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.

3 files changed, 153 insertions, 19 deletions

diff --git a/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb b/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb
index d88a2097ba2..775550f2acc 100644
--- a/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb
+++ b/spec/lib/gitlab/ci/build/prerequisite/kubernetes_namespace_spec.rb
@@ -3,9 +3,9 @@
 require 'spec_helper'
 
 describe Gitlab::Ci::Build::Prerequisite::KubernetesNamespace do
-  let(:build) { create(:ci_build) }
-
   describe '#unmet?' do
+    let(:build) { create(:ci_build) }
+
     subject { described_class.new(build).unmet? }
 
     context 'build has no deployment' do
@@ -18,7 +18,6 @@ describe Gitlab::Ci::Build::Prerequisite::KubernetesNamespace do
 
     context 'build has a deployment' do
       let!(:deployment) { create(:deployment, deployable: build, cluster: cluster) }
-      let(:cluster) { nil }
 
       context 'and a cluster to deploy to' do
         let(:cluster) { create(:cluster, :group) }
@@ -32,12 +31,17 @@ describe Gitlab::Ci::Build::Prerequisite::KubernetesNamespace do
         end
 
         context 'and a namespace is already created for this project' do
-          let!(:kubernetes_namespace) { create(:cluster_kubernetes_namespace, :with_token, cluster: cluster, project: build.project) }
+          let(:kubernetes_namespace) { instance_double(Clusters::KubernetesNamespace, service_account_token: 'token') }
+
+          before do
+            allow(Clusters::KubernetesNamespaceFinder).to receive(:new)
+              .and_return(double(execute: kubernetes_namespace))
+          end
 
           it { is_expected.to be_falsey }
 
           context 'and the service_account_token is blank' do
-            let!(:kubernetes_namespace) { create(:cluster_kubernetes_namespace, :without_token, cluster: cluster, project: build.project) }
+            let(:kubernetes_namespace) { instance_double(Clusters::KubernetesNamespace, service_account_token: nil) }
 
             it { is_expected.to be_truthy }
           end
@@ -45,34 +49,79 @@ describe Gitlab::Ci::Build::Prerequisite::KubernetesNamespace do
       end
 
       context 'and no cluster to deploy to' do
+        let(:cluster) { nil }
+
         it { is_expected.to be_falsey }
       end
     end
   end
 
   describe '#complete!' do
-    let!(:deployment) { create(:deployment, deployable: build, cluster: cluster) }
-    let(:service) { double(execute: true) }
-    let(:cluster) { nil }
+    let(:build) { create(:ci_build) }
+    let(:prerequisite) { described_class.new(build) }
 
-    subject { described_class.new(build).complete! }
+    subject { prerequisite.complete! }
 
     context 'completion is required' do
       let(:cluster) { create(:cluster, :group) }
+      let(:deployment) { create(:deployment, cluster: cluster) }
+      let(:service) { double(execute: true) }
+      let(:kubernetes_namespace) { double }
+
+      before do
+        allow(prerequisite).to receive(:unmet?).and_return(true)
+        allow(build).to receive(:deployment).and_return(deployment)
+      end
+
+      context 'kubernetes namespace does not exist' do
+        let(:namespace_builder) { double(execute: kubernetes_namespace)}
 
-      it 'creates a kubernetes namespace' do
-        expect(Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService)
-          .to receive(:new)
-          .with(cluster: cluster, kubernetes_namespace: instance_of(Clusters::KubernetesNamespace))
-          .and_return(service)
+        before do
+          allow(Clusters::KubernetesNamespaceFinder).to receive(:new)
+            .and_return(double(execute: nil))
+        end
 
-        expect(service).to receive(:execute).once
+        it 'creates a namespace using a new record' do
+          expect(Clusters::BuildKubernetesNamespaceService)
+            .to receive(:new)
+            .with(cluster, environment: deployment.environment)
+            .and_return(namespace_builder)
 
-        subject
+          expect(Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService)
+            .to receive(:new)
+            .with(cluster: cluster, kubernetes_namespace: kubernetes_namespace)
+            .and_return(service)
+
+          expect(service).to receive(:execute).once
+
+          subject
+        end
+      end
+
+      context 'kubernetes namespace exists (but has no service_account_token)' do
+        before do
+          allow(Clusters::KubernetesNamespaceFinder).to receive(:new)
+            .and_return(double(execute: kubernetes_namespace))
+        end
+
+        it 'creates a namespace using the tokenless record' do
+          expect(Clusters::BuildKubernetesNamespaceService).not_to receive(:new)
+
+          expect(Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService)
+            .to receive(:new)
+            .with(cluster: cluster, kubernetes_namespace: kubernetes_namespace)
+            .and_return(service)
+
+          subject
+        end
       end
     end
 
     context 'completion is not required' do
+      before do
+        allow(prerequisite).to receive(:unmet?).and_return(false)
+      end
+
       it 'does not create a namespace' do
         expect(Clusters::Gcp::Kubernetes::CreateOrUpdateNamespaceService).not_to receive(:new)
 
diff --git a/spec/lib/gitlab/kubernetes/default_namespace_spec.rb b/spec/lib/gitlab/kubernetes/default_namespace_spec.rb
new file mode 100644
index 00000000000..1fda547f35c
--- /dev/null
+++ b/spec/lib/gitlab/kubernetes/default_namespace_spec.rb
@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Kubernetes::DefaultNamespace do
+  let(:generator) { described_class.new(cluster, project: environment.project) }
+
+  describe '#from_environment_name' do
+    let(:cluster) { create(:cluster) }
+    let(:environment) { create(:environment) }
+
+    subject { generator.from_environment_name(environment.name) }
+
+    it 'generates a slug and passes it to #from_environment_slug' do
+      expect(Gitlab::Slug::Environment).to receive(:new)
+        .with(environment.name)
+        .and_return(double(generate: environment.slug))
+
+      expect(generator).to receive(:from_environment_slug)
+        .with(environment.slug)
+        .and_return(:mock_namespace)
+
+      expect(subject).to eq :mock_namespace
+    end
+  end
+
+  describe '#from_environment_slug' do
+    let(:platform) { create(:cluster_platform_kubernetes, namespace: platform_namespace) }
+    let(:cluster) { create(:cluster, platform_kubernetes: platform) }
+    let(:project) { create(:project, path: "Path-With-Capitals") }
+    let(:environment) { create(:environment, project: project) }
+
+    subject { generator.from_environment_slug(environment.slug) }
+
+    context 'namespace per environment is enabled' do
+      context 'platform namespace is specified' do
+        let(:platform_namespace) { 'platform-namespace' }
+
+        it { is_expected.to eq "#{platform_namespace}-#{environment.slug}" }
+
+        context 'cluster is unmanaged' do
+          let(:cluster) { create(:cluster, :not_managed, platform_kubernetes: platform) }
+
+          it { is_expected.to eq platform_namespace }
+        end
+      end
+
+      context 'platform namespace is blank' do
+        let(:platform_namespace) { nil }
+        let(:mock_namespace) { 'mock-namespace' }
+
+        it 'constructs a namespace from the project and environment' do
+          expect(Gitlab::NamespaceSanitizer).to receive(:sanitize)
+            .with("#{project.path}-#{project.id}-#{environment.slug}".downcase)
+            .and_return(mock_namespace)
+
+          expect(subject).to eq mock_namespace
+        end
+      end
+    end
+
+    context 'namespace per environment is disabled' do
+      let(:cluster) { create(:cluster, :namespace_per_environment_disabled, platform_kubernetes: platform) }
+
+      context 'platform namespace is specified' do
+        let(:platform_namespace) { 'platform-namespace' }
+
+        it { is_expected.to eq platform_namespace }
+      end
+
+      context 'platform namespace is blank' do
+        let(:platform_namespace) { nil }
+        let(:mock_namespace) { 'mock-namespace' }
+
+        it 'constructs a namespace from the project and environment' do
+          expect(Gitlab::NamespaceSanitizer).to receive(:sanitize)
+            .with("#{project.path}-#{project.id}".downcase)
+            .and_return(mock_namespace)
+
+          expect(subject).to eq mock_namespace
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/prometheus/query_variables_spec.rb b/spec/lib/gitlab/prometheus/query_variables_spec.rb
index 6dc99ef26ec..3f9b245a3fb 100644
--- a/spec/lib/gitlab/prometheus/query_variables_spec.rb
+++ b/spec/lib/gitlab/prometheus/query_variables_spec.rb
@@ -23,7 +23,7 @@ describe Gitlab::Prometheus::QueryVariables do
 
     context 'with deployment platform' do
       context 'with project cluster' do
-        let(:kube_namespace) { environment.deployment_platform.cluster.kubernetes_namespace_for(project) }
+        let(:kube_namespace) { environment.deployment_namespace }
 
         before do
           create(:cluster, :project, :provided_by_user, projects: [project])
@@ -38,8 +38,8 @@ describe Gitlab::Prometheus::QueryVariables do
         let(:project2) { create(:project) }
         let(:kube_namespace) { k8s_ns.namespace }
 
-        let!(:k8s_ns) { create(:cluster_kubernetes_namespace, cluster: cluster, project: project) }
-        let!(:k8s_ns2) { create(:cluster_kubernetes_namespace, cluster: cluster, project: project2) }
+        let!(:k8s_ns) { create(:cluster_kubernetes_namespace, cluster: cluster, project: project, environment: environment) }
+        let!(:k8s_ns2) { create(:cluster_kubernetes_namespace, cluster: cluster, project: project2, environment: environment) }
 
         before do
           group.projects << project