Add GitHub workflow file to build/tag/push custom docker images

This allows docker images with a custom tag/name to be created on demand for any branch containing this workflow and pushed to the specified docker repository.  Two versions of the docker image will always be pushed, one ending with -latest and one ending with the workflow run number, e.g. my-custom-image-name-latest and my-custom-image-name-42.

This should help make it easier to customize Community Edition instances, test pull requests/development branches, and to provide docker images of long running branches (large alpha/beta features) for community testing.

Author: Exairnous

.github/workflows/custom-docker-build-push.yml

@@ -0,0 +1,129 @@
+# Based on the workflow by BrandonP from https://github.com/mikemorran/hubs/blob/master/.github/workflows/ce-build.yml
+# Input masking referenced from https://dev.to/leading-edje/masking-input-parameters-in-github-actions-1ci
+
+# Common registry base URLs:
+# Docker Hub: docker.io
+# GitHub: ghcr.io
+
+name: custom-docker-build-push
+
+on:
+  workflow_dispatch:
+    inputs:
+      Override_Registry_Base_URL:
+        type: string
+      Override_Registry_Username:
+        type: string
+      Override_Registry_Password:
+        type: string
+      Override_Registry_Namespace:
+        type: string
+      Override_Image_Tag:
+        type: string
+      Override_Dockerfile:
+        type: string
+      Override_Code_Path:
+        type: string
+      Use_Build_Cache:
+        type: boolean
+        default: true
+
+# Add in default values for the inputs plus define any missing variables we need.
+# Everything should take their values from env rather than inputs.
+env:
+  Registry_Base_URL: ${{ inputs.Override_Registry_Base_URL || vars.REGISTRY_BASE_URL }}
+# Registry_Username: This must be added in each job that needs it.
+# Registry_Password: This must be added in each job that needs it.
+  Registry_Namespace: ${{ inputs.Override_Registry_Namespace || vars.REGISTRY_NAMESPACE }}
+  Image_Tag: ${{ inputs.Override_Image_Tag || github.ref_name }}
+  Dockerfile: ${{ inputs.Override_Dockerfile || 'RetPageOriginDockerfile' }}
+  Code_Path: ${{ inputs.Override_Code_Path }}
+  Use_Build_Cache: ${{ inputs.Use_Build_Cache }}
+# repo_name: This must be added in each job that needs it.
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Assign username from secret
+        if: ${{ inputs.Override_Registry_Username == ''}}
+        run: |
+          echo "Registry_Username=${{ secrets.REGISTRY_USERNAME }}" >> "$GITHUB_ENV"
+
+      - name: Assign username from input
+        if: ${{ inputs.Override_Registry_Username != ''}}
+        run: |
+          USERNAME=$(jq -r '.inputs.Override_Registry_Username' $GITHUB_EVENT_PATH)
+          echo ::add-mask::$USERNAME
+          echo Registry_Username=$USERNAME >> $GITHUB_ENV
+
+      - name: Assign password from secret
+        if: ${{ inputs.Override_Registry_Password == ''}}
+        run: |
+          echo "Registry_Password=${{ secrets.REGISTRY_PASSWORD }}" >> "$GITHUB_ENV"
+
+      - name: Assign password from input
+        if: ${{ inputs.Override_Registry_Password != ''}}
+        run: |
+          PASSWORD=$(jq -r '.inputs.Override_Registry_Password' $GITHUB_EVENT_PATH)
+          echo ::add-mask::$PASSWORD
+          echo Registry_Password=$PASSWORD >> $GITHUB_ENV
+
+      - name: Add the repository name as an env variable
+        run: |
+          echo "repo_name=${GITHUB_REPOSITORY#*/}" >> "$GITHUB_ENV"
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          install: true
+
+      - name: Login to container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.Registry_Base_URL }}
+          username: ${{ env.Registry_Username }}
+          password: ${{ env.Registry_Password }}
+
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          path: "./repo"
+
+      - name: Use Code_Path for multirepo
+        if: ${{ env.Code_Path != ''}}
+        run: |
+          mkdir ./_repo
+          cp -rf ./repo/${{ env.Code_Path }}/* ./_repo
+          rm -rf ./repo
+          mv ./_repo ./repo
+          ls ./repo
+
+      - name: Docker Buildx setup
+        uses: docker/setup-buildx-action@v3
+        with:
+          install: true
+
+      - name: Docker Build and Push (with cache)
+        if: ${{ fromJSON(env.Use_Build_Cache) == true }}
+        uses: docker/build-push-action@v6
+        with:
+          context: repo/
+          file: repo/${{ env.Dockerfile }}
+          tags: ${{ env.Registry_Base_URL }}/${{ env.Registry_Namespace }}/${{ env.repo_name }}:${{ env.Image_Tag }}-latest,${{ env.Registry_Base_URL }}/${{ env.Registry_Namespace }}/${{ env.repo_name }}:${{ env.Image_Tag }}-${{ github.run_number }}
+          cache-from: type=registry,ref=${{ env.Registry_Base_URL }}/${{ env.Registry_Namespace }}/${{ env.repo_name }}:buildcache
+          cache-to: type=registry,ref=${{ env.Registry_Base_URL }}/${{ env.Registry_Namespace }}/${{ env.repo_name }}:buildcache,mode=max,image-manifest=true,oci-mediatypes=true
+          push: true
+
+      - name: Docker Build and Push (no cache)
+        if: ${{ fromJSON(env.Use_Build_Cache) == false }}
+        uses: docker/build-push-action@v6
+        with:
+          context: repo/
+          file: repo/${{ env.Dockerfile }}
+          tags: ${{ env.Registry_Base_URL }}/${{ env.Registry_Namespace }}/${{ env.repo_name }}:${{ env.Image_Tag }}-latest,${{ env.Registry_Base_URL }}/${{ env.Registry_Namespace }}/${{ env.repo_name }}:${{ env.Image_Tag }}-${{ github.run_number }}
+          push: true