Move from Docker Hub builds to GitHub Actions

This allows us to create do a multi-arch build, resulting in
an image which is useful even on low-end IoT devices.

.github/workflows/master.yml

@@ -0,0 +1,26 @@
+name: Docker image
+
+on:
+  push:
+    branches: master
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Get release version
+        run: echo ::set-env name=RELEASE_VERSION::$(echo ${GITHUB_REF:10})
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          version: latest
+      - name: Build master
+        env:
+          DOCKER_USERNAME: 'boky'
+          DOCKER_PASSWORD: '${{ secrets.DOCKER_ACCESS_TOKEN }}'
+          PLATFORMS: "linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/ppc64le,linux/s390x"
+        run: ./build.sh -t boky/postfix --push
+

.github/workflows/pull_request.yml

@@ -0,0 +1,22 @@
+name: Validate pull request
+
+on:
+  pull_request:
+    branches: master
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          version: latest
+      - name: Run Buildx
+        env:
+          PLATFORMS: "linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/ppc64le,linux/s390x"
+        run: ./build.sh -t boky/postfix
+

.github/workflows/tags.yml

@@ -0,0 +1,24 @@
+name: Docker tag image
+
+on:
+  push:
+    tags: ['*']
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          version: latest
+      - name: Build branch / tag
+        env:
+          DOCKER_USERNAME: 'boky'
+          DOCKER_PASSWORD: '${{ secrets.DOCKER_ACCESS_TOKEN }}'
+          PLATFORMS: "linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/ppc64le,linux/s390x"
+        run: ./build.sh -t boky/postfix:$(echo ${GITHUB_REF:10}) --push
+

README.md

@@ -1,4 +1,4 @@
-# docker-postfix
+# docker-postfix ![Docker image](https://github.com/bokysan/docker-postfix/workflows/Docker%20image/badge.svg)
 Simple postfix relay host for your Docker containers. Based on Alpine Linux.
 
 

push.sh → alpine-versions.sh

@@ -2,7 +2,7 @@
 
 if [ $# -eq 0 ]; then
   echo "No alpine build versions supplied"
-  echo "example usage: ./push.sh latest 3.10 3.9"
+  echo "example usage: $0 latest 3.10 3.9"
   exit 1
 fi
 
@@ -11,10 +11,6 @@ docker login
 
 # build, tag, and push alpine versions supplied as script arguments
 base_repo=boky/postfix
-for alpine_version in "$@"
-do
-  docker build -t "$base_repo":"$alpine_version" --build-arg=ALPINE_VERSION="$alpine_version" .
-  docker push "$base_repo":"$alpine_version"
+for alpine_version in "$@"; do
+  $(dirname $0)/build.sh -t "$base_repo" --build-arg=ALPINE_VERSION="$alpine_version"
 done
-
-

build.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+# Do a multistage build
+
+export DOCKER_BUILDKIT=1
+export DOCKER_CLI_EXPERIMENTAL=enabled
+
+if ! docker buildx inspect multiarch > /dev/null; then
+    docker buildx create --name multiarch
+fi
+docker buildx use multiarch
+
+if [[ "$*" == *--push* ]]; then
+    if [[ -n "$DOCKER_USERNAME" ]] && [[ -n "$DOCKER_PASSWORD" ]]; then
+        echo "Logging into docker registry $DOCKER_REGISTRY_URL...."
+        echo "$DOCKER_PASSWORD" | docker login --username $DOCKER_USERNAME --password-stdin $DOCKER_REGISTRY_URL
+    fi
+fi
+
+if [[ -z "$PLATFORMS" ]]; then
+    PLATFORMS="linux/amd64,linux/arm64,linux/arm/v7"
+fi
+
+docker buildx build --platform $PLATFORMS . $*
+