support auth to multiple regs in secret file

[rbauduin]

I saw you merged my previous PR while I was finalizing this. It makes it possible to have all authentication info in a docker secret file, and it also allows authenticating to one registry with different accounts. This last point requires the container to be updated to be labeled accordingly to identify which authentication information to use. See the README changes for details. Let me know what you think, it works fine for me.

[djmaze]

@rbauduin Sorry, would you mind rebasing? I just fixed all issues reported by shellcheck on the codebase.

[rbauduin]

I didn't have the time to test correctly the last changes, but that way you can already have a look.

[rbauduin]

FYI I've deployed it and am using it successfully

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[rbauduin]

@djmaze : no interest in this?

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[rbauduin]

Maybe we can sync to get it merged?

[djmaze]

And there's a conflict again.. sorry

[djmaze]

@rbauduin Thanks, and sorry for the long wait!