add dockerfile and workflow for container build

Author: twsearle

.github/workflows/build_ci_image.yml

@@ -0,0 +1,80 @@
+name: Create and publish the CI docker image
+
+# Configures this workflow to run when triggered.
+on:
+  push:
+    tags:
+      - v**
+  workflow_dispatch:
+
+# Defines two custom environment variables for the workflow. These are used for
+# the Container registry domain, and a name for the Docker image that this
+# workflow builds.
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: darth/orca-jedi/ci-almalinux9
+
+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
+      attestations: write
+      id-token: write
+      #
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      # Uses the `docker/login-action` action to log in to the Container
+      # registry registry using the account and password that will publish the
+      # packages. Once published, the packages are scoped to the account
+      # defined here.
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GH_PAT }}
+      # This step uses
+      # [docker/metadata-action](https://github.com/docker/metadata-action#about)
+      # to extract tags and labels that will be applied to the specified image.
+      # The `id` "meta" allows the output of this step to be referenced in a
+      # subsequent step. The `images` value provides the base name for the tags
+      # and labels.
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+      # This step uses the `docker/build-push-action` action to build the
+      # image, based on your repository's `Dockerfile`. If the build succeeds,
+      # it pushes the image to GitHub Packages.  It uses the `context`
+      # parameter to define the build's context as the set of files located in
+      # the specified path. For more information, see
+      # "[Usage](https://github.com/docker/build-push-action#usage)" in the
+      # README of the `docker/build-push-action` repository.  It uses the
+      # `tags` and `labels` parameters to tag and label the image with the
+      # output from the "meta" step.
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          file: ./ci/Dockerfile.almalinux9
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+      # This step generates an artifact attestation for the image, which is an
+      # unforgeable statement about where and how it was built. It increases
+      # supply chain security for people who consume the image. For more
+      # information, see
+      # "[AUTOTITLE](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds)."
+      - name: Generate artifact attestation
+        uses: actions/attest-build-provenance@v1
+        with:
+          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          subject-digest: ${{ steps.push.outputs.digest }}
+          push-to-registry: true