Two Issues after fresh install

Hey guys,

I just did a fresh install using the instructions here:
https://docs.librenms.org/Installation/Installation-CentOS-7-Nginx/

The only error I have in /validation is regarding the Discovery error. I have tried updating librenms and rebooting however that has not fixed anything although I seem to have to fix the user permissions every time I run the updater. Not sure if thats normal.

Issue# 1

When I go to create a new device group.

I get “Whoops, looks like something went wrong. Check your librenms.log.” This happens in chrome and IE.

Issue #2 Fail: Discovery has never run. Check the cron job

Here are the errors I am getting in my librenms.log

https://p.libren.ms/view/3cffb2a4

Discovery pastebin:
https://p.libren.ms/view/4303a756

Poller pastebin:
https://p.libren.ms/view/5cd2d897

Thanks!

Do you actually have devices in the system that can be discovered via snmp?

Elias, Yeah it seems to be successfully monitoring a couple devices.

In this order:

  • Check the “librenms” user is in your www-data (or nginx/apache) group.
  • chmod g+w /opt/librenms/cache
  • if still no success you can fix it with this Manage group new device group fail

Please let us know which one worked as trying to isolate the issue.

Ahhh yes Issue #2 seems to have resolved itself after I added actual devices for librenms to monitor. That makes sense!

the librenms user was not in the nginx user group. I added it but it didnt fix the issue.

I ran * chmod g+w /opt/librenms/cache and that didnt work

I tried the commands in this link


but the commands dont work. I tried supplementing nginx for www-data and got “chown: cannot access ‘devices_relationships.cache’: No such file or directory”

ahh that file lives in /opt/librenms/cache/devices_relationships.cache

Do you see it in there?

if the file doesnt exist, look at the error in the librenms.log in /opt/librenms/logs

Chas, The file does not exist in /opt/librenms/cache/

Here is the error from librenms.log

[2019-07-17 11:54:02] production.ERROR: file_put_contents(/opt/librenms/cache/devices_relationships.cache): failed to open stream: Permission denied {“userId”:1,“exception”:"[object] (ErrorException(code: 0): fi$
[stacktrace]
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, ‘file_put_conten…’, ‘/opt/librenms/L…’, 173, Array)
production.ERROR: file_put_contents(/opt/librenms/cache/devices_relationships.cache): failed to open stream: Permission denied {“userId”:1,“exception”:"[object] (ErrorException(code: 0): fi$
[stacktrace]
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, ‘file_put_conten…’, ‘/opt/librenms/L…’, 173, Array)

next steps in this order.

  • chmod +x /opt/librenms/cache
  • work now?
  • touch /opt/librenms/cache/devices_relationships.cache
  • chown www-data:www-data /opt/librenms/cache/devices_relationships.cache (or substitute to your webserver user)
  • work now?

Ok so I completed the steps you gave above and rebooted.

[[email protected] cache]# ls -l
total 240
-rw-r–r--. 1 nginx nginx 0 Jul 17 12:58 devices_relationships.cache
-rw-r–r--. 1 librenms librenms 242192 Jul 17 09:58 os_defs.cache

Still getting the same error in librenms.log.

[2019-07-17 13:05:48] production.ERROR: file_put_contents(/opt/librenms/cache/devices_relationships.cache): failed to open stream: Permission denied {“userId”:1,“exception”:"[object] (ErrorException(code: 0): fi$
[stacktrace]
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, ‘file_put_conten…’, ‘/opt/librenms/L…’, 173, Array)

Just noticed in the nginx documentation you followed the php group is apache in /etc/php-fpm.d/www.conf https://docs.librenms.org/Installation/Installation-CentOS-7-Nginx/

Not sure i understand why that would be, i would test by changing the group to nginx , restart php-fpm and try again.

Possibly also chgrp nginx /var/lib/php/session/

Permissions is messed up somewhere, find the user/group php is running under and make sure thats applied to the above file.

I just created a new vm and followed the centos apache instructions and have ended up with the same exact issue with the same errors in librenms.log. Tomorrow I will try the ubuntu instructions to see what I get.

1 Like

Hmm ! checked it with SELinux off just incase?, will be interesting if Ubuntu is successful

I had the same issue with my install, after a few days the issue went away, I was able to create groups no problem. I dont know the cause. I did fix the daily.sh , I did not have that in cron. ( reminder , run that command as the Libernms user account. jb

Interesting! I just tried again with the ubuntu and nginx instructions and still have the same result.

Thanks for the SELinux suggestion.

grep os_defs.cache /var/log/audit/audit.log | audit2why

type=AVC msg=audit(1610047568.195:26389): avc: denied { write } for pid=3603 comm=“php” name=“os_defs.cache” dev=“dm-0” ino=1781197 scontext=system_u:system_r:httpd_t:s0 tcontext=system_u:object_r:usr_t:s0 tclass=file permissive=0

    Was caused by:
            Missing type enforcement (TE) allow rule.

            You can use audit2allow to generate a loadable module to allow this access.

Now I just have to figure out how to use audit2allow.