ref(tests/etcdutils): optimize test-etcd Dockerfile

Reduces the virtual size of "deis/test-etcd" from 467.4MB to 200.8MB.

Author: mboersma

tests/etcdutils/Dockerfile

@@ -1,18 +1,21 @@
 FROM ubuntu:12.04
-MAINTAINER Matt Boersma <matt@opdemand.com>
 
-# Install prerequisites: wget, git, and go.
-RUN apt-get update -q && DEBIAN_FRONTEND=noninteractive apt-get install -qy wget git-core
-RUN wget -qO- https://storage.googleapis.com/golang/go1.3.1.linux-amd64.tar.gz | tar -C /usr/local -xz
-ENV PATH /usr/local/go/bin:$PATH
-
-# Build etcd v0.4.6. Keep this in sync with Deis' version.
-RUN git clone -q https://github.com/coreos/etcd.git /opt/etcd
-RUN cd /opt/etcd && git checkout -q v0.4.6 && ./build
-
-# Download latest stable etcdctl. Keep this in sync with Deis' version.
+# Download etcdctl binary -- keep in sync with CoreOS' version.
 ADD https://s3-us-west-2.amazonaws.com/opdemand/etcdctl-v0.4.6 /usr/local/bin/etcdctl
 RUN chmod +x /usr/local/bin/etcdctl
 
+# build etcd and then clean up
+RUN buildDeps='curl git-core'; \
+    set -x; \
+    export DEBIAN_FRONTEND=noninteractive; \
+    apt-get update && apt-get install -y $buildDeps --no-install-recommends \
+    && curl -sSL https://storage.googleapis.com/golang/go1.3.1.linux-amd64.tar.gz | tar -C /usr/local -xz \
+    && git clone -q https://github.com/coreos/etcd.git /opt/etcd \
+    && cd /opt/etcd && git checkout -q v0.4.6 && PATH=/usr/local/go/bin:$PATH ./build \
+    && cp /opt/etcd/bin/etcd /usr/local/bin \
+    && cd && rm -rf /usr/local/go /opt/etcd \
+    && apt-get purge -y $buildDeps \
+    && apt-get autoremove -y && apt-get clean
+
 EXPOSE 4001 7001
-CMD ["/opt/etcd/bin/etcd"]
+CMD ["/usr/local/bin/etcd"]