Make queries not die when underlying data cannot be found

lib/gitlab/prometheus/queries/additional_metrics_deployment_query.rb

@@ -5,7 +5,7 @@ module Gitlab
         include QueryAdditionalMetrics
 
         def query(deployment_id)
-          deployment = Deployment.find_by(id: 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}"},
@@ -18,4 +18,5 @@ module Gitlab
         end
       end
     end
+  end
 end

lib/gitlab/prometheus/queries/additional_metrics_environment_query.rb

@@ -5,7 +5,7 @@ module Gitlab
         include QueryAdditionalMetrics
 
         def query(environment_id)
-          environment = Environment.find_by(id: 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}"},
@@ -18,4 +18,5 @@ module Gitlab
         end
       end
     end
+  end
 end

lib/gitlab/prometheus/queries/deployment_query.rb

@@ -3,7 +3,7 @@ module Gitlab
     module Queries
       class DeploymentQuery < BaseQuery
         def query(deployment_id)
-          deployment = Deployment.find_by(id: deployment_id)
+          Deployment.find_by(id: deployment_id).try do |deployment|
             environment_slug = deployment.environment.slug
 
             memory_query = raw_memory_usage_query(environment_slug)
@@ -27,4 +27,5 @@ module Gitlab
         end
       end
     end
+  end
 end

lib/gitlab/prometheus/queries/environment_query.rb

@@ -3,7 +3,7 @@ module Gitlab
     module Queries
       class EnvironmentQuery < BaseQuery
         def query(environment_id)
-          environment = Environment.find_by(id: 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
@@ -21,4 +21,5 @@ module Gitlab
         end
       end
     end
+  end
 end

spec/controllers/projects/deployments_controller_spec.rb

@@ -141,7 +141,7 @@ describe Projects::DeploymentsController do
         end
 
         it 'returns a empty response 204 response' do
-          get :additional_metrics, deployment_params(id: deployment.id)
+          get :additional_metrics, deployment_params(id: deployment.id, format: :json)
           expect(response).to have_http_status(204)
           expect(response.body).to eq('')
         end
@@ -161,7 +161,7 @@ describe Projects::DeploymentsController do
         end
 
         it 'returns a metrics JSON document' do
-          get :additional_metrics, deployment_params(id: deployment.id)
+          get :additional_metrics, deployment_params(id: deployment.id, format: :json)
 
           expect(response).to be_ok
           expect(json_response['success']).to be(true)