GitHub Actions Feature Request: Run job only on `push` to configured branch

docker-after.yml

# https://help.github.com/en/categories/automating-your-workflow-with-github-actions

on:
  push:
    branch: master

name: Docker

jobs:
  docker:
    name: "Docker"

    runs-on: ubuntu-latest

    strategy:
      matrix:
        image:
          - php-7.2
          - php-7.3
          - php-7.3-with-xdebug

    steps:
      - name: Checkout
        uses: actions/checkout@master

      - name: Docker Login
        uses: actions/docker/login@master
        env:
          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
          DOCKER_PASSWORD : ${{ secrets.DOCKER_PASSWORD }}

      - name: "Build and tag Docker image"
        uses: actions/docker/cli@master
        with:
          args: build --tag localheinz/php-library-template-${{ matrix.image }} .docker/${{ matrix.image }}

      - name: "Push  Docker image"
        uses: actions/docker/cli@master
        with:
          args: push localheinz/php-library-template-${{ matrix.image }}

      - name: Docker Logout
        uses: actions/docker/cli@master
        env:
          args: logout

docker-before.yml

# https://help.github.com/en/categories/automating-your-workflow-with-github-actions

on:
  - push

name: Docker

jobs:
  docker:
    name: "Docker"

    runs-on: ubuntu-latest

    strategy:
      matrix:
        image:
          - php-7.2
          - php-7.3
          - php-7.3-with-xdebug

    steps:
      - name: Checkout
        if: github.ref == 'refs/heads/master'
        uses: actions/checkout@master

      - name: Docker Login
        if: github.ref == 'refs/heads/master'
        uses: actions/docker/login@master
        env:
          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
          DOCKER_PASSWORD : ${{ secrets.DOCKER_PASSWORD }}

      - name: "Build and tag Docker image"
        if: github.ref == 'refs/heads/master'
        uses: actions/docker/cli@master
        with:
          args: build --tag localheinz/php-library-template-${{ matrix.image }} .docker/${{ matrix.image }}

      - name: "Push  Docker image"
        if: github.ref == 'refs/heads/master'
        uses: actions/docker/cli@master
        with:
          args: push localheinz/php-library-template-${{ matrix.image }}

      - name: Docker Logout
        if: github.ref == 'refs/heads/master'
        uses: actions/docker/cli@master
        env:
          args: logout

It would be very nice if it were possible to further configure specifics of a push event that trigger a job.

Here's a diff:

--- docker-before.yml	2019-09-08 09:23:48.000000000 +0200
+++ docker-after.yml	2019-09-08 09:24:00.000000000 +0200
@@ -1,7 +1,8 @@
 # https://help.github.com/en/categories/automating-your-workflow-with-github-actions

 on:
-  - push
+  push:
+    branch: master

 name: Docker

@@ -20,30 +21,25 @@

     steps:
       - name: Checkout
-        if: github.ref == 'refs/heads/master'
         uses: actions/checkout@master

       - name: Docker Login
-        if: github.ref == 'refs/heads/master'
         uses: actions/docker/login@master
         env:
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
           DOCKER_PASSWORD : ${{ secrets.DOCKER_PASSWORD }}

       - name: "Build and tag Docker image"
-        if: github.ref == 'refs/heads/master'
         uses: actions/docker/cli@master
         with:
           args: build --tag localheinz/php-library-template-${{ matrix.image }} .docker/${{ matrix.image }}

       - name: "Push  Docker image"
-        if: github.ref == 'refs/heads/master'
         uses: actions/docker/cli@master
         with:
           args: push localheinz/php-library-template-${{ matrix.image }}

       - name: Docker Logout
-        if: github.ref == 'refs/heads/master'
         uses: actions/docker/cli@master
         env:
           args: logout

Currently, the job described in docker-before.yml will run on every push event, and even though we use if conditions to skip steps in the job

• the job is triggered
• required actions (here: actions/checkout and actions/docker/cli) are build

We could do better and save resources if the job were only triggered when we push to master (or any other specified branch).

What do you think, @nat?