Refactor 'images' workflow, include Ubuntu image to push

Until now, the 'images' workflow was separated into two different jobs,
one for just building the images in e.g. pull requests and the other
one for building and pushing the images e.g. after a merge to the 'main'
branch, which resulted in code repetitions. Also, both jobs used
different approaches, one (build) using a 'matrix strategy' based on
the file name of the Dockerfile, the other one (build and push) having a
seperate build and push step for each Dockerfile.

With this change, both jobs have been unified into a single "build and
optionally push" job to remove the repetitions, which now also shares
the same approach - a matrix strategy based on the file names of the
Dockerfiles.

The package naming now follows a clear schema based on the file name of
the Dockerfile. 'Dockerfile' will result in a 'helmfile' package,
'Dockerfile.ubuntu' will result in a 'helmfile-ubuntu' package and so
on. In order to keep the 'helmfile-debian-stable-slim' image package
name, the 'Dockerfile.debian' had to be renamed to
'Dockerfile.debian-stable-slim' accordingly.

Furthermore, the evaluation of the condition whether a push is intended
(or not) has been moved directly to the 'push' flag of the
'docker/build-push-action'.

Signed-off-by: Patrick Hobusch <patrick.hobusch@gmail.com>

.github/actions/setup-docker-environment/action.yaml

@@ -1,38 +0,0 @@
-name: "Setup Docker"
-
-outputs:
-  sha_short:
-    description: "The short SHA used for image builds"
-    value: ${{ steps.vars.outputs.sha_short }}
-  tag:
-    description: "The tag if run against a tag, otherwise 'canary'"
-    value: ${{ steps.vars.outputs.tag }}
-
-runs:
-  using: "composite"
-  steps:
-    - name: Get Short SHA & Tag
-      id: vars
-      run: |
-        echo ::set-output name=sha_short::${GITHUB_SHA::7}
-        TAG=${GITHUB_REF##*/}
-        if [ "main" == "${TAG}" ]; then
-          TAG=canary
-        fi
-        echo ::set-output name=tag::${TAG:-canary}
-      shell: bash
-
-    - name: Set up QEMU
-      uses: docker/setup-qemu-action@v1
-
-    - name: Set up Docker Buildx
-      uses: docker/setup-buildx-action@v1
-      with:
-        version: latest
-
-    # - name: Login to DockerHub
-    #   if: ${{ github.ref == 'main' && github.event.pull_request.merged == true }}
-    #   uses: docker/login-action@v1
-    #   with:
-    #     username: ${{ inputs.username }}
-    #     password: ${{ inputs.password }}

.github/actions/setup-image-vars/action.yaml

@@ -0,0 +1,35 @@
+name: "Setup Image Variables"
+
+inputs:
+  dockerfile:
+    required: true
+
+outputs:
+  tag:
+    description: "The tag if run against a tag, otherwise 'canary'"
+    value: ${{ steps.vars.outputs.tag }}
+  suffix:
+    description: "The suffix for the image package name (if any)"
+    value: ${{ steps.vars.outputs.suffix }}
+
+runs:
+  using: "composite"
+  steps:
+    - name: Get reference and suffix
+      id: vars
+      shell: bash
+      env:
+        DOCKERFILE: ${{ inputs.dockerfile }}
+      run: |
+        TAG=${GITHUB_REF##*/}
+        if [[ $GITHUB_REF == refs/heads/main ]]; then
+            TAG=canary
+        elif [[ $GITHUB_REF == refs/pull/*/merge ]]; then
+            TAG=pullrequest  # this 'tag' is just used for caching
+        fi
+        echo ::set-output name=tag::${TAG:-canary}
+        SUFFIX=${DOCKERFILE##Dockerfile}
+        if [[ "${SUFFIX}" == "."* ]]; then
+            SUFFIX=${SUFFIX//./-}  # convert dots into dashes
+        fi
+        echo ::set-output name=suffix::${SUFFIX}

.github/workflows/images.yaml

@@ -22,18 +22,18 @@ on:
       - "Makefile"
 
 jobs:
-  build-test:
-    if: startsWith(github.ref, 'refs/pull/')
+  build:
+    name: Build
     runs-on: ubuntu-latest
     permissions:
       contents: read
-    name: Build
+      packages: write
     strategy:
       matrix:
-       include:
-         - dockerfile: Dockerfile
-         - dockerfile: Dockerfile.debian
-         - dockerfile: Dockerfile.ubuntu
+        dockerfile:
+          - Dockerfile
+          - Dockerfile.debian-stable-slim
+          - Dockerfile.ubuntu
     steps:
       - name: Checkout
         uses: actions/checkout@v3
@@ -43,29 +43,14 @@ jobs:
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v2
-
-      - name: Build
-        uses: docker/build-push-action@v3
         with:
-          file: ${{ matrix.dockerfile }}
-          platforms: linux/amd64,linux/arm64
+          version: latest
 
-  build:
-    if: github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/')
-    runs-on: ubuntu-latest
-    permissions:
-      contents: read
-      packages: write
-    name: Build and Publish
-    env:
-      DOCKERHUB_USERNAME: ${{ secrets.DOCKER_USER }}
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v3
-
-      - name: Setup Docker Environment
+      - name: Set up Image Variables
         id: vars
-        uses: ./.github/actions/setup-docker-environment
+        uses: ./.github/actions/setup-image-vars
+        with:
+          dockerfile: ${{ matrix.dockerfile }}
 
       - name: Login to GitHub Container Registry
         uses: docker/login-action@v1
@@ -74,24 +59,13 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build and Push
-        uses: docker/build-push-action@v2
+      - name: Build / Push
+        uses: docker/build-push-action@v3
         with:
-          file: Dockerfile
+          file: ${{ matrix.dockerfile }}
           platforms: linux/amd64,linux/arm64
-          push: true
+          push: ${{ github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/') }}
           tags: |
-            ghcr.io/${{ github.repository }}:${{ steps.vars.outputs.tag }}
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
-
-      - name: Build and Push (debian stable-slim)
-        uses: docker/build-push-action@v2
-        with:
-          file: Dockerfile.debian
-          platforms: linux/amd64,linux/arm64
-          push: true
-          tags: |
-            ghcr.io/${{ github.repository }}-debian-stable-slim:${{ steps.vars.outputs.tag }}
+            ghcr.io/${{ github.repository }}${{ steps.vars.outputs.suffix }}:${{ steps.vars.outputs.tag }}
           cache-from: type=gha
           cache-to: type=gha,mode=max