debian-stretch and overall smaller image size

Dockerfile

@@ -1,21 +1,21 @@
-FROM ubuntu:17.10 as wrk2-builder
+FROM debian:stretch-slim as wrk2-builder
 MAINTAINER [email protected]
 
 RUN apt-get update
-RUN apt-get install -y lua-json wget unzip build-essential libssl-dev
+RUN apt-get install -y lua-json wget unzip build-essential libssl-dev zlib1g-dev
 RUN wget -O /tmp/wrk2.zip 'https://github.com/giltene/wrk2/archive/master.zip'
 RUN unzip /tmp/wrk2.zip -d /tmp/
 RUN make -C /tmp/wrk2-master
 
-FROM python:3.6
+FROM python:3.7-slim
 RUN apt-get update \
- && apt-get install -y lua-json libssl1.0.0 jq \
+ && apt-get install -y lua-json libssl1.0.2 jq \
  && apt-get clean
 
 COPY --from=wrk2-builder /tmp/wrk2-master/wrk /usr/bin/wrk2
 
 COPY requirements.txt /graphql-bench/requirements.txt
-RUN pip install -r /graphql-bench/requirements.txt
+RUN pip install --no-cache-dir -r /graphql-bench/requirements.txt
 
 COPY bench.py /graphql-bench/bench.py
 COPY plot.py /graphql-bench/plot.py