podman run: exit status 126/127 seem to be reversed in sense

[edsantiago]

podman-run(1) asserts that it will exit with 126 if command cannot be invoked (e.g. permission denied), and 127 if the command cannot be found. I believe the test sense in cmd/podman/run.go:83-86 is reversed:

# podman run --rm registry.access.redhat.com/rhel7/rhel:latest /etc;echo $?
container create failed: container_linux.go:348: starting container process caused "exec: \"/etc\": permission denied"
: internal libpod error
127

# podman run --rm registry.access.redhat.com/rhel7/rhel:latest nonexistent-command;echo $?
container create failed: container_linux.go:348: starting container process caused "exec: \"nonexistent-command\": executable file not found in $PATH"
: internal libpod error
126

[mheon]

This sounds like https://github.com/projectatomic/libpod/blob/5529143877778ef8bcdd05179e279bb7d662b431/cmd/podman/run.go#L81-L87

Either the error codes are switched in the code or in the manpages. We should fix whichever breaks with Docker convention.

[edsantiago]

My bad: I meant to include this: docker is the opposite. That is: I believe the podman documentation should remain as-is, and the code itself should be adjusted.

As long as I'm blabbing, though: I'm not sure if grepping for "permission denied" is the best way to implement this. There may be other reasons why a command cannot be invoked. I can't think of any offhand, though, and don't have a better suggestion atm.

[mheon]

I tend to agree that manually manipulating the error seems like a bad idea. It might be a good idea to expose more explicit error codes of of libpod so we have a better idea of what's going on

[mheon]

I'm also far from certain ctr.Init() erroring means the command did not exist, given that Init failure could also be issues with storage and mounts.

[rhatdan]

The convention that is followed in the chroot command.

info chroot
...
     125 if ‘chroot’ itself fails
     126 if COMMAND is found but cannot be invoked
     127 if COMMAND cannot be found
     the exit status of COMMAND otherwise

[rhatdan]

Permission denied should be 126

SO they are reversed.

[baude]

Fixed!