[systemd-devel] Trying to get journalctl -M UUID to work with docker containers

[Lennart Poettering]

On Mon, 08.02.16 09:21, Daniel J Walsh (dwalsh at redhat.com) wrote:

> Is there a way for me to see the settings of _MACHINE_ID and _BOOT_ID?  Also how can I see the actual path to the file journalctl is 
> reading?  

Use "journalctl -o verbose".

If "-M" is passed to journalctl it should only read files from the
/var/log/journal in the journal root directory. It will not read the
data from /run/log/journal. This means you have to enabled persistent
logging in the container for this to work currently (this is because
/var of the container is generally accessible from outside of it, via
the container's root directory. However, the /run directory is usually
a tmpfs mounted inside the container and not accessible at all from
outside).

There was some work on fixing this limitation, but this was never finished:

https://github.com/systemd/systemd/pull/49

Lennart

-- 
Lennart Poettering, Red Hat