Docker optimizations

[iCesofT]

With these optimizations, instead of:

REPOSITORY                                             TAG                    IMAGE ID            CREATED             SIZE
onesaitplatform/cache-server                           latest                 5f2910a27f25        2 minutes ago       208MB
onesaitplatform/api-manager                            latest                 23fb79da0c3e        2 minutes ago       419MB

we are getting:

REPOSITORY                                             TAG                    IMAGE ID            CREATED             SIZE
onesaitplatform/cache-server                           latest                 636b516dbe7d        11 seconds ago      174MB
onesaitplatform/api-manager                            latest                 4034b7636e5d        34 seconds ago      399MB

And also we add Java memory optimizations (see: http://icesoft.blog/2018/05/25/java-memory-optimized-docker-image/). Maybe you could have your own onesait Java docker image (i.e.: https://hub.docker.com/r/fjahijado/java/)

[mmorancassy]

Hi @iCesofT !

Thanks for your contribution! :) we see interesting points on it, but we cannot accept entirely to merge it in the Platform master branch.

• Anyway, if you do some contributions, even minor contributions, please change it and do it separetely, eg: pom.xml formatting, do it in other pull request, README.md dots added at the end of the lines, in other pull request, and finally, Dockerfile contributions in other pull request. eg: if you do a new pull request with FROM changes (jre instead of jdk) we'll accept it :)

• RUN instructions, we have independent/isolated RUN for user creation cause this layer is shared between all Platform images.

• Finally, JRE improvements, we have doubts about it, eg: UnlockExperimentalVMOptions or java.awt.headless... we need to test it before in our OP modules, eg: semantic information broker has different perfomance requirements than controlpanel web app

We have check it out your Custom JRE image https://hub.docker.com/r/fjahijado/java/dockerfile and we think is a good idea :) probably we'll work on it

Great work! please continue contribute to the platform 👍

Kind Regards Miguel.M