Command to show tags in a repository

[qweeah]

The proposed command is:

Usage:
  oras repository show-tags REPO [flags]

Flags:
  --ca-file string           server certificate authority file for the remote registry
  -d, --debug                    debug mode
  -h, --help                     help for showing tags
      --insecure                 allow connections to SSL registry without certs
  -p, --password string          registry password or identity token
      --password-stdin           read password or identity token from stdin
      --plain-http               allow insecure connections to registry without SSL check
  -u, --username string          registry username
  -v, --verbose                  verbose output

The output should be a list of tags with one tag per line.

Related to #459

[junczhu]

I am interest in this, please assign this issue to me

[sajayantony]

Recommend keeping this consistent and using list-tags instead of show-tags if we want to keep this command under repository.

Why don't we move these directly under oras and have oras list-tags and oras list-repositories or oras catalog -

Basically this is in continuation of the discussion for #470

[FeynmanZhou]

@oras-project/oras-maintainers

IMO, show tags defaults to the repository level, which means it is not necessary to add a noun (root command) repository here.

Considering we will provide a new group tag in ORAS CLI 0.15, I would suggest putting show tags under the tag group directly and using tag list like the following sample CLI UX. This looks more intuitive to me:

$ oras tag list library/alpine
3.10.0
3.10.1
3.10.2
3.10.3

[sajayantony]

How would you differentiate the adding tag command?

[junczhu]

For your information, here is the sample output of this command:

/cc @FeynmanZhou