Dockerfile optimizations (#70)

* Optimize final image build size by grouping commands in the same build step and deleting unneeded package installation files. Add non-interactive env vars.

* Add non-interactive env vars to builder apt-get. Readability.

* apt-get switches: be less forceful to allow detection of potentially harmful build errors.

* Add '--no-install-recommends' switch to apt-get command to reduce build time and make image smaller (#70).

Author: pataquets

Dockerfile

@@ -1,13 +1,24 @@
 FROM ubuntu:16.04 as builder
 RUN apt-get update
-RUN apt-get install -yy build-essential autoconf automake libpcre3-dev libevent-dev pkg-config zlib1g-dev git libboost-all-dev cmake flex
+RUN \
+  DEBIAN_FRONTEND=noninteractive \
+  apt-get install -y \
+    build-essential autoconf automake libpcre3-dev libevent-dev \
+    pkg-config zlib1g-dev git libboost-all-dev cmake flex
 RUN git clone https://github.com/RedisLabs/memtier_benchmark.git
 WORKDIR /memtier_benchmark
 RUN autoreconf -ivf && ./configure && make && make install
 
 FROM ubuntu:16.04
 LABEL Description="memtier_benchmark"
 COPY --from=builder /usr/local/bin/memtier_benchmark /usr/local/bin/memtier_benchmark
-RUN apt-get update
-RUN apt-get install -yy libevent-dev
+RUN \
+  apt-get update && \
+  DEBIAN_FRONTEND=noninteractive \
+    apt-get install -y --no-install-recommends \
+      libevent-dev \
+  && \
+  apt-get clean && \
+  rm -rf /var/lib/apt/lists/
+
 ENTRYPOINT ["memtier_benchmark"]