Pass in project as kwarg for CreateService

This enables us to have other options in the future such as passing in
`group:`.

app/controllers/projects/clusters_controller.rb

@@ -75,8 +75,8 @@ class Projects::ClustersController < Projects::ApplicationController
 
   def create_gcp
     @gcp_cluster = ::Clusters::CreateService
-      .new(project, current_user,  create_gcp_cluster_params)
-      .execute(token_in_session)
+      .new(current_user, create_gcp_cluster_params)
+      .execute(project: project, access_token: token_in_session)
 
     if @gcp_cluster.persisted?
       redirect_to project_cluster_path(project, @gcp_cluster)
@@ -91,8 +91,8 @@ class Projects::ClustersController < Projects::ApplicationController
 
   def create_user
     @user_cluster = ::Clusters::CreateService
-      .new(project, current_user,  create_user_cluster_params)
-      .execute(token_in_session)
+      .new(current_user, create_user_cluster_params)
+      .execute(project: project, access_token: token_in_session)
 
     if @user_cluster.persisted?
       redirect_to project_cluster_path(project, @user_cluster)

app/services/clusters/create_service.rb

 # frozen_string_literal: true
 
 module Clusters
-  class CreateService < BaseService
+  class CreateService
     prepend EE::Clusters::CreateService
 
-    attr_reader :access_token
+    attr_reader :current_user, :params
 
-    def execute(access_token = nil)
-      @access_token = access_token
+    def initialize(user = nil, params = {})
+      @current_user, @params = user, params.dup
+    end
 
-      raise ArgumentError.new(_('Instance does not support multiple Kubernetes clusters')) unless can_create_cluster?
+    def execute(project:, access_token: nil)
+      raise ArgumentError.new(_('Instance does not support multiple Kubernetes clusters')) unless can_create_cluster?(project)
 
-      create_cluster.tap do |cluster|
+      cluster_params = params.merge(user: current_user, projects: [project])
+      cluster_params[:provider_gcp_attributes].try do |provider|
+        provider[:access_token] = access_token
+      end
+
+      create_cluster(cluster_params).tap do |cluster|
         ClusterProvisionWorker.perform_async(cluster.id) if cluster.persisted?
       end
     end
 
     private
 
-    def create_cluster
+    def create_cluster(cluster_params)
       Clusters::Cluster.create(cluster_params)
     end
 
-    def cluster_params
-      return @cluster_params if defined?(@cluster_params)
-
-      params[:provider_gcp_attributes].try do |provider|
-        provider[:access_token] = access_token
-      end
-
-      @cluster_params = params.merge(user: current_user, projects: [project])
-    end
-
-    def can_create_cluster?
+    # EE would override this method
+    def can_create_cluster?(project)
       project.clusters.empty?
     end
   end

spec/services/clusters/create_service_spec.rb

@@ -5,7 +5,7 @@ describe Clusters::CreateService do
   let(:project) { create(:project) }
   let(:user) { create(:user) }
 
-  subject { described_class.new(project, user, params).execute(access_token) }
+  subject { described_class.new(user, params).execute(project: project, access_token: access_token) }
 
   context 'when provider is gcp' do
     context 'when project has no clusters' do