Remove the pod_logs_reactive_cache feature flag

Now that the frontend polls the pod logs API, we can enable reactive
caching for the API, which was behind the feature flag.

changelogs/unreleased/12819-remove-feature-flag.yml

+---
+title: Fix pod logs failure when pod contains more than 1 container
+merge_request: 18574
+author:
+type: fixed

ee/app/models/ee/clusters/platforms/kubernetes.rb

@@ -27,17 +27,13 @@ module EE
         end
 
         def read_pod_logs(pod_name, namespace, container: nil)
-          if ::Feature.enabled?(:pod_logs_reactive_cache)
-            with_reactive_cache(
-              'get_pod_log',
-              'pod_name' => pod_name,
-              'namespace' => namespace,
-              'container' => container
-            ) do |result|
-              result
-            end
-          else
-            pod_logs(pod_name, namespace, container: container)
+          with_reactive_cache(
+            'get_pod_log',
+            'pod_name' => pod_name,
+            'namespace' => namespace,
+            'container' => container
+          ) do |result|
+            result
           end
         end
 
@@ -59,13 +55,11 @@ module EE
         private
 
         def pod_logs(pod_name, namespace, container: nil)
-          handle_exceptions(_('Pod not found')) do
-            logs = kubeclient.get_pod_log(
-              pod_name, namespace, container: container, tail_lines: LOGS_LIMIT
-            ).body
+          logs = kubeclient.get_pod_log(
+            pod_name, namespace, container: container, tail_lines: LOGS_LIMIT
+          ).body
 
-            { logs: logs, status: :success }
-          end
+          { logs: logs, status: :success }
         end
 
         def handle_exceptions(resource_not_found_error_message, &block)

ee/spec/features/projects/environments_pod_logs_spec.rb

@@ -16,21 +16,18 @@ describe 'Environment > Pod Logs', :js do
   before do
     stub_licensed_features(pod_logs: true)
 
-    # We're setting this feature flag to false since the FE does not support it
-    # as yet.
-    stub_feature_flags(pod_logs_reactive_cache: false)
-
     create(:cluster, :provided_by_gcp, environment_scope: '*', projects: [project])
     create(:deployment, :success, environment: environment)
 
-    stub_kubeclient_logs(pod_name, environment.deployment_namespace, container: nil)
+    stub_kubeclient_pod_details(pod_name, environment.deployment_namespace)
+    stub_kubeclient_logs(pod_name, environment.deployment_namespace, container: 'container-0')
 
     allow_any_instance_of(EE::Environment).to receive(:pod_names).and_return(pod_names)
 
     sign_in(project.owner)
   end
 
-  context 'with logs' do
+  context 'with logs', :use_clean_rails_memory_store_caching do
     it "shows pod logs" do
       visit logs_project_environment_path(environment.project, environment, pod_name: pod_name)
 

ee/spec/models/ee/clusters/platforms/kubernetes_spec.rb

@@ -150,7 +150,11 @@ describe Clusters::Platforms::Kubernetes do
       end
     end
 
-    shared_examples 'k8s responses' do
+    context 'with reactive cache' do
+      before do
+        synchronous_reactive_cache(service)
+      end
+
       context 'when kubernetes responds with valid logs' do
         before do
           stub_kubeclient_logs(pod_name, namespace, container: container)
@@ -201,34 +205,6 @@ describe Clusters::Platforms::Kubernetes do
 
         it_behaves_like 'resource not found error', 'Pod not found'
       end
-    end
-
-    context 'without pod_logs_reactive_cache feature flag' do
-      before do
-        stub_feature_flags(pod_logs_reactive_cache: false)
-      end
-
-      it_behaves_like 'k8s responses'
-
-      context 'when container name is not specified' do
-        subject { service.read_pod_logs(pod_name, namespace) }
-
-        before do
-          stub_kubeclient_logs(pod_name, namespace, container: nil)
-        end
-
-        include_examples 'successful log request'
-      end
-    end
-
-    context 'with pod_logs_reactive_cache feature flag' do
-      before do
-        stub_feature_flags(pod_logs_reactive_cache: true)
-
-        synchronous_reactive_cache(service)
-      end
-
-      it_behaves_like 'k8s responses'
 
       context 'when container name is not specified' do
         subject { service.read_pod_logs(pod_name, namespace) }
@@ -247,10 +223,6 @@ describe Clusters::Platforms::Kubernetes do
         ['get_pod_log', { 'pod_name' => pod_name, 'namespace' => namespace, 'container' => container }]
       end
 
-      before do
-        stub_feature_flags(pod_logs_reactive_cache: true)
-      end
-
       context 'result is cacheable' do
         before do
           stub_kubeclient_logs(pod_name, namespace, container: container)