Add multi-arch build script (#21)

.dockerignore

@@ -6,3 +6,4 @@ dumpcerts.sh
 acme.json
 acme-backup.json
 traefik-certs-dumper
+build-docker.sh

.travis.yml

@@ -4,7 +4,8 @@ go:
   - 1.11.x
   - 1.x
 
-sudo: false
+services:
+  - docker
 
 env:
   - GO111MODULE=on
@@ -23,6 +24,13 @@ install:
   - echo "TRAVIS_GO_VERSION=$TRAVIS_GO_VERSION"
   - go mod download
 
+before_deploy:
+  - >
+    if ! [ "$BEFORE_DEPLOY_RUN" ]; then
+      export BEFORE_DEPLOY_RUN=1;
+      echo "${DOCKER_PASSWORD}" | docker login -u "${DOCKER_USERNAME}" --password-stdin
+    fi
+
 deploy:
   - provider: script
     skip_cleanup: true
@@ -30,3 +38,9 @@ deploy:
     on:
       tags: true
       condition: $TRAVIS_GO_VERSION =~ ^1\.x$
+  - provider: script
+    skip_cleanup: true
+    script: make publish-images
+    on:
+      tags: true
+      condition: $TRAVIS_GO_VERSION =~ ^1\.x$

Dockerfile

@@ -1,5 +1,10 @@
 FROM golang:1-alpine as builder
 
+ARG RUNTIME_HASH
+ARG GOARCH
+ARG GOARM
+ARG GOOS
+
 RUN apk --update upgrade \
     && apk --no-cache --no-progress add git make gcc musl-dev
 
@@ -10,9 +15,9 @@ COPY go.mod go.sum ./
 RUN go mod download
 
 COPY . .
-RUN make build
+RUN GOARCH=${GOARCH} GOARM=${GOARM} GOOS=${GOOS} make build
 
-FROM alpine:3.9
+FROM alpine:3.9${RUNTIME_HASH}
 RUN apk --update upgrade \
     && apk --no-cache --no-progress add ca-certificates
 

Makefile

@@ -16,7 +16,11 @@ clean:
 
 build: clean
 	@echo Version: $(VERSION) $(BUILD_DATE)
-	go build -v -ldflags '-X "github.com/ldez/traefik-certs-dumper/cmd.version=${VERSION}" -X "github.com/ldez/traefik-certs-dumper/cmd.commit=${SHA}" -X "github.com/ldez/traefik-certs-dumper/cmd.date=${BUILD_DATE}"'
+	go build -v -ldflags '-X "github.com/ldez/traefik-certs-dumper/cmd.version=${VERSION}" -X "github.com/ldez/traefik-certs-dumper/cmd.commit=${SHA}" -X "github.com/ldez/traefik-certs-dumper/cmd.date=${BUILD_DATE}"' -o traefik-certs-dumper
 
 checks:
 	golangci-lint run
+
+publish-images:
+	VERSION=$(TAG_NAME) ./build-docker.sh
+	VERSION="latest" ./build-docker.sh

build-docker.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o pipefail
+
+# safe guard
+if [ -n "$TRAVIS_TAG" ] && [ -n "$VERSION" ]; then
+  echo "Deploying..."
+else
+  echo "Skipping deploy"
+  exit 0
+fi
+
+# base docker image name
+IMAGE_NAME="ldez/traefik-certs-dumper"
+
+# only linux for now
+OS=linux
+
+# target platforms in docker manifest notation
+declare -a PLATFORMS=( "amd64" "arm.v6" "arm.v7")
+
+# images from Dockerfile
+FROM_IMAGE=$(grep "{RUNTIME_HASH}" < Dockerfile | sed "s/FROM //" | sed 's/\$.*//')
+
+# manifest cache file
+MANIFEST_FILE=/tmp/tcd-manifest.${FROM_IMAGE}.json
+
+# get platform image hash from docker manifest
+function platformHash () {
+    local ARCHITECTURE VARIANT HASH
+    read -r ARCHITECTURE VARIANT <<< "$@"
+
+    if [ -z "$VARIANT" ]; then
+        HASH=$(jq -r ".manifests[] | select(.platform.architecture == \"$ARCHITECTURE\") | .digest" < "$MANIFEST_FILE")
+    else
+        HASH=$(jq -r ".manifests[] | select(.platform.architecture == \"$ARCHITECTURE\" and .platform.variant == \"$VARIANT\") | .digest" < "$MANIFEST_FILE")
+    fi
+
+    echo "$HASH"
+}
+
+# get manifest
+if [ ! -f "$MANIFEST_FILE" ]; then
+    docker pull "$FROM_IMAGE"
+    DOCKER_CLI_EXPERIMENTAL=enabled docker manifest inspect "$FROM_IMAGE" > "$MANIFEST_FILE"
+fi
+
+# create and push images
+for platform in "${PLATFORMS[@]}"; do
+    # split architecture.version
+    IFS='.' read -r ARCHITECTURE VARIANT <<< "$platform"
+
+    # add xargs to trim whitespace
+    RUNTIME_HASH=$(platformHash "$ARCHITECTURE" "$VARIANT")
+
+    # arm architectures flavors, strip "v" prefix
+    GOARM=${VARIANT:1}
+
+    # build for target runtime image and architecture
+    docker build --build-arg="RUNTIME_HASH=@${RUNTIME_HASH}" --build-arg="GOARCH=${ARCHITECTURE}" --build-arg="GOARM=${GOARM}" -t "$IMAGE_NAME:${VERSION}-$platform" .
+
+    # push images
+    docker push "$IMAGE_NAME:${VERSION}-$platform"
+done
+
+# create manifest
+TAG_LIST=$(printf "$IMAGE_NAME:${VERSION}-%s " "${PLATFORMS[@]}")
+# shellcheck disable=SC2086
+DOCKER_CLI_EXPERIMENTAL=enabled docker manifest create --amend "$IMAGE_NAME:${VERSION}" $TAG_LIST
+
+for platform in "${PLATFORMS[@]}"; do
+    # split architecture.version
+    IFS='.' read -r ARCHITECTURE VARIANT <<< "$platform"
+
+    # docker and go architectures don't match
+    if [ "arm" == "$ARCHITECTURE" ] && [ -n "$VARIANT" ]; then
+        VARIANT="$ARCHITECTURE$VARIANT"
+    fi
+
+    DOCKER_CLI_EXPERIMENTAL=enabled docker manifest annotate "$IMAGE_NAME:${VERSION}" "$IMAGE_NAME:${VERSION}-$platform" --os "$OS" --arch "$ARCHITECTURE" --variant "$VARIANT"
+done
+
+# push manifest
+DOCKER_CLI_EXPERIMENTAL=enabled docker manifest push "$IMAGE_NAME:${VERSION}"