switched to building haproxy from source adding prometheus exporter. …

…also switched to multistage building to reduce image size

Dockerfile

@@ -1,14 +1,26 @@
-FROM ubuntu:18.04
+FROM ubuntu:18.04 AS buildstage
 
 MAINTAINER arthur@caranta.com
 ENV DEBIAN_FRONTEND noninteractive
 ENV INITRD No
 
 RUN apt-get update -y
 RUN apt-get install --force-yes -y haproxy inotify-tools python-pip curl lua-socket lua-json lua-http && \
-    pip install envtpl supervisor supervisor-logging && \
-    apt-get -y remove build-essential ".*-dev" && \
-    apt-get -y autoremove
+    pip install envtpl supervisor supervisor-logging
+
+#Fetch and build haproxy from github, compile it with prometheus exporter
+RUN cd /tmp && \
+    apt install -y git ca-certificates gcc libc6-dev liblua5.3-dev libpcre3-dev libssl-dev libsystemd-dev make wget zlib1g-dev && \
+    git clone https://github.com/haproxy/haproxy.git && \
+    cd haproxy && \
+    make TARGET=linux-glibc USE_LUA=1 USE_OPENSSL=1 USE_PCRE=1 USE_ZLIB=1 USE_SYSTEMD=1 EXTRA_OBJS="contrib/prometheus-exporter/service-prometheus.o" && \
+    make install-bin && \
+    cp /usr/local/sbin/haproxy /usr/sbin/haproxy && \
+    cd / && rm -rf /tmp/haproxy
+
+RUN apt-get -y remove build-essential ".*-dev" git gcc make && \
+    apt-get -y autoremove && \
+    rm -rf /var/lib/apt/lists/* /var/cache/apt/*
 
 ADD . /app
 WORKDIR /app
@@ -21,6 +33,16 @@ RUN cp /app/lua/haproxy-lua-http.lua /usr/share/lua/5.3/haproxy-lua-http.lua
 #Source : https://raw.githubusercontent.com/TimWolla/haproxy-auth-request/master/auth-request.lua
 RUN cp /app/lua/auth-request.lua /etc/haproxy/auth-request.lua
 
+#Multistage build
+FROM scratch
+
+COPY --from=buildstage / /
+
+WORKDIR /app
+
+MAINTAINER arthur@caranta.com
+ENV DEBIAN_FRONTEND noninteractive
+ENV INITRD No
 ENV TPLFILES /etc/supervisor/supervisord.conf
 ENV HASVC hapconf.cfg
 ENV SYSLOG_SERVER 127.0.0.1