podman search: --list-tags clobbers --format

[edsantiago]

podman search --list-tags will output a table, even if --format is requested (either json or {{.Tag}}):

$  ./bin/podman search --list-tags --format json quay.io/podman/stable
NAME                   TAG
quay.io/podman/stable  v1.4.4
quay.io/podman/stable  v1.4.2
...

If possible, the requested --format should be honored. If not possible, there should be a run-time check throwing a conflicting-options error.

Related: #8276

[yufeifly]

Hi, I am using podman 2.1.1. When I run command podman search --list-tags --format json quay.io/podman/stable, I get this output Error: unknown flag: --list-tags. Is this due to the podman version?

[rhatdan]

Looks like this did not show up until podman-2.2, which should be available now.

[Afourcat]

Hello,
I was trying to fix this issue, but what kind of output are you waiting for?

This output following the same structure of the default option of the podman search command:

{
    "Index": "",
    "Name": "docker.io/library/redis",
    "Description": "",
    "Stars": 0,
    "Official": "",
    "Automated": "",
    "Tag": "2.8.7"
}

Or this output following the structure of the podman search --list-tags command:

{
    "Name": "docker.io/library/redis",
    "Tag": "2.8.7"
}

Thank you for your time and your work.

[edsantiago]

That's a really good question. My first reaction was to go with your first option (populate Tag, leave all other fields the same)... but after thinking about it that just isn't meaningful. Your second option is more natural. One followup suggestion, what would you think of:

{
    "Name": "docker.io/library/redis",
    "Tags": ["2-32bit", "2.6-32bit", "2.6.17-32bit", "2.6.17", "2.6", "..."]
}

Name is useful to canonicalize an input arg, e.g. docker.io/redis would be returned as .../library/redis. Tags is explicitly plural to prevent naïve code from accessing Tag as a scalar; it's also more intuitive given the name of the --list-tags option.

I haven't even peeked at the code, and don't know how easy/hard that would be; nor do I know if this would violate API conventions. @rhatdan @mheon @jwhonce @TomSweeneyRedHat @baude WDYT?

[Afourcat]

If it does not violate any conventions, Your suggestion seems better.

For me, the implementation looks feasible. It looks like it could be fixed in this file.

I will implement your output format, and when the community validates that it follows all necessary conventions, I will make a pull request. If it sounds right to you.