Support building xbps-src masterdirs

Author: the-maldridge

.github/workflows/masterdirs.yml

@@ -0,0 +1,44 @@
+---
+name: masterdirs
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: "Version tag"
+        required: true
+
+jobs:
+  main:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        arch:
+          - x86_64
+          - x86_64-musl
+          - i686
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@master
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login to GCHR
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: void-robot
+          password: ${{ secrets.CR_PAT }}
+      - name: Build and push
+        id: docker_build
+        uses: docker/build-push-action@v2
+        with:
+          file: Dockerfile.masterdir
+          build-args: |
+            ARCH=${{ matrix.arch }}
+            BOOTSTRAP_VERSION=c45f924
+          push: true
+          tags: |
+            ghcr.io/void-linux/xbps-src-masterdir:latest-${{ matrix.arch }}
+            ghcr.io/void-linux/xbps-src-masterdir:${{ github.event.inputs.version }}-${{ matrix.arch }}

Dockerfile.masterdir

@@ -0,0 +1,19 @@
+ARG BOOTSTRAP_SOURCE=ghcr.io/void-linux/docker-bootstrap
+ARG BOOTSTRAP_VERSION=latest
+FROM ${BOOTSTRAP_SOURCE}:${BOOTSTRAP_VERSION} as build
+COPY keys/* /target/var/db/xbps/keys/
+ARG REPOSITORY=https://alpha.de.repo.voidlinux.org
+ARG ARCH=x86_64
+RUN XBPS_ARCH=${ARCH} xbps-install -yMUS \
+        --repository=${REPOSITORY}/current \
+        --repository=${REPOSITORY}/current/musl \
+        -r /target \
+        base-chroot
+
+FROM scratch
+LABEL org.opencontainers.image.source https://github.com/void-linux/void-docker
+COPY --from=build /target /
+RUN xbps-reconfigure -a && \
+        rm -r /var/cache/xbps
+
+CMD ["/bin/sh"]