Enable build runner workflow

.github/workflows/build-runner.yml

@@ -0,0 +1,22 @@
+on:
+  push:
+    branches:
+    - master
+    paths:
+    - 'runner/**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: Build runner
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Build container image
+      run: make docker-build
+      working-directory: runner
+    - name: Docker Login
+      run: docker login -u summerwind -p ${{ secrets.DOCKER_ACCESS_TOKEN }}
+    - name: Push container image
+      run: make docker-push
+      working-directory: runner

runner/Dockerfile

@@ -1,8 +1,11 @@
 FROM ubuntu:18.04
 
+ARG RUNNER_VERSION
+ARG DOCKER_VERSION
+
 RUN apt update \
   && apt install curl ca-certificates -y --no-install-recommends \
-  && curl -L -o docker.tgz https://download.docker.com/linux/static/stable/x86_64/docker-19.03.5.tgz \
+  && curl -L -o docker.tgz https://download.docker.com/linux/static/stable/x86_64/docker-${DOCKER_VERSION}.tgz \
   && tar zxvf docker.tgz \
   && install -o root -g root -m 755 docker/docker /usr/local/bin/docker \
   && rm -rf docker docker.tgz \
@@ -10,9 +13,9 @@ RUN apt update \
 
 RUN mkdir -p /runner \
   && cd /runner \
-  && curl -O -L https://github.com/actions/runner/releases/download/v2.165.0/actions-runner-linux-x64-2.165.0.tar.gz \
-  && tar xzf ./actions-runner-linux-x64-2.165.0.tar.gz \
-  && rm actions-runner-linux-x64-2.165.0.tar.gz \
+  && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz \
+  && tar xzf ./runner.tar.gz \
+  && rm runner.tar.gz \
   && ./bin/installdependencies.sh
 
 COPY entrypoint.sh /runner

runner/Makefile

@@ -0,0 +1,11 @@
+NAME ?= summerwind/actions-runner
+
+RUNNER_VERSION ?= 2.165.1
+DOCKER_VERSION ?= 19.03.5
+
+docker-build:
+	docker build --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${NAME}:latest -t ${NAME}:${RUNNER_VERSION} .
+
+docker-push:
+	docker push ${NAME}:latest
+	docker push ${NAME}:${RUNNER_VERSION}