[lxc-users] Better error logging when starting containers?

[John Siu]

I agree that lxc-start need better error logging, not only for lxc-start, but for most lxc-* tools. But on the other hand, dev properly are too busy straighten out other issue for lxc v2.

Regarding your issue, you can try following:

	lxc-start-ephemeral -n e1 -l 9 -o test -d

The “-l 9” (lower-case L) set the log level to 9. That should give you more information. Without it the log level is default to 0 or 1, which is the same as what you see on screen (stderr).

John Siu


> On Feb 21, 2016, at 18:50, Akshay Karle <akshay.a.karle at gmail.com> wrote:
> 
> Hello lxc users,
> 
> After having used lxc for a while now, I've realized that when the container fails to start, it fails with a very generic message as follows:
> 
> $ lxc-start -n test
> lxc-start: lxc_start.c: main: 344 The container failed to start.
> lxc-start: lxc_start.c: main: 346 To get more details, run the container in foreground mode.
> lxc-start: lxc_start.c: main: 348 Additional information can be obtained by setting the --logfile and --logpriority options.
> 
> And if you are using ephemeral containers, the error is even more generic and with no way to increase the log level:
> 
> $ lxc-start-ephemeral -n e1 -o test -d
> setting rootfs to .%s. /home/vagrant/.local/share/lxc/e1/rootfs
> The container 'e1' failed to start.
> 
> I was wondering if someone felt the need of having a little more meaningful error messages giving a summary of the error in the console output. The container logfile does have way more descriptive error messages, but since you don't directly have the errors in the console output, you are forced to open the logfiles everytime something goes wrong. Instead if you had an output that just included a few important error lines from the logfile such as the following example:
> 
> $ lxc-start -n test
> lxc-start: lxc_start.c: main: 344 The container failed to start.
> lxc_start - start.c:lxc_spawn:1031 - failed creating cgroups
> lxc-start: lxc_start.c: main: 346 To get more details, run the container in foreground mode.
> lxc-start: lxc_start.c: main: 348 Additional information can be obtained by setting the --logfile and --logpriority options.
> 
> Do you think this would help? Although I have no idea if this is simple to implement, I just wanted to get your ideas, suggestions and concerns (if any) before attempting to figure out a solution.
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