build-docker: Updates for multi-arch release

 o Set -e to abort script if a command fails.
 o Allow custom docker 'TAG' from the environment.
 o Move arch suffix to version to allow all images to
   be put into a single repository.
 o Enable cross builds.  When doing cross builds where the
   host and target architectures are different 'RUN mkdir'
   will fail since the target container cannot be run on
   the host.  To work around this, create the directories
   in build-docker, then use ADD in the Dockerfile.
 o Add Dockerfile-release.arm64

Signed-off-by: Geoff Levand <geoff@infradead.org>

Dockerfile-release.arm64

@@ -0,0 +1,11 @@
+FROM aarch64/ubuntu:16.04
+
+ADD etcd /usr/local/bin/
+ADD etcdctl /usr/local/bin/
+ADD var/etcd /var/etcd
+ADD var/lib/etcd /var/lib/etcd
+
+EXPOSE 2379 2380
+
+# Define default command.
+CMD ["/usr/local/bin/etcd"]

Dockerfile-release.ppc64le

@@ -2,8 +2,8 @@ FROM ppc64le/ubuntu:16.04
 
 ADD etcd /usr/local/bin/
 ADD etcdctl /usr/local/bin/
-RUN mkdir -p /var/etcd/
-RUN mkdir -p /var/lib/etcd/
+ADD var/etcd /var/etcd
+ADD var/lib/etcd /var/lib/etcd
 
 EXPOSE 2379 2380
 

scripts/build-docker

@@ -1,13 +1,16 @@
 #!/usr/bin/env bash
 
+set -e
+
 if [ "$#" -ne 1 ]; then
 	echo "Usage: $0 VERSION" >&2
 	exit 1
 fi
 
+VERSION=${1}
 ARCH=$(go env GOARCH)
 DOCKERFILE="Dockerfile-release"
-TAG="quay.io/coreos/etcd"
+: ${TAG:="quay.io/coreos/etcd"}
 
 if [ -z ${BINARYDIR} ]; then
 	RELEASE="etcd-${1}"-`go env GOOS`-`go env GOARCH`
@@ -24,17 +27,18 @@ fi
 
 if [ ${ARCH} != "amd64" ]; then
 	DOCKERFILE+=".${ARCH}"
-	TAG+="-${ARCH}"
+	VERSION+="-${ARCH}"
 fi
 
 BINARYDIR=${BINARYDIR:-.}
 BUILDDIR=${BUILDDIR:-.}
 
 IMAGEDIR=${BUILDDIR}/image-docker
 
-mkdir -p ${IMAGEDIR}
+mkdir -p ${IMAGEDIR}/var/etcd
+mkdir -p ${IMAGEDIR}/var/lib/etcd
 cp ${BINARYDIR}/etcd ${BINARYDIR}/etcdctl ${IMAGEDIR}
 
 cat ./${DOCKERFILE} > ${IMAGEDIR}/Dockerfile
 
-docker build -t ${TAG}:${1} ${IMAGEDIR}
+docker build -t ${TAG}:${VERSION} ${IMAGEDIR}