ci: Automatically build and publish images

.github/workflows/images.yml

@@ -0,0 +1,54 @@
+name: CI image builder
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - 'ci/ciimage/**'
+      - '.github/workflows/images.yml'
+
+  pull_request:
+    branches:
+      - master
+    paths:
+      - 'ci/ciimage/**'
+      - '.github/workflows/images.yml'
+
+  # Rebuild the images every week (Sunday)
+  schedule:
+    - cron: '0 0 * * 0'
+
+jobs:
+  build:
+    name: ${{ matrix.cfg.name }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        cfg:
+          - { name: Arch Linux,       id: arch     }
+          - { name: Fedora,           id: fedora   }
+          - { name: OpenSUSE,         id: opensuse }
+          - { name: Ubuntu Eoan,      id: eoan     }
+    steps:
+      - uses: actions/checkout@v2
+
+      # Login to dockerhub
+      - name: Docker login
+        if:   github.event_name == 'push' || github.event_name == 'schedule'
+        uses: azure/docker-login@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      # Build and test
+      - name: Building the ${{ matrix.cfg.id }} image
+        run:  ./ci/ciimage/build.py -t build ${{ matrix.cfg.id }}
+      - name: Testing the ${{ matrix.cfg.id }} image
+        run:  ./ci/ciimage/build.py -t test  ${{ matrix.cfg.id }}
+
+      # Publish
+      - name: Push the ${{ matrix.cfg.id }} image
+        if:   github.event_name == 'push' || github.event_name == 'schedule'
+        run:  docker push mesonbuild/${{ matrix.cfg.id }}