Refactor main.go and introduce make run-scaleset to be able to run manager locally (#2337)

config/manager/env-replacement.yaml

@@ -0,0 +1,10 @@
+source:
+  kind: Deployment
+  name: controller-manager
+  fieldPath: spec.template.spec.containers.[name=manager].image
+targets:
+- select:
+    kind: Deployment
+    name: controller-manager
+  fieldPaths:
+  - spec.template.spec.containers.[name=manager].env.[name=CONTROLLER_MANAGER_CONTAINER_IMAGE].value

config/manager/kustomization.yaml

@@ -6,3 +6,6 @@ images:
 - name: controller
   newName: summerwind/actions-runner-controller
   newTag: dev
+
+replacements:
+- path: env-replacement.yaml

config/manager/manager.yaml

@@ -50,10 +50,8 @@ spec:
               optional: true
         - name: GITHUB_APP_PRIVATE_KEY
           value: /etc/actions-runner-controller/github_app_private_key
-        - name: CONTROLLER_MANAGER_POD_NAME
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.name
+        - name: CONTROLLER_MANAGER_CONTAINER_IMAGE
+          value: CONTROLLER_MANAGER_CONTAINER_IMAGE
         - name: CONTROLLER_MANAGER_POD_NAMESPACE
           valueFrom:
             fieldRef: