Update config map if already present on install

When an application install fails, and the user retries install, the
configmap for the application will already exists. If so, we simply
update instead of create.

changelogs/unreleased/53626-update-config-map-on-install-retry.yml

+---
+title: Update config map for gitlab managed application if already present on install
+merge_request: 22969
+author:
+type: other

lib/gitlab/kubernetes/helm/api.rb

@@ -54,7 +54,11 @@ module Gitlab
 
         def create_config_map(command)
           command.config_map_resource.tap do |config_map_resource|
-            kubeclient.create_config_map(config_map_resource)
+            if config_map_exists?(config_map_resource)
+              kubeclient.update_config_map(config_map_resource)
+            else
+              kubeclient.create_config_map(config_map_resource)
+            end
           end
         end
 
@@ -88,6 +92,12 @@ module Gitlab
           end
         end
 
+        def config_map_exists?(resource)
+          kubeclient.get_config_map(resource.metadata.name, resource.metadata.namespace)
+        rescue ::Kubeclient::ResourceNotFoundError
+          false
+        end
+
         def service_account_exists?(resource)
           kubeclient.get_service_account(resource.metadata.name, resource.metadata.namespace)
         rescue ::Kubeclient::ResourceNotFoundError

spec/lib/gitlab/kubernetes/helm/api_spec.rb

@@ -36,6 +36,7 @@ describe Gitlab::Kubernetes::Helm::Api do
   describe '#install' do
     before do
       allow(client).to receive(:create_pod).and_return(nil)
+      allow(client).to receive(:get_config_map).and_return(nil)
       allow(client).to receive(:create_config_map).and_return(nil)
       allow(client).to receive(:create_service_account).and_return(nil)
       allow(client).to receive(:create_cluster_role_binding).and_return(nil)
@@ -57,6 +58,18 @@ describe Gitlab::Kubernetes::Helm::Api do
 
         subject.install(command)
       end
+
+      context 'config map already exists' do
+        before do
+          expect(client).to receive(:get_config_map).with("values-content-configuration-#{application_name}", gitlab_namespace).and_return(resource)
+        end
+
+        it 'updates the config map' do
+          expect(client).to receive(:update_config_map).with(resource).once
+
+          subject.install(command)
+        end
+      end
     end
 
     context 'without a service account' do
@@ -88,8 +101,8 @@ describe Gitlab::Kubernetes::Helm::Api do
 
         context 'service account and cluster role binding does not exist' do
           before do
-            expect(client).to receive('get_service_account').with('tiller', 'gitlab-managed-apps').and_raise(Kubeclient::ResourceNotFoundError.new(404, 'Not found', nil))
-            expect(client).to receive('get_cluster_role_binding').with('tiller-admin').and_raise(Kubeclient::ResourceNotFoundError.new(404, 'Not found', nil))
+            expect(client).to receive(:get_service_account).with('tiller', 'gitlab-managed-apps').and_raise(Kubeclient::ResourceNotFoundError.new(404, 'Not found', nil))
+            expect(client).to receive(:get_cluster_role_binding).with('tiller-admin').and_raise(Kubeclient::ResourceNotFoundError.new(404, 'Not found', nil))
           end
 
           it 'creates a service account, followed the cluster role binding on kubeclient' do
@@ -102,8 +115,8 @@ describe Gitlab::Kubernetes::Helm::Api do
 
         context 'service account already exists' do
           before do
-            expect(client).to receive('get_service_account').with('tiller', 'gitlab-managed-apps').and_return(service_account_resource)
-            expect(client).to receive('get_cluster_role_binding').with('tiller-admin').and_raise(Kubeclient::ResourceNotFoundError.new(404, 'Not found', nil))
+            expect(client).to receive(:get_service_account).with('tiller', 'gitlab-managed-apps').and_return(service_account_resource)
+            expect(client).to receive(:get_cluster_role_binding).with('tiller-admin').and_raise(Kubeclient::ResourceNotFoundError.new(404, 'Not found', nil))
           end
 
           it 'updates the service account, followed by creating the cluster role binding' do
@@ -116,8 +129,8 @@ describe Gitlab::Kubernetes::Helm::Api do
 
         context 'service account and cluster role binding already exists' do
           before do
-            expect(client).to receive('get_service_account').with('tiller', 'gitlab-managed-apps').and_return(service_account_resource)
-            expect(client).to receive('get_cluster_role_binding').with('tiller-admin').and_return(cluster_role_binding_resource)
+            expect(client).to receive(:get_service_account).with('tiller', 'gitlab-managed-apps').and_return(service_account_resource)
+            expect(client).to receive(:get_cluster_role_binding).with('tiller-admin').and_return(cluster_role_binding_resource)
           end
 
           it 'updates the service account, followed by creating the cluster role binding' do
@@ -130,7 +143,7 @@ describe Gitlab::Kubernetes::Helm::Api do
 
         context 'a non-404 error is thrown' do
           before do
-            expect(client).to receive('get_service_account').with('tiller', 'gitlab-managed-apps').and_raise(Kubeclient::HttpError.new(401, 'Unauthorized', nil))
+            expect(client).to receive(:get_service_account).with('tiller', 'gitlab-managed-apps').and_raise(Kubeclient::HttpError.new(401, 'Unauthorized', nil))
           end
 
           it 'raises an error' do