
-      end
-
-      it 'returns Redis ping metrics' do
-        get :index
-
-        expect(response.body).to match(/^redis_ping_timeout 0$/)
-        expect(response.body).to match(/^redis_ping_success 1$/)
-        expect(response.body).to match(/^redis_ping_latency_seconds [0-9\.]+$/)
-      end
-
-      it 'returns Caching ping metrics' do
-        get :index
-
-        expect(response.body).to match(/^redis_cache_ping_timeout 0$/)
-        expect(response.body).to match(/^redis_cache_ping_success 1$/)
-        expect(response.body).to match(/^redis_cache_ping_latency_seconds [0-9\.]+$/)
-      end
-
-      it 'returns Queues ping metrics' do
-        get :index
-
-        expect(response.body).to match(/^redis_queues_ping_timeout 0$/)
-        expect(response.body).to match(/^redis_queues_ping_success 1$/)
-        expect(response.body).to match(/^redis_queues_ping_latency_seconds [0-9\.]+$/)
-      end
-
-      it 'returns SharedState ping metrics' do
-        get :index
-
-        expect(response.body).to match(/^redis_shared_state_ping_timeout 0$/)
-        expect(response.body).to match(/^redis_shared_state_ping_success 1$/)
-        expect(response.body).to match(/^redis_shared_state_ping_latency_seconds [0-9\.]+$/)
-      end
-
-      it 'returns Gitaly metrics' do
-        get :index
-
-        expect(response.body).to match(/^gitaly_health_check_success{shard="default"} 1$/)
-        expect(response.body).to match(/^gitaly_health_check_latency_seconds{shard="default"} [0-9\.]+$/)
+        expect(response.status).to eq(200)
+        expect(response.body).to match(/^prometheus_counter 1$/)
       end
 
       context 'prometheus metrics are disabled' do
@@ -101,7 +62,7 @@ describe MetricsController do
         allow(Gitlab::RequestContext).to receive(:client_ip).and_return(not_whitelisted_ip)
       end
 
-      it 'returns proper response' do
+      it 'returns the expected error response' do
         get :index
 
         expect(response.status).to eq(404)