What is workdir in overlay volume mounts?

[rEnr3n]

$ podman --version   
podman version 4.2.0

I ran the following commands trying to understand it:

$ mkdir dir1
$ mkdir dir2
$ podman run -it --rm -v dir1:/dir1:O,upperdir=$PWD/dir2,workdir=$PWD/dir1 alpine

# pwd
/
# exit

$ podman run -it --rm -v dir1:/dir1:O,upperdir=$PWD/dir2,workdir=/dir1 alpine 
Error: crun: mount `/home/ren/.local/share/containers/storage/overlay-containers/74ce44508f0277aee0df1835f9e2ab215d8e6ad4a7bf17652697c99da444f356/userdata/overlay/3196682081/merge` to `/dir1`: No such file or directory: OCI runtime attempted to invoke a command that was not found

$ podman run -it --rm -v dir1:/dir1:O,upperdir=$PWD/dir2,workdir=$PWD/dir2 alpine
Error: OCI runtime error: crun: mount `/home/ren/.local/share/containers/storage/overlay-containers/dbaae967c563fdf44ea92590ee75b0316a9fa0b5092188dc4b3c17fcf6547357/userdata/overlay/613033634/merge` to `/dir1`: Invalid argument

I assumed the workdir here is the same as --workdir. Or is it different?

[mheon]

@rhatdan @flouthoc PTAL

[rhatdan]

--workdir is the default directory inside of the container to place the init process in. IE Current Working Directory
workdir from an Overlay perspective is something different, it is the working directory for the kernel to place content in. I think this directory has to be empty. upperdir will contain content that is written to the upperlevel of the overlay. workdir content is not defined for overlay.

[flouthoc]

@rEnr3n , This is correct #15405 (reply in thread) , --workdir is different from overlay's advanced option workdir=. Overlay's workdir options is used to prepare files before they are switched to the overlay destination in an atomic action while podman's --workdir is completely different option as @rhatdan stated in above comment.

Both options are completely different and not directly related to each other.