From 9f6578783beccd39593f3bb6ecd4a8c316f1206e Mon Sep 17 00:00:00 2001
From: Rolf Neugebauer <rolf.neugebauer@docker.com>
Date: Thu, 18 May 2017 15:27:39 +0100
Subject: [PATCH] pkg: Roll the swap package from linuxkit/alpine

Also convert to a multi-stage build and make the
make the HUB org/registry build time configurable.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
---
 pkg/swap/Dockerfile | 28 ++++++++++++++++------------
 pkg/swap/Makefile   | 35 ++++++++++-------------------------
 2 files changed, 26 insertions(+), 37 deletions(-)

diff --git a/pkg/swap/Dockerfile b/pkg/swap/Dockerfile
index 9a6d9e002..955415aa1 100644
--- a/pkg/swap/Dockerfile
+++ b/pkg/swap/Dockerfile
@@ -1,13 +1,17 @@
-FROM alpine:3.5
+FROM linuxkit/alpine:6336329f15b4166514782eaa555cf0ffd35c519c@sha256:f6c2ce92910b1d6e4e5557850a554f4a3ae9f66c1e89ad86a24d6c6e550f165e AS mirror
+RUN mkdir -p /out/etc/apk && cp -r /etc/apk/* /out/etc/apk/
+RUN apk add --no-cache --initdb -p /out \
+    alpine-baselayout \
+    busybox \
+    cryptsetup \
+    musl \
+    util-linux
+RUN rm -rf /out/etc/apk /out/lib/apk /out/var/cache
 
-# swap command - only minimal Alpine install
-
-# use util-linux to get swapfile utils, cryptsetup
-#   at some point, hopefully use our own mkswap and swapon, as well as cryptsetup
-RUN apk add --update util-linux cryptsetup
-
-# add the entrypoint and make it executable
-COPY . ./
-
-# ENTRYPOINT
-ENTRYPOINT swap.sh
+FROM scratch
+ENTRYPOINT []
+CMD []
+WORKDIR /
+COPY --from=mirror /out/ /
+COPY /swap.sh .
+ENTRYPOINT ["swap.sh"]
diff --git a/pkg/swap/Makefile b/pkg/swap/Makefile
index 06e89bdcd..1e9783a81 100644
--- a/pkg/swap/Makefile
+++ b/pkg/swap/Makefile
@@ -1,30 +1,15 @@
-# copy from mount
-.PHONY: tag push clean
-
-BASE=alpine:3.5
-IMAGE=linuxkit/swap
-
+.PHONY: tag push
 default: push
 
-hash: Dockerfile swap.sh
-	DOCKER_CONTENT_TRUST=1 docker pull $(BASE)
-	tar cf - $^ | docker build --no-cache -t $(IMAGE):build -
-	docker run --rm --entrypoint /bin/sh $(IMAGE):build -c "cat $^ /lib/apk/db/installed | sha1sum" | sed 's/ .*//' > $@
+ORG?=linuxkit
+IMAGE=swap
+DEPS=Dockerfile swap.sh
 
-push: hash
-	docker pull $(IMAGE):$(shell cat hash) || \
-		(docker tag $(IMAGE):build $(IMAGE):$(shell cat hash) && \
-		 docker push $(IMAGE):$(shell cat hash))
-	docker rmi $(IMAGE):build
-	rm -f hash
+HASH?=$(shell git ls-tree HEAD -- ../$(notdir $(CURDIR)) | awk '{print $$3}')
 
-tag: hash
-	docker pull $(IMAGE):$(shell cat hash) || \
-		docker tag $(IMAGE):build $(IMAGE):$(shell cat hash)
-	docker rmi $(IMAGE):build
-	rm -f hash
+tag: $(DEPS)
+	docker build --squash --no-cache --network=none -t $(ORG)/$(IMAGE):$(HASH) .
 
-clean:
-	rm -f hash
-
-.DELETE_ON_ERROR:
+push: tag
+	docker pull $(ORG)/$(IMAGE):$(HASH) || \
+	docker push $(ORG)/$(IMAGE):$(HASH)