Set pm2 as default command in docker build

.. and overwrite in docker-compose. Move layer COPY as far as possible
to the end for faster rebuild.

Author: roschaefer

Dockerfile

@@ -1,6 +1,11 @@
 FROM node:8.9-alpine
 LABEL Description="This image is used to start the hc-api-feathers" Vendor="Human-Connection gGmbH" Version="1.0" Maintainer="Human-Connection gGmbH ([email protected])"
 
+# expose the app port
+EXPOSE 3030
+# chrome debugging
+EXPOSE 9229
+
 # update unix packages
 RUN apk update && apk upgrade
 RUN rm -rf /var/cache/apk/*
@@ -17,10 +22,10 @@ RUN yarn install --frozen-lockfile --non-interactive
 
 # copy the code to the docker image
 COPY . /API
-
 # setup local configuration
 COPY ./config/docker/* /API/config/
 
-# expose the app port
-EXPOSE 3030
-EXPOSE 9229
+# start the application in a autohealing cluster
+# NOTE: quick fix for server issues, restart api when reaching max of 300 MB Memory Usage (happens in conjunction with 100% CPU Usage)
+# TODO: find better way of dealing with that issue
+CMD ["pm2", "start", "server/index.js", "-n", "api", "--attach", "--max-memory-restart", "1024M"]