Ensure default k8s namespace is <= 63 chars

lib/gitlab/kubernetes/default_namespace.rb

@@ -36,14 +36,17 @@ module Gitlab
         end
       end
 
-      def default_project_namespace(slug)
-        namespace_slug = "#{project.path}-#{project.id}".downcase
-
-        if cluster.namespace_per_environment?
-          namespace_slug += "-#{slug}"
-        end
+      def default_project_namespace(environment_slug)
+        maybe_environment_suffix = cluster.namespace_per_environment? ? "-#{environment_slug}" : ''
+        suffix = "-#{project.id}#{maybe_environment_suffix}"
+        namespace = project_path_slug(63 - suffix.length) + suffix
+        Gitlab::NamespaceSanitizer.sanitize(namespace)
+      end
 
-        Gitlab::NamespaceSanitizer.sanitize(namespace_slug)
+      def project_path_slug(max_length)
+        Gitlab::NamespaceSanitizer
+          .sanitize(project.path.downcase)
+          .first(max_length)
       end
 
       ##

spec/lib/gitlab/kubernetes/default_namespace_spec.rb

@@ -32,6 +32,14 @@ RSpec.describe Gitlab::Kubernetes::DefaultNamespace do
 
     subject { generator.from_environment_slug(environment.slug) }
 
+    shared_examples_for 'handles very long project paths' do
+      before do
+        allow(project).to receive(:path).and_return 'x' * 100
+      end
+
+      it { is_expected.to satisfy { |s| s.length <= 63 } }
+    end
+
     context 'namespace per environment is enabled' do
       context 'platform namespace is specified' do
         let(:platform_namespace) { 'platform-namespace' }
@@ -47,15 +55,12 @@ RSpec.describe Gitlab::Kubernetes::DefaultNamespace do
 
       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
+        it 'constructs a namespace from the project and environment slug' do
+          expect(subject).to eq "path-with-capitals-#{project.id}-#{environment.slug}"
         end
+
+        it_behaves_like 'handles very long project paths'
       end
     end
 
@@ -70,15 +75,12 @@ RSpec.describe Gitlab::Kubernetes::DefaultNamespace do
 
       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
+        it 'constructs a namespace from just the project' do
+          expect(subject).to eq "path-with-capitals-#{project.id}"
         end
+
+        it_behaves_like 'handles very long project paths'
       end
     end
   end