Regression: Output formatting no longer supports join (Go template)

[matusmarhefka]

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

/kind bug

Description

Podman (v2.2.1) no longer supports join Go template when formatting output using --format. This is a regression compared to older podman (e.g. in F31). I haven't tested all Go templates from https://docs.docker.com/config/formatting/ so join might not be the only one which is not working.

Steps to reproduce the issue:

1. podman pull fedora

2. podman inspect fedora --format '{{join .Config.Env "\n"}}'

Describe the results you received:
ERRO[0000] Error printing inspect output: template: all inspect:1: function "join" not defined

Describe the results you expected:

DISTTAG=f33container
FGC=f33
container=oci

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

Output of podman version:

Version:      2.2.1
API Version:  2.1.0
Go Version:   go1.15.5
Built:        Tue Dec  8 09:37:50 2020
OS/Arch:      linux/amd64

Package info (e.g. output of rpm -q podman or apt list podman):

podman-2.2.1-1.fc33.x86_64

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

Yes, latest released in Fedora 33.

Additional information:

On Fedora 31 this works as expected:

# podman inspect fedora --format '{{join .Config.Env "\n"}}'
DISTTAG=f33container
FGC=f33
container=oci
# rpm -q podman 
podman-2.1.1-3.fc31.x86_64

[mheon]

@jwhonce PTAL

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[vrothberg]

@jwhonce @ashley-cui do you know what's going on?

[ashley-cui]

I don't know exactly where the problem is but I tested on podman 2.1 and it's definitely a regression. I haven't looked into the old code enough to know where join is handled, but its different than table - table is table {{.Name}} whereas join is {{join .Config.Env "\n"}}, inside the template itself

[jwhonce]

@ashley-cui I know what the issue is and will fix it. Short explanation, we no longer define a set of template functions.

[jwhonce]

c/common updated with containers/common#426
podman will need to vendor in this update.

[jwhonce]

#9196 should have included fix in podman