Help understanding permissions

[realSConway]

Hi folks,

I need help/assistance on why a file is not accessible to another rootless container running in same pod.

The two projects im using are:

• osminogin/docker-tor-simple
• kylemanna/bitcoind

Warning in question is found in btc debug.log:
Authentication cookie /var/lib/tor/control_auth_cookie could not be opened (check permissions)

Containers are run as:

podman run --rm --name tor --pod bitcoin --volume ./tor:/var/lib/tor:z --volume ./tor/torrc:/etc/tor/torrc:ro osminogin/tor-simple

podman run --rm --name btc --pod bitcoin --volume ./bitcoin:/bitcoin/.bitcoin:z kylemanna/bitcoind

tor has following user/group:

podman exec -ti tor id
uid=100(tor) gid=65533(nogroup) groups=65533(nogroup)

and btc:

podman exec -ti btc id
uid=0(root) gid=0(root) groups=0(root)

permissions to ./tor

ls -l ./tor
total 11544
-rw-------. 1 100099 165532      51 Feb 16 20:38 .ash_history
-rw-------. 1 100099 165532   18209 Feb 16 20:20 cached-certs
-rw-------. 1 100099 165532 2218992 Feb 16 20:20 cached-microdesc-consensus
-rw-------. 1 100099 165532 9533971 Feb 16 20:23 cached-microdescs
-rw-------. 1 100099 165532    7573 Feb 16 20:23 cached-microdescs.new
-rw-r-----. 1 100099 165532      32 Feb 16 20:54 control_auth_cookie
drwx------. 1 100099 165532       0 Feb 16 20:20 keys
-rw-------. 1 100099 165532       0 Feb 16 20:54 lock
-rw-------. 1 100099 165532   13977 Feb 16 21:23 state
-rw-r--r--. 1 100099 165532    9035 Feb 16 17:49 torrc

I've tried mounting tor volume (./tor:/var/lib/tor) with :z, :Z :z,U --group-add keep-groups or with -e PUID=100 but error is still logged.

podman unshare chown 100: ./tor did nothing either.

Shouldn't a uid 0 be able to read/write to a uid 100?

Any pointers would be greatly appreciated

[Luap99]

maybe https://www.redhat.com/sysadmin/debug-rootless-podman-mounted-volumes and https://www.redhat.com/sysadmin/container-permission-denied-errors will help