CI: add workflow to build multi-arch images for dockerhub

.github/workflows/dockerhub.yml

@@ -0,0 +1,68 @@
+name: Dockerhub Dev
+
+on:
+  push:
+    branches-ignore:
+      - coverity_scan
+  workflow_dispatch:
+
+env:
+  CI: 1
+  GH_ACTIONS: 1
+  DEBIAN_FRONTEND: noninteractive
+  APT_OPTS: "-y --no-install-recommends"
+
+jobs:
+  #
+  #  Run docker target for each given OS and ARCH. This will
+  #  build the Docker images.
+  #
+  docker:
+    runs-on: ubuntu-22.04
+
+    strategy:
+      matrix:
+        os:
+          - ubuntu
+          - alpine
+
+        arch:
+          - amd64
+          - arm32v5
+          - arm32v6
+          - arm32v7
+          - arm64v8
+
+      fail-fast: false
+
+    name: "${{ matrix.os }}-${{ matrix.arch }}"
+
+    steps:
+
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 1
+
+    - name: Regenerate Dockerfiles
+      run: |
+        rm scripts/docker/dists/*/Dockerfile || true
+        make docker.regen
+
+    - name: Install qemu
+      run: |
+        apt-get update
+        apt-get install ${APT_OPTS} qemu-user-static
+
+    - name: Build docker image
+      run: |
+        make docker-${{ matrix.os }} DOCKER_TAG="freeradius-dev" DOCKER_BUILD_ARGS="--no-cache --platform linux/${{ matrix.arch }}"
+
+    #
+    #  If the CI has failed and the branch is ci-debug then start a tmate
+    #  session. SSH rendezvous point is emited continuously in the job output.
+    #
+    - name: "Debug: Start tmate"
+      uses: mxschmitt/action-tmate@v3
+      with:
+        limit-access-to-actor: true
+      if: ${{ github.ref == 'refs/heads/ci-debug' && failure() }}