Connection parameters can only be passed on the command line

[mraspaud]

Feature Request

Is your feature request related to a problem? Please describe.
At the moment, it it not possible to pass the address to listen to in the configuration file (product list). Instead, the address can only be configured with the -a flag on the command line of the satpy laucher.

Describe the solution you'd like
I would like to be able to have the connection parameters in the config file.

Describe any changes to existing user workflow
That will allow to have static scripts/entrypoints to launch trollflow2 and pass the address to connect to only in the config file.

[pnuu]

I've used an environment variable in my container entrypoint and have injected it when starting the container to work around this. I don't remember why I didn't search for a better solution by changing the actual code.

[mraspaud]

Yes, I know, but I still consider we should do something about it.