[WIP] Make builds repeatable by tagging an image based on hash of package install

This tags a base Alpine image with the packages we use by finding
the has of the package install manifest and using that to tag
the image on hub.

Hub org needs changing, and not sure how this will work out yet.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

alpine/Dockerfile

@@ -1,34 +1,11 @@
-FROM alpine:3.4
+FROM justincormack/moby-alpine-base:0d79ff85d10a7d86067a3893e8a1f52ff3a073da
 
 ENV ARCH=x86_64
 
 RUN \
   addgroup -g 50 docker && \
   adduser -G docker -u 1001 -s /bin/sh -D -g "Docker" docker && \
-  passwd -d root && \
-  apk update && apk upgrade && \
-  apk add \
-  e2fsprogs \
-  chrony \
-  git \
-  xz \
-  iptables \
-  sfdisk \
-  lvm2 \
-  syslinux \
-  openrc \
-  busybox-initscripts \
-  alpine-conf \
-  bind-tools \
-  openssh-client \
-  strace \
-  fuse \
-  util-linux \
-  cifs-utils \
-  e2fsprogs-extra \
-  openssl \
-  jq \
-  && rm -rf /var/cache/apk/*
+  passwd -d root
 
 COPY etc /etc/
 RUN mkdir -p /etc/docker

alpine/base/.gitignore

@@ -0,0 +1 @@
+hash

alpine/base/Dockerfile

@@ -0,0 +1,26 @@
+FROM alpine:3.4
+
+RUN \
+  apk update && apk upgrade && \
+  apk add \
+  e2fsprogs \
+  chrony \
+  git \
+  xz \
+  iptables \
+  sfdisk \
+  lvm2 \
+  syslinux \
+  openrc \
+  busybox-initscripts \
+  alpine-conf \
+  bind-tools \
+  openssh-client \
+  strace \
+  fuse \
+  util-linux \
+  cifs-utils \
+  e2fsprogs-extra \
+  openssl \
+  jq \
+  && rm -rf /var/cache/apk/*

alpine/base/Makefile

@@ -0,0 +1,26 @@
+.PHONY: tag push
+
+default: push
+
+hash:
+	docker pull alpine:3.4
+	tar cf - Dockerfile | docker build --no-cache -t justincormack/moby-alpine-base:build -
+	rm -f hash
+	docker run justincormack/moby-alpine-base:build sha1sum /lib/apk/db/installed | sed 's/ .*//' > hash
+
+push: hash
+	docker pull justincormack/moby-alpine-base:$(shell cat hash) || \
+		(docker tag justincormack/moby-alpine-base:build justincormack/moby-alpine-base:latest && \
+		 docker tag justincormack/moby-alpine-base:build justincormack/moby-alpine-base:$(shell cat hash) && \
+		 docker push justincormack/moby-alpine-base:$(shell cat hash) && \
+		 docker push justincormack/moby-alpine-base:latest)
+	rm -f hash
+
+tag: hash
+	docker pull justincormack/moby-alpine-base:$(shell cat hash) || \
+		(docker tag justincormack/moby-alpine-base:build justincormack/moby-alpine-base:latest && \
+		 docker tag justincormack/moby-alpine-base:build justincormack/moby-alpine-base:$(shell cat hash))
+	rm -f hash
+
+clean:
+	rm -f hash