support for automated builds

.gitignore

@@ -1,2 +1,2 @@
-rootfs.tar.xz
-images
+/images
+/**/rootfs.tar.xz

build

@@ -1,14 +1,15 @@
 #!/usr/bin/env bash
 
+declare BUILD_MASTER="${BUILD_MASTER}"
 declare BUILD_IMAGE="${BUILD_IMAGE:-alpine-builder}"
 declare BUILD_PREFIX="${BUILD_PREFIX:-alpine-build-}"
 declare PREFIXES="${PREFIXES:-gliderlabs/alpine}"
 declare MIRROR="${MIRROR:-http://dl-4.alpinelinux.org/alpine}"
-declare VERSIONS="${VERSIONS:-versions/*}"
+declare VERSIONS="${VERSIONS:-versions/**/tags}"
 
 build() {
-	declare version_files="${*:-$VERSIONS}"
-	: "${version_files:?}"
+	declare tag_files="${*:-$VERSIONS}"
+	: "${tag_files:?}"
 
 	if [[ -z $(which docker) ]]; then
 		echo "Missing docker client which is required for building"
@@ -17,42 +18,67 @@ build() {
 
 	docker build -t "$BUILD_IMAGE" builder
 
-	for file in $version_files; do
+	for file in $tag_files; do
 		local tags="$(cat "$file")"
-		local release="$(basename "$file")"
+		local release="$(basename "$(dirname "$file")")"
 		local build="${BUILD_PREFIX}${release}"
 		local master="$(echo "$PREFIXES" | cut -d' ' -f1):master"
+		local version_dir="$(dirname "$file")"
 
 		: "${build:?}" "${tags:?}" "${release:?}"
 
+		docker rm "$build" 2>/dev/null || true
+
 		docker run --name "$build" "$BUILD_IMAGE" \
 			-s \
+			-c \
 			-r "$release" \
 			-m "$MIRROR"
-		docker cp "$build":/rootfs.tar.xz .
-		docker build -t "$master" .
-
-		for tag in $tags; do
-			for prefix in $PREFIXES; do
-				docker tag -f "$master" "${prefix}:${tag}"
-				if [[ "$CIRCLE_BUILD_NUM" ]]; then
-					mkdir -p images
-					docker save "${prefix}:${tag}" \
-						| gzip -c > "images/${prefix//\//_}_${tag}_build-${CIRCLE_BUILD_NUM}.tar.gz"
-				fi
+		docker cp "$build":/rootfs.tar.xz "./$version_dir/"
+
+		if [[ "$BUILD_MASTER" ]]; then
+			docker build -t "$master" "./$version_dir/"
+
+			for tag in $tags; do
+				for prefix in $PREFIXES; do
+					docker tag -f "$master" "${prefix}:${tag}"
+					if [[ "$CIRCLE_BUILD_NUM" ]]; then
+						mkdir -p images
+						docker save "${prefix}:${tag}" \
+							| gzip -c > "images/${prefix//\//_}_${tag}_build-${CIRCLE_BUILD_NUM}.tar.gz"
+					fi
+				done
 			done
-		done
+			docker rmi "$master" || true
+		fi
 
 		docker rm "$build" || true
-		docker rmi "$master" || true
-		rm -f rootfs.tar.xz
+	done
+}
+
+commit() {
+	declare tag_files="${*:-$VERSIONS}"
+	local build_num="${CIRCLE_BUILD_NUM:-nobuild}"
+
+	for file in $tag_files; do
+		local release="$(basename "$(dirname "$file")")"
+		local version_dir="$(dirname "$file")"
+		local current_branch=$(git rev-parse --abbrev-ref HEAD)
+
+		: "${release:?}"
+
+		git checkout -B "rootfs-$release"
+		git add -f -- "./$version_dir/rootfs.tar.xz"
+		git commit -m "pushing release $release for build $build_num"
+		git push -f origin "rootfs-$release"
+		git checkout "$current_branch"
 	done
 }
 
 test() {
-	declare version_files="${*:-$VERSIONS}"
+	declare tag_files="${*:-$VERSIONS}"
 	local repo="$(echo "$PREFIXES" | cut -d' ' -f1)"
-	for file in $version_files; do
+	for file in $tag_files; do
 		local tag="$(head -1 "$file")"
 		if docker inspect "${repo}:${tag}" >/dev/null 2>&1; then
 			docker run "${repo}:${tag}" apk add --update openssl || exit 1
@@ -65,6 +91,7 @@ main() {
 	cmd="$1"
 	case "$cmd" in
 		test)		shift; test "$@";;
+		commit)	shift; commit "$@";;
 		*)			build "$@";;
 	esac
 }

builder/Dockerfile

@@ -9,6 +9,7 @@ RUN apt-get update \
   && apt-get clean \
   && rm -rf /var/lib/{dpkg,apt,cache,log}
 
-ADD ./mkimage-alpine.sh /mkimage.sh
+COPY scripts/mkimage-alpine.sh /mkimage.sh
+COPY scripts/apk-install /apk-install
 
