chore: automate builds

.github/workflows/ci.yml

@@ -0,0 +1,65 @@
+name: Build/Publish Image
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - 'Makefile'
+      - 'Dockerfile'
+      - 'VERSION'
+  pull_request:
+    paths:
+      - 'Makefile'
+      - 'Dockerfile'
+      - 'VERSION'
+
+env:
+  BUILDX_CACHE_DIR: /tmp/buildx
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Get Version Info
+      id: versions
+      run: |
+        elixir_version="$(cat VERSION | grep elixir | cut -d ' ' -f2)"
+        echo "::set-output name=elixir_version::${elixir_version}"
+
+    - name: Setup QEMU
+      uses: docker/setup-qemu-action@v1
+
+    - name: Setup Docker Buildx
+      uses: docker/setup-buildx-action@v1
+
+    - name: Cache Docker Layers
+      uses: actions/cache@v2
+      id: cache
+      with:
+        path: /tmp/buildx
+        key: buildx-elixir${{ steps.versions.outputs.elixir_version }}
+        restore-keys: |
+          buildx-elixir${{ steps.versions.outputs.elixir_version }}
+          buildx-elixir
+
+    - name: Build Image
+      env:
+        VERSION: ${{ steps.versions.outputs.elixir_version }}
+      run: make build
+
+    - name: Login
+      if: ${{ github.event_name == 'push' }}
+      uses: docker/login-action@v1
+      with:
+        username: ${{ secrets.DOCKERHUB_USERNAME }}
+        password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+    - name: Publish Image
+      if: ${{ github.event_name == 'push' }}
+      env:
+        VERSION: ${{ steps.versions.outputs.elixir_version }}
+      run: make release

Dockerfile

@@ -1,12 +1,13 @@
-FROM bitwalker/alpine-elixir:1.11.4
+ARG ELIXIR_VERSION
+FROM bitwalker/alpine-elixir:${ELIXIR_VERSION}
 
 MAINTAINER Paul Schoenfelder <paulschoenfelder@gmail.com>
 
 # Important!  Update this no-op ENV variable when this Dockerfile
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT=2021-03-15
+ENV REFRESHED_AT=2021-06-01
 
 # Install NPM
 RUN \
@@ -33,4 +34,4 @@ ONBUILD RUN mix do local.hex --force, local.rebar --force
 
 WORKDIR /opt/app
 
-CMD ["/bin/sh"]
+CMD ["bash"]

Makefile

@@ -1,9 +1,11 @@
 .PHONY: help
 
-VERSION ?= `cat VERSION`
+VERSION ?= `cat VERSION | grep elixir | cut -d' ' -f2`
 MAJ_VERSION := $(shell echo $(VERSION) | sed 's/\([0-9][0-9]*\)\.\([0-9][0-9]*\)\(\.[0-9][0-9]*\)*/\1/')
 MIN_VERSION := $(shell echo $(VERSION) | sed 's/\([0-9][0-9]*\)\.\([0-9][0-9]*\)\(\.[0-9][0-9]*\)*/\1.\2/')
 IMAGE_NAME ?= bitwalker/alpine-elixir-phoenix
+XDG_CACHE_HOME ?= /tmp
+BUILDX_CACHE_DIR ?= $(XDG_CACHE_HOME)/buildx
 
 help:
 	@echo "$(IMAGE_NAME):$(VERSION)"
@@ -18,14 +20,37 @@ shell: ## Run an Elixir shell in the image
 sh: ## Boot to a shell prompt
 	docker run --rm -it $(IMAGE_NAME):$(VERSION) /bin/bash
 
-build: ## Build the Docker image
-	docker build --force-rm -t $(IMAGE_NAME):$(VERSION) -t $(IMAGE_NAME):$(MIN_VERSION) -t $(IMAGE_NAME):$(MAJ_VERSION) -t $(IMAGE_NAME):latest - < ./Dockerfile
+setup-buildx: ## Setup a Buildx builder
+	@mkdir -p "$(BUILDX_CACHE_DIR)"
+	@if ! docker buildx ls | grep buildx-builder >/dev/null; then \
+		docker buildx create --append --name buildx-builder --driver docker-container --use && \
+		docker buildx inspect --bootstrap --builder buildx-builder; \
+	fi
+
+build: setup-buildx ## Build the Docker image
+	docker buildx build --output "type=image,push=false" \
+		--build-arg ELIXIR_VERSION=$(VERSION) \
+		--platform linux/amd64,linux/arm64 \
+		--cache-from "type=local,src=$(BUILDX_CACHE_DIR)" \
+		--cache-to "type=local,dest=$(BUILDX_CACHE_DIR)" \
+		-t $(IMAGE_NAME):$(VERSION) \
+		-t $(IMAGE_NAME):$(MIN_VERSION) \
+		-t $(IMAGE_NAME):$(MAJ_VERSION) \
+		-t $(IMAGE_NAME):latest .
+
 
 clean: ## Clean up generated images
 	@docker rmi --force $(IMAGE_NAME):$(VERSION) $(IMAGE_NAME):$(MIN_VERSION) $(IMAGE_NAME):$(MAJ_VERSION) $(IMAGE_NAME):latest
 
 rebuild: clean build ## Rebuild the Docker image
 
-release: build ## Rebuild and release the Docker image to Docker Hub
-	docker push $(IMAGE_NAME):$(VERSION)
-	docker push $(IMAGE_NAME):latest
+release: setup-buildx ## Build and release the Docker image to Docker Hub
+	docker buildx build --push \
+		--build-arg ELIXIR_VERSION=$(VERSION) \
+		--platform linux/amd64,linux/arm64 \
+		--cache-from "type=local,src=$(BUILDX_CACHE_DIR)" \
+		--cache-to "type=local,dest=$(BUILDX_CACHE_DIR)" \
+		-t $(IMAGE_NAME):$(VERSION) \
+		-t $(IMAGE_NAME):$(MIN_VERSION) \
+		-t $(IMAGE_NAME):$(MAJ_VERSION) \
+		-t $(IMAGE_NAME):latest .

VERSION

@@ -1 +1 @@
-1.11.4
+elixir: 1.11.4