Issue #3673: Add UpdateTest github workflow.

.github/workflows/docker_image_update_test.yml

@@ -0,0 +1,135 @@
+%YAML 1.1
+---
+name: 'DockerImageUpdateTest'
+# Adapted from https://github.com/marketplace/actions/docker-image-update-checker#minimal
+
+# TODO: check the relevant tags in rel-10_0, rel-10_1, rel-11_0 and trigger rebuilds in these commits
+# TODO: saner setup which branch uses which base image
+
+on:
+
+  # The trigger on 'workflow_dispatch' allows manual start
+  # on https://github.com/RotherOSS/otobo/actions/workflows/docker_image_update_checker.yml
+  workflow_dispatch:
+
+#  # The trigger on 'schedule' allows to run daily. Time is in UTC declared in cron syntax.
+#  # The scheduled jobs run only on the default branch.
+#  schedule:
+#    - cron: '37 6 * * *'
+
+jobs:
+  CheckDockerImageUpdate:
+    runs-on: 'ubuntu-latest'
+    strategy:
+
+      # set up a loop over OTOBO branches
+      matrix:
+        major_minor: [ '11_0_6', ]
+        include:
+          - major_minor: '11_0_6'
+            base_image: 'perl:5.38-bookworm'
+
+    steps:
+
+      - name: Setting up the environment file
+        run: |
+          major_minor="${{ matrix.major_minor }}"
+          docker_tag="test-${major_minor}"
+          mixed_case_repository="${{ github.repository }}"
+          lowercased_repository="${mixed_case_repository,,}"
+          build_date=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+          (
+            echo "otobo_branch=rel-${major_minor}"
+            echo "otobo_base_image=${{ matrix.base_image }}"
+            echo "otobo_docker_tag=${docker_tag}"
+            echo "otobo_image=${lowercased_repository}:${docker_tag}"
+            echo "otobo_build_date=${build_date}"
+          ) >> $GITHUB_ENV
+
+      -
+        # this step sets ${{ steps.check.outputs.needs-updating }}
+        name: Check whether base image was updated
+        id: check
+        uses: lucacome/docker-image-update-checker@v1
+        with:
+          base-image: ${{ env.otobo_base_image }}
+          image:      ${{ env.otobo_image }}
+
+      -
+        # print the result in any case
+        name: Report the check result
+        run: |
+          echo "The OTOBO web image needs updating: ${{ steps.check.outputs.needs-updating }}"
+
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      -
+        name: 'check out the relevant OTOBO branch'
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ env.otobo_branch }}
+
+      -
+        # needed for build arg GIT_COMMIT
+        # can't use github.sha here as we need the commit of the checked out branch
+        name: 'get the commit SHA of the current checkout'
+        run: echo "otobo_commit=$(git log -1 '--format=format:%H')" >> $GITHUB_ENV
+
+      -
+        # build the image, not pushing yet, no pushing as DockerHub access is not set up yet
+        # Caching with Github Actions Cache, limited to 10 GB
+        # context: .  indicates that the current checkout is used
+        name: Build
+        uses: docker/build-push-action@v6
+        with:
+          load: true
+          context: .
+          file: otobo.web.dockerfile
+          pull: true
+          build-args: |
+            BUILD_DATE=${{ env.otobo_build_date }}
+            DOCKER_TAG=${{ env.otobo_docker_tag }}
+            GIT_REPO=${{ github.repositoryUrl }}
+            GIT_BRANCH=${{ env.otobo_branch }}
+            GIT_COMMIT=${{ env.otobo_commit }}
+          target: otobo-web
+          tags: ${{ env.otobo_image }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max`
+
+      -
+        # otobo_first_time hasn't run yet, so /opt/otobo is still empty
+        name: Info
+        run: |
+          docker run --rm -w /opt/otobo_install/otobo_next --entrypoint /bin/bash $otobo_image -c "more git-repo.txt git-branch.txt git-commit.txt RELEASE | cat"
+
+      -
+        # login to Docker Hub only after the build
+        name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      -
+        # finally upload to DockerHub
+        # the built image is already available in the job
+        name: Push to DockerHub
+        uses: docker/build-push-action@v6
+        with:
+          push: true
+          context: .
+          file: otobo.web.dockerfile
+          pull: true
+          build-args: |
+            BUILD_DATE=${{ env.otobo_build_date }}
+            DOCKER_TAG=${{ env.otobo_docker_tag }}
+            GIT_REPO=${{ github.repositoryUrl }}
+            GIT_BRANCH=${{ env.otobo_branch }}
+            GIT_COMMIT=${{ env.otobo_commit }}
+          target: otobo-web
+          tags: ${{ env.otobo_image }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max`