[FEATURE] `no_push: true` should not complain about missing credentials

[casperdcl]

When no_push: true, don't complain about blank username/password.

Use case:

- uses: elgohr/Publish-Docker-Github-Action@master
  with:
    name: ${{ github.repository }}
    password: ${{ secrets.DOCKER_PWD }}  # obviously blank on pull_request
    username: ${{ secrets.DOCKER_USR }}  # obviously blank on pull_request
    no_push: ${{ github.event_name == 'pull_request' }}

this will allow testing that the image builds on pull requests, but won't try to login. (Neater than duplicating two different versions of the block with if: github.event_name == 'pull_request' and github.event_name != 'pull_request'.)

[elgohr]

Hey, totally understand why you come to that point. Sadly the login is necessary, due to the fact that you could depend on an image from a private registry. Makes sense?

[casperdcl]

yes but that means the login should be optional. As you say, it's only necessary for builds which require login to private registries.

Your argument is like saying github should not allow pulling public repos without login.

[casperdcl]

will change the PR slightly to allow blank login iff no_push is defined.

[casperdcl]

already updated #111 3 days ago btw...

credentials	required	not required
provided	ok	ok
not provided	fails	should not fail; fixed by #111

[elgohr]

Please give me some time, will have a look