Fix docker: invalid reference format (#767)

* Fix local Docker actions: invalid reference format

* Create Dockerfile

* Create Dockerfile

* Update push.yml

* Revert "Create Dockerfile"

This reverts commit 9d1dbbc2c7fdf52963e55feb4148ac2b14d639d0.

* Fix lint

* fix: re-use image that is already present in repo

ubuntu:latest would pull unnecessary blobs from registry and count toward API limit

* fix: revert change

reverting due to issue in image deletion that will have to be investigated separately

Co-authored-by: Ryan <me@hackerc.at>

pkg/runner/step_context.go

@@ -506,7 +506,8 @@ func (sc *StepContext) execAsDocker(ctx context.Context, action *model.Action, a
 	if strings.HasPrefix(action.Runs.Image, "docker://") {
 		image = strings.TrimPrefix(action.Runs.Image, "docker://")
 	} else {
-		image = fmt.Sprintf("%s:%s", regexp.MustCompile("[^a-zA-Z0-9]").ReplaceAllString(actionName, "-"), "latest")
+		// "-dockeraction" enshures that "./", "./test " won't get converted to "act-:latest", "act-test-:latest" which are invalid docker image names
+		image = fmt.Sprintf("%s-dockeraction:%s", regexp.MustCompile("[^a-zA-Z0-9]").ReplaceAllString(actionName, "-"), "latest")
 		image = fmt.Sprintf("act-%s", strings.TrimLeft(image, "-"))
 		image = strings.ToLower(image)
 		basedir := actionLocation

pkg/runner/testdata/local-action-dockerfile/push.yml

@@ -9,3 +9,4 @@ jobs:
     - uses: ./actions/docker-local
       with:
         who-to-greet: 'Mona the Octocat'
+    - uses: ./localdockerimagetest_

pkg/runner/testdata/localdockerimagetest_/Dockerfile

@@ -0,0 +1,2 @@
+FROM ubuntu:latest
+CMD echo Hello