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.

1 files changed, 35 insertions, 0 deletions

diff --git a/app/services/clusters/build_kubernetes_namespace_service.rb b/app/services/clusters/build_kubernetes_namespace_service.rb
new file mode 100644
index 00000000000..2574f77bbf9
--- /dev/null
+++ b/app/services/clusters/build_kubernetes_namespace_service.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Clusters
+  class BuildKubernetesNamespaceService
+    attr_reader :cluster, :environment
+
+    def initialize(cluster, environment:)
+      @cluster = cluster
+      @environment = environment
+    end
+
+    def execute
+      cluster.kubernetes_namespaces.build(attributes)
+    end
+
+    private
+
+    def attributes
+      attributes = {
+        project: environment.project,
+        namespace: namespace,
+        service_account_name: "#{namespace}-service-account"
+      }
+
+      attributes[:cluster_project] = cluster.cluster_project if cluster.project_type?
+      attributes[:environment] = environment if cluster.namespace_per_environment?
+
+      attributes
+    end
+
+    def namespace
+      Gitlab::Kubernetes::DefaultNamespace.new(cluster, project: environment.project).from_environment_slug(environment.slug)
+    end
+  end
+end