release: build docs as container image

Signed-off-by: David Karlsson <[email protected]>

.github/workflows/build.yml

@@ -4,6 +4,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+env:
+  IMAGE_NAME: "docs/docker-docs"
+
 on:
   push:
     # needs push event on default branch otherwise cache is evicted when pull request is merged
@@ -98,3 +101,40 @@ jobs:
           set: |
             *.cache-from=type=gha,scope=releaser
             *.cache-to=type=gha,scope=releaser,mode=max
+
+  image:
+    runs-on: ubuntu-24.04
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      -
+        name: Docker meta
+        id: meta
+        uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81 # v5.5.1
+        with:
+          images: ${{ env.IMAGE_NAME }}
+      -
+        name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKER_USER }}
+          password: ${{ secrets.DOCKER_TOKEN }}
+      -
+        name: Build website image
+        uses: docker/bake-action@v5
+        with:
+          files: |
+            docker-bake.hcl
+            ${{ steps.meta.outputs.bake-file-tags }}
+            ${{ steps.meta.outputs.bake-file-annotations }}
+          targets: image
+          set: |
+            *.cache-from=type=gha,scope=deploy-${{ env.BRANCH_NAME }}
+            *.cache-to=type=gha,scope=deploy-${{ env.BRANCH_NAME }},mode=max
+          push: ${{ github.event_name != 'pull_request' }}

Dockerfile

@@ -9,6 +9,8 @@ ARG GO_VERSION=1.23
 ARG HTMLTEST_VERSION=0.17.0
 # HUGO_VERSION sets the version of Hugo to build the site with
 ARG HUGO_VERSION=0.136.2
+# NGINX_VERSION sets the version of Nginx to use in the runtime image
+ARG NGINX_VERSION=1.27
 
 # build-base is the base stage used for building the site
 FROM ghcr.io/gohugoio/hugo:v${HUGO_VERSION} AS build-base
@@ -131,3 +133,7 @@ EOT
 FROM scratch AS release
 COPY --from=build /out /
 COPY --from=pagefind /pagefind /pagefind
+
+# image creates a Docker image for the documentation site
+FROM nginx:${NGINX_VERSION}-alpine AS image
+COPY --from=release / /usr/share/nginx/html

docker-bake.hcl

@@ -31,6 +31,19 @@ target "release" {
   provenance = false
 }
 
+target "image" {
+  args = {
+    HUGO_ENV = HUGO_ENV
+    DOCS_URL = "/"
+  }
+  target = "image"
+  attest = [
+    "type=provenance,mode=max",
+    "type=sbom",
+  ]
+  output = ["type=docker"]
+}
+
 group "validate" {
   targets = ["lint", "test", "unused-media", "test-go-redirects", "dockerfile-lint", "path-warnings"]
 }