Question: why does /var/log/messages exist when running NixOS tests?

aanderse · October 3, 2018, 10:00am

Thought I’d cross post here to see if I can get an answer:

github.com/NixOS/nixpkgs

Question: why does /var/log/messages exist when running NixOS tests?

opened 12:32PM - 29 Sep 18 UTC

closed 11:40PM - 11 Oct 18 UTC

aanderse

0.kind: question

## Issue description rsyslogd & syslog-nd are broken on NixOS 18.09 because at …some point systemd stopped automatically forwarding messages to syslog. See explanation here: https://github.com/NixOS/nixpkgs/pull/47306 The fix for this should be simple enough and I have a working PR for it. The problem is that when running NixOS tests under qemu the file /var/log/messages seems to always exist. Why? /var/log/messages doesn't exist on any of the NixOS machines I run. On my system even when I turn rsyslogd on still nothing gets written to /var/log/messages unless I add ForwardToSyslog=yes to /etc/systemd/journald.conf. Why do the NixOS qemu images automatically write to /var/log/messages? How do they write there if ForwardToSyslog isn't added to journald.conf? I checked in the qemu machine and journald.conf does not contain ForwardToSyslog at all. Do these qemu images use a syslog instead of journald? I can't really write an effective test to ensure my code is working because a regular NixOS system is not reproducible in the qemu environment as far as whether /var/log/messages exists or not (what I'm testing for). Any help on this one? Thanks ### Steps to reproduce nix-build '<nixpkgs/nixos/tests/atd.nix>' -A driver ./result/bin/nixos-run-vms type "root" as a login name to the qemu machine that pops up ls /var/log/messages ## Technical details Please run `nix-shell -p nix-info --run "nix-info -m"` and paste the results. - system: `"x86_64-linux"` - host os: `Linux 4.14.72, NixOS, 18.09beta609.3768913cc9e (Jellyfish)` - multi-user?: `yes` - sandbox: `yes` - version: `nix-env (Nix) 2.1.1` - channels(root): `"nixos-18.09beta609.3768913cc9e"` - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

Thanks