Create env vars to override the full worker image ref

app/models/miq_ui_worker.rb

@@ -41,4 +41,8 @@ def container_port
   def container_image_name
     "manageiq-ui-worker"
   end
+
+  def container_image
+    ENV["UI_WORKER_IMAGE"] || default_image
+  end
 end

app/models/miq_worker/container_common.rb

@@ -18,7 +18,7 @@ def configure_worker_deployment(definition, replicas = 0)
         container[:imagePullPolicy] = "IfNotPresent"
       end
 
-      container[:image] = "#{container_image_namespace}/#{container_image_name}:#{container_image_tag}"
+      container[:image] = container_image
       container[:env] << {:name => "WORKER_CLASS_NAME", :value => self.class.name}
       container[:env] << {:name => "BUNDLER_GROUPS", :value => self.class.bundler_groups.join(",")}
     end
@@ -32,6 +32,14 @@ def zone_selector
       {"#{Vmdb::Appliance.PRODUCT_NAME.downcase}/zone-#{MiqServer.my_zone}" => "true"}
     end
 
+    def container_image
+      ENV["BASE_WORKER_IMAGE"] || default_image
+    end
+
+    def default_image
+      "#{container_image_namespace}/#{container_image_name}:#{container_image_tag}"
+    end
+
     def container_image_namespace
       ENV["CONTAINER_IMAGE_NAMESPACE"]
     end

app/models/miq_worker/service_worker.rb

@@ -52,5 +52,9 @@ def container_port
     def container_image_name
       "manageiq-webserver-worker"
     end
+
+    def container_image
+      ENV["WEBSERVER_WORKER_IMAGE"] || default_image
+    end
   end
 end

spec/models/miq_worker/container_common_spec.rb

@@ -92,4 +92,45 @@ def deployment_name_for(name)
       worker.scale_deployment
     end
   end
+
+  describe "#container_image" do
+    let(:generic_worker) { MiqGenericWorker.new }
+    let(:ui_worker)      { MiqUiWorker.new }
+    let(:api_worker)     { MiqWebServiceWorker.new }
+
+    it "uses the BASE_WORKER_IMAGE value for a generic worker" do
+      image_ref = "registry.example.com/manageiq/manageiq-test@sha256:2997e41a1195df90d8daf9714b619c9ae0c053f3d79e39bd8ed2d18b3c8da52a"
+      stub_const("ENV", ENV.to_h.merge("BASE_WORKER_IMAGE" => image_ref))
+      expect(generic_worker.container_image).to eq(image_ref)
+    end
+
+    it "uses the UI_WORKER_IMAGE value for a UI worker" do
+      image_ref = "registry.example.com/manageiq/manageiq-ui-test@sha256:2997e41a1195df90d8daf9714b619c9ae0c053f3d79e39bd8ed2d18b3c8da52a"
+      stub_const("ENV", ENV.to_h.merge("UI_WORKER_IMAGE" => image_ref))
+      expect(ui_worker.container_image).to eq(image_ref)
+    end
+
+    it "uses the WEBSERVER_WORKER_IMAGE value for an API worker" do
+      image_ref = "registry.example.com/manageiq/manageiq-web-test@sha256:2997e41a1195df90d8daf9714b619c9ae0c053f3d79e39bd8ed2d18b3c8da52a"
+      stub_const("ENV", ENV.to_h.merge("WEBSERVER_WORKER_IMAGE" => image_ref))
+      expect(api_worker.container_image).to eq(image_ref)
+    end
+
+    context "when CONTAINER_IMAGE_NAMESPACE is set" do
+      before { stub_const("ENV", ENV.to_h.merge("CONTAINER_IMAGE_NAMESPACE" => "registry.example.com/manageiq")) }
+
+      it "uses the correct default value" do
+        expect(generic_worker.container_image).to eq("registry.example.com/manageiq/manageiq-base-worker:latest")
+        expect(ui_worker.container_image).to eq("registry.example.com/manageiq/manageiq-ui-worker:latest")
+        expect(api_worker.container_image).to eq("registry.example.com/manageiq/manageiq-webserver-worker:latest")
+      end
+
+      it "allows tag overrides" do
+        stub_const("ENV", ENV.to_h.merge("CONTAINER_IMAGE_TAG" => "jansa-1"))
+        expect(generic_worker.container_image).to eq("registry.example.com/manageiq/manageiq-base-worker:jansa-1")
+        expect(ui_worker.container_image).to eq("registry.example.com/manageiq/manageiq-ui-worker:jansa-1")
+        expect(api_worker.container_image).to eq("registry.example.com/manageiq/manageiq-webserver-worker:jansa-1")
+      end
+    end
+  end
 end