Refactor monitor tests to use k3s

Prior to this change, tests were
using GKE as a Kubernetes service.
These GKE setups are expensive and
costly.

This change uses K3s as a Service,
replacing GKE due to a faster,
cost effective results.

qa/qa/page/project/operations/kubernetes/add_existing.rb

@@ -20,7 +20,7 @@ module QA
             end
 
             def set_api_url(api_url)
-              fill_in 'cluster_platform_kubernetes_attributes_api_url', with: api_url
+              fill_in 'cluster_platform_kubernetes_attributes_api_url', with: QA::Runtime::Env.cluster_api_url || api_url
             end
 
             def set_ca_certificate(ca_certificate)

qa/qa/runtime/env.rb

@@ -107,6 +107,10 @@ module QA
         ENV['CI'] || ENV['CI_SERVER']
       end
 
+      def cluster_api_url
+        ENV['CLUSTER_API_URL']
+      end
+
       def qa_cookies
         ENV['QA_COOKIES'] && ENV['QA_COOKIES'].split(';')
       end

qa/qa/service/cluster_provider/k3s.rb

@@ -10,6 +10,7 @@ module QA
 
         def setup
           @k3s = Service::DockerRun::K3s.new.tap do |k3s|
+            k3s.remove!
             k3s.register!
 
             shell "kubectl config set-cluster k3s --server https://#{k3s.host_name}:6443 --insecure-skip-tls-verify"

qa/qa/service/docker_run/k3s.rb

@@ -33,7 +33,9 @@ module QA
             --name #{@name}
             --publish 6443:6443
             --privileged
-            #{@image} server --cluster-secret some-secret
+            #{@image} server
+            --cluster-secret some-secret
+            --no-deploy traefik
           CMD
 
           command.gsub!("--network #{network} ", '') unless QA::Runtime::Env.running_in_ci?

qa/qa/specs/features/browser_ui/8_monitor/all_monitor_core_features_spec.rb

@@ -2,9 +2,9 @@
 
 module QA
   RSpec.describe 'Monitor' do
-    describe 'with Prometheus in a Gitlab-managed cluster', :orchestrated, :kubernetes do
+    describe 'with Prometheus in a Gitlab-managed cluster', :orchestrated, :kubernetes, :requires_admin do
       before :all do
-        @cluster = Service::KubernetesCluster.new.create!
+        @cluster = Service::KubernetesCluster.new(provider_class: Service::ClusterProvider::K3s).create!
         @project = Resource::Project.fabricate_via_api! do |project|
           project.name = 'monitoring-project'
           project.auto_devops_enabled = true

qa/qa/specs/features/ee/browser_ui/8_monitor/all_monitor_features_spec.rb

@@ -5,7 +5,7 @@ module QA
   RSpec.describe 'Monitor' do
     describe 'with Prometheus in a Gitlab-managed cluster', :orchestrated, :kubernetes do
       before :all do
-        @cluster = Service::KubernetesCluster.new.create!
+        @cluster = Service::KubernetesCluster.new(provider_class: Service::ClusterProvider::K3s).create!
         @project = Resource::Project.fabricate_via_api! do |project|
           project.name = 'monitoring-project'
           project.auto_devops_enabled = true