Dockerfile

Dockerfile
dockerfile manuals:
https://takacsmark.com/dockerfile-tutorial-by-example-dockerfile-best-practices-2018/
best practice:
https://docs.docker.com/develop/develop-images/dockerfile_best-practices/
key instructions
FROM - base image
ENV variable=test
environment variable
can be used with bash syntax 
$variable
VOLUME [ "/var/test" ]
used to expose some storage
CMD
what command should be run in the image
CMD [“executable”, “param1”, “param2”, ...]
Its possible to override the command on starting up a container 
docker run myImage:latest _command_
Only last 
CMD will be used (so specifiy only one).
Its a good practice to specify at leaset  a shell command here.
ENTRYPOINT
Used to specify the 'main executable' of the image
If 
ENTRYPOINT is specified, 
CMD paramas will be added to the 
ENTRYPOINT
ENTRYPOINT ["git"]
CMD ["--help"]
building
Docker CLI