[BUG]: DNS issues with resolv.conf as a symlink (networkmanager/systemd-resolve)

[noideaman]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

when running elevate on almalinux 9 to 10 i had dns issues with preupgrade

it could not find any repos including baseos

Expected Behavior

elevate should resolve addresses

Steps To Reproduce

1. install elevate
2. make sure /etc/resolv.conf is a symlink managed either by networkmanager or systemd-resloved
3. run leaap preupgrade
4. get the error that a repo like 'https://mirrors.almalinux.org/mirrorlist/10.1/baseos' could not be resolved

Anything else?

current fix is to remove the symlink and set dns manually in a new resolv.conf file

Search terms

dns, resolv

[yuravk]

Greetings @noideaman

Thank you for reporting the issue.

I can confirm the leapp preupgrade fails if /etc/resolv.conf -> /run/systemd/resolve/resolv.conf with the:

Error: Failed to download metadata for repo 'almalinux10-baseos': Cannot prepare internal mirrorlist: Curl error (6): Couldn't resolve host name for https://mirrors.almalinux.org/mirrorlist/10.1/baseos [Could not resolve host: mirrors.almalinux.org]

But I had to create the symlink manually. So, did you create it manually or it's probably cloud-init related thing or something ?

[yuravk]

The issue is a symlink-vs-tmpfs ordering conflict between the source overlay and systemd-nspawn( if we a considering the situation /etc/resolv.conf -> /run/systemd/resolve/resolv.conf).

/run (which is a tmpfs) is not given its own separate overlay, and systemd-nspawn mounts a fresh tmpfs on /run. This wipes out the host's /run/systemd/resolve/resolv.conf. /etc/resolv.conf is still a symlink to /run/systemd/resolve/resolv.conf, but that path no longer exists - dangling symlink.

The other thing is, I can't get the symlink is created automatically (by service or something, not manually). So for now it's not clear this should be fixed or reported upstream.