Use separate Kubernetes namespaces per environment

Kubernetes deployments on new clusters will now have
a separate namespace per project environment, instead
of sharing a single namespace for the project.

Behaviour of existing clusters is unchanged.

All new functionality is controlled by the
:kubernetes_namespace_per_environment feature flag,
which is safe to enable/disable at any time.

2 files changed, 66 insertions, 5 deletions

diff --git a/spec/services/clusters/build_kubernetes_namespace_service_spec.rb b/spec/services/clusters/build_kubernetes_namespace_service_spec.rb
new file mode 100644
index 00000000000..36c05469542
--- /dev/null
+++ b/spec/services/clusters/build_kubernetes_namespace_service_spec.rb
@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Clusters::BuildKubernetesNamespaceService do
+  let(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+  let(:environment) { create(:environment) }
+  let(:project) { environment.project }
+
+  let(:namespace_generator) { double(from_environment_slug: namespace) }
+  let(:namespace) { 'namespace' }
+
+  subject { described_class.new(cluster, environment: environment).execute }
+
+  before do
+    allow(Gitlab::Kubernetes::DefaultNamespace).to receive(:new).and_return(namespace_generator)
+  end
+
+  shared_examples 'shared attributes' do
+    it 'initializes a new namespace and sets default values' do
+      expect(subject).to be_new_record
+      expect(subject.cluster).to eq cluster
+      expect(subject.project).to eq project
+      expect(subject.namespace).to eq namespace
+      expect(subject.service_account_name).to eq "#{namespace}-service-account"
+    end
+  end
+
+  include_examples 'shared attributes'
+
+  it 'sets cluster_project and environment' do
+    expect(subject.cluster_project).to eq cluster.cluster_project
+    expect(subject.environment).to eq environment
+  end
+
+  context 'namespace per environment is disabled' do
+    let(:cluster) { create(:cluster, :project, :provided_by_gcp, :namespace_per_environment_disabled) }
+
+    include_examples 'shared attributes'
+
+    it 'does not set environment' do
+      expect(subject.cluster_project).to eq cluster.cluster_project
+      expect(subject.environment).to be_nil
+    end
+  end
+
+  context 'group cluster' do
+    let(:cluster) { create(:cluster, :group, :provided_by_gcp) }
+
+    include_examples 'shared attributes'
+
+    it 'does not set cluster_project' do
+      expect(subject.cluster_project).to be_nil
+      expect(subject.environment).to eq environment
+    end
+  end
+end
diff --git a/spec/services/clusters/gcp/kubernetes/create_or_update_namespace_service_spec.rb b/spec/services/clusters/gcp/kubernetes/create_or_update_namespace_service_spec.rb
index 44407ae2793..e44cc3f5a78 100644
--- a/spec/services/clusters/gcp/kubernetes/create_or_update_namespace_service_spec.rb
+++ b/spec/services/clusters/gcp/kubernetes/create_or_update_namespace_service_spec.rb
@@ -9,8 +9,9 @@ describe Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService, '#execute' d
   let(:platform) { cluster.platform }
   let(:api_url) { 'https://kubernetes.example.com' }
   let(:project) { cluster.project }
+  let(:environment) { create(:environment, project: project) }
   let(:cluster_project) { cluster.cluster_project }
-  let(:namespace) { "#{project.path}-#{project.id}" }
+  let(:namespace) { "#{project.name}-#{project.id}-#{environment.slug}" }
 
   subject do
     described_class.new(
@@ -79,7 +80,8 @@ describe Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService, '#execute' d
       let(:kubernetes_namespace) do
         build(:cluster_kubernetes_namespace,
               cluster: cluster,
-              project: project)
+              project: project,
+              environment: environment)
       end
 
       it_behaves_like 'successful creation of kubernetes namespace'
@@ -92,20 +94,22 @@ describe Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService, '#execute' d
         build(:cluster_kubernetes_namespace,
               cluster: cluster,
               project: cluster_project.project,
-              cluster_project: cluster_project)
+              cluster_project: cluster_project,
+              environment: environment)
       end
 
       it_behaves_like 'successful creation of kubernetes namespace'
     end
 
     context 'when there is a Kubernetes Namespace associated' do
-      let(:namespace) { 'new-namespace' }
+      let(:namespace) { "new-namespace-#{environment.slug}" }
 
       let(:kubernetes_namespace) do
         create(:cluster_kubernetes_namespace,
                cluster: cluster,
                project: cluster_project.project,
-               cluster_project: cluster_project)
+               cluster_project: cluster_project,
+               environment: environment)
       end
 
       before do