Create a container image

.github/workflows/publish-image.yaml

@@ -0,0 +1,48 @@
+name: Build and publish the production container image to the GitHub Registry
+
+# Run this workflow every time on every push to the branch `release`.
+on:
+  push:
+    branches: ['feature/runnable-container']
+
+env:
+  IMAGE_NAME: imap-backup
+  REGISTRY_USER: ${{ github.actor }}
+  REGISTRY_PASSWORD: ${{ github.token }}
+  REGISTRY: ghcr.io/${{ github.repository_owner }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Build Image
+        # https://github.com/marketplace/actions/buildah-build
+        id: build-image
+        uses: redhat-actions/buildah-build@v2
+        with:
+          image: ${{ env.IMAGE_NAME }}
+          tags: latest ${{ github.sha }}
+          extra-args: |
+            --ignorefile ./container/.containerignore
+          containerfiles: |
+            ./container/Containerfile
+          labels: |
+            ${{ env.IMAGE_NAME }}:latest
+
+      - name: Publish Image
+        # https://github.com/marketplace/actions/push-to-registry
+        id: push-to-registry
+        uses: redhat-actions/push-to-registry@v2
+        with:
+          image: ${{ steps.build-image.outputs.image }}
+          tags: ${{ steps.build-image.outputs.tags }}
+          registry: ${{ secrets.REGISTRY }}
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}

container/.containerignore

@@ -0,0 +1,6 @@
+*
+!bin/imap-backup
+!Gemfile
+!imap-backup.gemspec
+!lib
+!LICENSE

container/Containerfile

@@ -0,0 +1,12 @@
+FROM docker.io/library/ruby:3.2.2-alpine3.18
+
+WORKDIR /app
+
+RUN gem install bundler --version "2.4.21"
+COPY . .
+RUN \
+  BUNDLE_WITHOUT=development bundle install --no-binstubs && \
+  rm -f /usr/local/bundle/bin/imap-backup
+ENV PATH=${PATH}:/app/bin
+
+CMD ["imap-backup", "backup", "-c", "/config/imap-backup.json"]