 ENTRYPOINT ["/mkimage.sh"]

builder/README.md

@@ -0,0 +1,13 @@
+# Alpine Linux rootfs Builder
+
+This builder image constructs a Alpine Linux `rootfs.tar.xz` for us to use when building the base Alpine Linux image. The `mkimage-alpine.sh` script does all the heavy lifting. During the configuration of the image we add our `apk-install` convenience script.
+
+## Options
+
+The builder takes several options:
+
+* `-r <release>`: The release tag to use (such as `edge` or `v3.1`).
+* `-m <mirror>`: The mirror URL base. Defaults to `http://nl.alpinelinux.org/alpine`.
+* `-s`: Saves the rootfs to `/rootfs.tar.xz` so it can be later copied.
+* `-c`: Adds the `apk-install` script to the resulting rootfs.
+* `-e`: Adds extra `edge/main` and `edge/testing` pins to the repositories file.

builder/mkimage-alpine.sh → builder/scripts/mkimage-alpine.sh

@@ -14,7 +14,7 @@ set -e
 }
 
 usage() {
-	printf >&2 '%s: [-r release] [-m mirror] [-s] [-e]\n' "$0"
+	printf >&2 '%s: [-r release] [-m mirror] [-s] [-e] [-c]\n' "$0"
 	exit 1
 }
 
@@ -45,6 +45,7 @@ conf() {
 		[ $REL = "edge" ] || printf '%s\n' "@edge $MIRROR/edge/main" >> $ROOTFS/etc/apk/repositories
 		printf '%s\n' "@testing $MIRROR/edge/testing" >> $ROOTFS/etc/apk/repositories
 	}
+	[ $ADD_APK_SCRIPT -eq 1 ] && cp /apk-install $ROOTFS/usr/sbin/apk-install
 	rm -f $ROOTFS/var/cache/apk/*
 }
 
@@ -54,7 +55,7 @@ save() {
 	tar --numeric-owner -C $ROOTFS -c . | xz > rootfs.tar.xz
 }
 
-while getopts "hr:m:se" opt; do
+while getopts "hr:m:sec" opt; do
 	case $opt in
 		r)
 			REL=$OPTARG
@@ -68,6 +69,9 @@ while getopts "hr:m:se" opt; do
 		e)
 			REPO_EXTRA=1
 			;;
+		c)
+			ADD_APK_SCRIPT=1
+			;;
 		*)
 			usage
 			;;
@@ -77,6 +81,7 @@ done
 REL=${REL:-edge}
 MIRROR=${MIRROR:-http://nl.alpinelinux.org/alpine}
 SAVE=${SAVE:-0}
+ADD_APK_SCRIPT=${ADD_APK_SCRIPT:-0}
 REPO=$MIRROR/$REL/main
 REPO_EXTRA=${REPO_EXTRA:-0}
 ARCH=$(uname -m)

circle.yml

@@ -1,6 +1,9 @@
 general:
   artifacts:
     - "images"
+  branches:
+    ignore:
+      - /rootfs-.*/
 
 machine:
   services:
@@ -15,7 +18,7 @@ dependencies:
     - ./build:
         parallel: true
         files:
-          - versions/*
+          - versions/**/tags
     - mkdir -p ~/docker; docker save alpine-builder > ~/docker/builder.tar
     - docker images
 
@@ -32,3 +35,5 @@ deployment:
           parallel: true
       - docker push gliderlabs/alpine:
           parallel: true
+      - ./build commit:
+          parallel: true

docs/build.md

@@ -8,7 +8,7 @@ A convenience `build` script is included that builds the image and runs basic te
 
 The image is built using a builder Docker container based on the `debian` image. This builder image lives in the `builder` sub-directory of the project and uses a `mkimage-alpine.sh` script to generate a Alpine Linux `rootfs.tar.gz` file. This file then gets copied to the root of the project so we can build the main Alpine Linux image by just using the `ADD` command to automatically untar the components to the resulting image.
 
-The build script takes a glob of files as an argument. Each of these files describes the version of Alpine Linux to build in the file name and each line of the file are the tags that will be applied to the resulting image. By default, we use the included files in the `versions` directory.
+The build script takes a glob of `tags` files as an argument. Each of these files lives in a folder that describes the version of Alpine Linux to build in the parent directory name and each line of the file are the tags that will be applied to the resulting image. By default, we use the included glob of `versions/**/tags`.
 
 ## Test
 

versions/edge/Dockerfile

@@ -0,0 +1,2 @@
+FROM scratch
+ADD rootfs.tar.xz /

versions/v2.6/Dockerfile

@@ -0,0 +1,2 @@
+FROM scratch
+ADD rootfs.tar.xz /

versions/v2.7/Dockerfile

@@ -0,0 +1,2 @@
+FROM scratch
+ADD rootfs.tar.xz /

versions/v3.1/Dockerfile

@@ -0,0 +1,2 @@
+FROM scratch
+ADD rootfs.tar.xz /