LGTM

LGTM

cherry picked into #15091

Back from holiday, so here is my review:

There is a group of options that is both contained in the output of docker --help and docker daemon help:

-D, --debug=false                    Enable debug mode
-H, --host=[]                        Daemon socket(s) to connect to
-l, --log-level=info                 Set the logging level
--tls=false                          Use TLS; implied by --tlsverify
--tlscacert=~/.docker/ca.pem         Trust certs signed only by this CA
--tlscert=~/.docker/cert.pem         Path to TLS certificate file
--tlskey=~/.docker/key.pem           Path to TLS key file
--tlsverify=false                    Use TLS and verify the remote

Are these options really supported in both positions? That means they could be legally specified twice, e.g.

docker -l info daemon -l debug

Completion only supports these options for docker, not docker daemon.
If the options are legal in both positions, I will add them.

cc @thaJeztah

@albers they are not legal, it will error out.

@albers as in, docker --tls run ... is legal, docker daemon --tls is legal, but docker --tls daemon --tls is not. I just don't know how to describe that.

EDIT: also, there is no way you can prevent the user from this: if it autocompletes to use --tls after docker, then it would be confusing to disallow daemon, they'd be like "wait why is there no daemon command" ? I'd much rather let them do docker --tls daemon --tls and learn that it's incorrect.

@tiborvass I see. So the new syntax would be docker daemon --tls and docker --tls is just for compatibility. As far as there is no conflict, the latter syntax works.

@albers Well, docker --tls is not for backwards compat (we don't want backwards compat in a bash completion script), it's for docker client commands (all except daemon).

@tiborvass I thing I got it: The above mentioned options are valid for all client commands as global options, i.e. they must be given right behind docker, e.g. docker --log-level debug run.

For docker daemon, these options are command options, i.e. they have to follow the command, e.g. docker daemon --log-level debug. For this one command, the global syntax is invalid and errors out. Example: docker --log-level debug daemon is invalid.

@albers correct

@tiborvass Thanks for your patience. I'm a bit in a hurry to finish up the completion.

So I will add support for the global options to docker daemon as command options as they are currently missing there.

@albers okay sorry about that, I'm really not good at these completion scripts. Thanks for your help!

@tiborvass Well, I'm sorry that completion bounced back to you because I was on holiday. Thanks for taking care of it!

@tiborvass By the way, I found that docker --log-level debug daemon errors out with

invalid flag '-l'.

Is this framework related or can this be fixed?

I'm sorry that completion bounced back to you because I was on holiday. Thanks for taking care of it!

@albers please don't feel sorry. We were aware you didn't have time, and you're always helping out in fantastic ways. There's more in life than Docker and you deserve your Holidays, no stress (really!) ❤️