can not have JSON format output of cli "podman search" or "podman image search"

[Edward5hen]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description
It seems we can't have the image search result in a JSON format now. I suppose it can be done by using a command like podman search --format json $IMAGE or podman image search --format json $IMAGE, but I got several lines of the string "json" instead.

Steps to reproduce the issue:

1. podman search --format json registry.fedoraproject.org/fedora or podman image search --format json registry.fedoraproject.org/fedora

Describe the results you received:
❯ podman search --format json registry.fedoraproject.org/fedora
json
json
json
json
json
json
json
json

❯ podman image search --format json registry.fedoraproject.org/fedora
json
json
json
json
json
json
json
json

Describe the results you expected:
Display all the registries in a JSON format.

Additional information you deem important (e.g. issue happens only occasionally):
Always

Output of podman version:

❯ podman version
Version:      2.2.0-dev
API Version:  2.0.0
Go Version:   go1.14.9
Git Commit:   e2b82e6245ed9459a37dc004a2b1d593d2835cb7
Built:        Sun Nov  8 23:41:04 2020
OS/Arch:      linux/amd64

Have you tested with the latest version of Podman and have you checked the Podman Troubleshooting Guide?

Yes

Additional environment details (AWS, VirtualBox, physical, etc.):

[Edward5hen]

For other random string value of argument --format, it will just print out the strings too.
❯ podman image search --format random registry.fedoraproject.org/fedora
random
random
random
random
random
random
random
random

[Luap99]

The format flag expects a go template: --format string Change the output format to a Go template

For example:

podman search --format "{{.Name}}" registry.fedoraproject.org/fedora
registry.fedoraproject.org/f29/fedora-toolbox
registry.fedoraproject.org/f30/fedora-toolbox
registry.fedoraproject.org/f31/fedora-toolbox
registry.fedoraproject.org/f32/fedora-toolbox
registry.fedoraproject.org/f33/fedora-toolbox
registry.fedoraproject.org/f34/fedora-toolbox
registry.fedoraproject.org/fedora
registry.fedoraproject.org/fedora-minimal

[Luap99]

I will open a PR to add json support.

[jwhonce]

For other random string value of argument --format, it will just print out the strings too.
❯ podman image search --format random registry.fedoraproject.org/fedora
random
random
random
random
random
random
random
random

@Edward5hen That is expected behavior. The value of --format is fed to the Go template library.