Merge pull request 'massive image size reduction' (#2) from multistage into master

Reviewed-on: #2

Dockerfile

@@ -1,13 +1,22 @@
-#Dockerfile for a Postfix email relay service
-FROM alpine:3
+FROM alpine:3 as bridgebuild
 #MAINTAINER Juan Luis Baptiste juan.baptiste@gmail.com
 MAINTAINER finn git@hot.oily.dad
 
+
+# ProtonMailBridge Build
+RUN apk add make go pkgconfig libsecret libsecret-dev git bash
+WORKDIR /
+RUN git clone https://github.com/ProtonMail/proton-bridge.git pmb
+WORKDIR /pmb
+RUN echo "BUILDING BRIDGE"
+RUN make build-nogui
+
+#Postfix email relay service
+FROM alpine:3
 RUN apk update && \
     apk add bash gawk cyrus-sasl cyrus-sasl-login cyrus-sasl-crammd5 mailx \
     postfix && \
-    apk add make go pkgconfig libsecret libsecret-dev git gpg gpg-agent pass && \
-    apk add msmtp && \
+    apk add libsecret gpg gpg-agent pass msmtp && \
     rm -rf /var/cache/apk/* && \
     mkdir -p /var/log/supervisor/ /var/run/supervisor/ && \
     sed -i -e 's/inet_interfaces = localhost/inet_interfaces = all/g' /etc/postfix/main.cf
@@ -27,12 +36,9 @@ COPY run.sh /
 RUN chmod +x /run.sh
 RUN newaliases
 
-# ProtonMailBridge
-RUN git clone https://github.com/ProtonMail/proton-bridge.git pmb
+# pmb
+COPY --from=bridgebuild /pmb /pmb
 WORKDIR pmb
-RUN echo "BUILDING BRIDGE"
-RUN make build-nogui
-RUN rm -rf /root/.cache && rm -rf /root/go
 
 EXPOSE 25
 #ENTRYPOINT ["/run.sh"]