Hi I finally managed to create an image from sourcecode. Some of it with help of this post:
https://forums.rocket.chat/t/how-to-build-a-rocket-chat-docker-image/3035
and following next steps:
First download source code and get in that folder, then:
1- cd /apps/meteor
2- meteor build --server-only --directory /tmp/rc-build (the lasta argument will be the path where you want the bundle to be created)
3- cp .docker/Dockerfile /tmp/rc-build (Modify Dockerfile acording to your needs)
4- cd /tmp/rc-build
5- docker build . -t someimage (name you want to give to your image)
Here I got stucked because I was starting mongodb in a different container and couldn’t link them up, I mean I could not make my rocket chat image to use mi mongo container runing, so i decided to launch them together as follows
6- While being in same folder, Create a docker-compose.yml (this will be similar to the one provided by rocketchat itself (check Documentation or here the docker-compose.yml-example )
7- docker-compose up -d (will launch your rocket attached to the mongo container)
I hope this helps