[Pkg-nagios-devel] Bug#863797: Bug#863797: monitoring-plugins-basic: unable to use check_disk inside /var/tmp

[Bas Couwenberg]

On 2017-06-01 10:11, Emmanuel DECAEN wrote:
> Le 01/06/2017 à 07:21, Sebastiaan Couwenberg a écrit :
>> notfound 863797 nagios-nrpe/3.0.1-3
>> thanks
>> 
>> On 05/31/2017 11:05 PM, Emmanuel DECAEN wrote:
>>>> And what does nagios-nrpe-server log on the system where the 
>>>> check_disk
>>>> command you claim fails?
>>> May 31 22:46:45 server nrpe[31037]: Running command:
>>> /usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /var/tmp/mysql
>>> May 31 22:46:45 server nrpe[31037]: Command completed with return 
>>> code 2
>>> and output: DISK CRITICAL - /var/tmp/mysql is not accessible: No such
>>> file or directory
>>> May 31 22:46:45 server nrpe[31037]: Return Code: 2, Output: DISK
>>> CRITICAL - /var/tmp/mysql is not accessible: No such file or 
>>> directory
>>> 
>>> I think the problem is related to this "private" mount in
>>> nagios-nrpe-server (extract from /proc/xx/mountinfo):
>>> 121 113 8:5
>>> /tmp/systemd-private-b35c254c031041979d3126e02a0c5c51-nagios-nrpe-server.service-MbLbk1/tmp
>>> /var/tmp rw,relatime shared:66 master:28 - ext4 /dev/sda5 
>>> rw,data=ordered
>> The systemd configuration uses PrivateTmp=true, you can override it by
>> adding a snippet:
>> 
>>  /etc/systemd/system/nagios-nrpe-server.service.d/local.conf
>> 
>> With the following content:
>> 
>>  [Service]
>>  PrivateTmp=false
>> 
>> See systemd.exec(5) for details about PrivateTmp.
> 
> Thanks for the details.
> 
>> 
>> You have a non-standard setup, hence you need to customize the
>> configuration. This is not a bug in nagios-nrpe, so I'm closing this 
>> issue.
> 
> I disagree. Having a configuration using standard check_disk on any
> directory can't be considered as "a non-standard setup" (and especially
> when it was working correctly in Debian 8)

Your check_disk command is not standard, on Debian systems 
/var/tmp/mysql is not a standard directory.

/var/tmp and its subdirectories are either part of the / slice or a 
separate /var slice.

> Maybe, I'm missing something but there was no "PrivateTmp=true" in
> Debian 8 nagios-nrpe-server.
> From what I see, using "PrivateTmp=true" in nagios-nrpe-server is a
> *change in behavior from Debian 8 to Debian 9*.

NRPE 2.15 in jessie didn't support systemd, NRPE 3.0 in stretch does.

It is a change in behavior, but not a bug.

> I think, you can't indicate "not found" on this bug report as it can be
> easily reproduced, with a standard check_disk configuration.

It's not a bug, so I removed the affected version.

> Don't you think the package upgrade should warn user about this change
> when migrating from Debian 8 to Debian 9 ?

No. Standard setups don't have a separate /var/tmp/mysql partition, and 
will have /var/tmp as part of the root file system or separate /var. 
check_disk via NRPE works as expected on those systems.

You have a non-standard setup where you explicitly want to monitor a 
non-standard subdirectory of /var/tmp and so you need to customize your 
monitoring to work with your non-standard setup.

On one of my systems I have a separate /tmp and /var and there 
check_disk works just fine via NRPE 3.x with PrivateTmp=true.

Kind Regards,

Bas