Merge pull request #6 from jzelinskie/release-workflow

.github: add release workflow

.github/workflows/release.yaml

@@ -0,0 +1,28 @@
+name: "Release"
+on:
+  push:
+    tags:
+    - '*'
+jobs:
+  docker:
+    name: "Publish Container Image"
+    runs-on: "ubuntu-latest"
+    steps:
+    - uses: "actions/checkout@v2"
+    - uses: "docker/setup-qemu-action@v1"
+    - uses: "docker/setup-buildx-action@v1"
+      with:
+        driver-opts: "image=moby/buildkit:master"
+    - uses: "docker/login-action@v1"
+      with:
+        registry: "quay.io"
+        username: ${{ secrets.QUAYIO_USER }}
+        password: ${{ secrets.QUAYIO_PASSWORD }}
+    - uses: "battila7/get-version-action@v2"
+      id: "get_version"
+    - uses: "docker/build-push-action@v2"
+      with:
+        push: true
+        tags: |
+          quay.io/authzed/prom-authzed-proxy:latest
+          quay.io/authzed/prom-authzed-proxy:${{ steps.get_version.outputs.version }}

README.md

@@ -1,6 +1,6 @@
 # prom-authzed-proxy
 
-[![Container Repository on Quay.io](https://quay.io/repository/authzed/prom-authzed-proxy/status "Docker Repository on Quay.io")](https://quay.io/repository/authzed/prom-authzed-proxy)
+[![Container Image](https://img.shields.io/github/v/release/authzed/prom-authzed-proxy?color=%232496ED&label=container&logo=docker "Container Image")](https://quay.io/repository/authzed/prom-authzed-proxy)
 [![License](https://img.shields.io/badge/license-Apache--2.0-blue.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
 [![Build Status](https://github.com/authzed/prom-authzed-proxy/workflows/Build%20&%20Test/badge.svg)](https://github.com/authzed/prom-authzed-proxy/actions)
 [![Mailing List](https://img.shields.io/badge/email-google%20groups-4285F4)](https://groups.google.com/g/authzed-oss)