Add docker deployment action.

.github/workflows/docker_deployment.yml

@@ -0,0 +1,54 @@
+name: Build and deploy Docker image
+
+on:
+  push:
+    branches:
+      - 'main'
+  release:
+    types: [published]
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+          fetch-depth: 0
+
+      -
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Login to DockerHub
+        uses: docker/login-action@v1 
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_ACCESS_TOKEN }}
+      -
+        name: Build and push stable release
+        if: ${{ github.event_name == 'release' && startsWith(github.event.ref, 'refs/tags') }}
+        id: docker_build_release
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: molpopgen/fwdpy11:stable
+          file: deployment/docker/Dockerfile
+          context: .
+      -
+        name: Build and push from main
+        if: github.ref == 'refs/heads/main'
+        id: docker_build_main
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: molpopgen/fwdpy11:latest
+          file: deployment/docker/Dockerfile
+          context: .
+      -
+        name: Image digest
+        run: echo ${{ steps.docker_build.outputs.digest }}

deployment/docker/Dockerfile

@@ -15,6 +15,7 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get -qq -y install cmak
   libgsl-dev \
   python3 \
   python3-pip \
-  && rm -rf /var/lib/apt/lists/*
+  && rm -rf /var/lib/apt/lists/* \
+  && rm -rf build
 
 RUN python3 -m pip install --no-cache-dir .