Graylog integration

We have simple integration for Graylog, you will be able to view any logs from within LibreNMS that have been parsed by the syslog input from within Graylog itself. This includes logs from devices which aren't in LibreNMS still, you can also see logs for a specific device under the logs section for the device.

Currently, LibreNMS does not associate shortnames from Graylog with full FQDNS. If you have your devices in LibreNMS using full FQDNs, such as hostname.example.com, be aware that rsyslogd, by default, sends the shortname only. To fix this, add

$PreserveFQDN on

to your rsyslog config to send the full FQDN so device logs will be associated correctly in LibreNMS. Also see near the bottom of this document for tips on how to enable/suppress the domain part of hostnames in syslog-messages for some platforms.

Graylog itself isn't included within LibreNMS, you will need to install this separately either on the same infrastructure as LibreNMS or as a totally standalone appliance.

Config is simple, here's an example based on Graylog 2.4:

lnms config:set graylog.server 'http://127.0.0.1'
lnms config:set graylog.port 9000
lnms config:set graylog.username admin
lnms config:set graylog.password 'admin'
lnms config:set graylog.version 2.4

Timezone

Graylog messages are stored using GMT timezone. You can display graylog messages in LibreNMS webui using your desired timezone by setting the following option using lnms config:set:

lnms config:set graylog.timezone 'Europe/Bucharest'

Timezone must be PHP supported timezones, available at: https://php.net/manual/en/timezones.php

Graylog Version

If you are running a version earlier than Graylog then please set

lnms config:set graylog.version 2.1

to the version number of your Graylog install. Earlier versions than 2.1 use the default port 12900

URI

If you have altered the default uri for your Graylog setup then you can override the default of /api/ using

lnms config:set graylog.base_uri '/somepath/'

User Credentials

If you don't want to use an admin account for connection to Graylog Log into http:///api/api-browser/global/index.html using graylog admin credentials Browse to: Roles: User roles Click on: Create a new role In JSON body paste this:

{
    "name": "LibreNMS-Read",
    "description": "Extended reading permissions for LibreNMS",
    "permissions" : [
        "searches:relative",
        "streams:read"
    ]
}

Otherwise you must give the user "admin" permissions from within Graylog, "read" permissions alone are not sufficient.

TLS Certificate

If you have enabled TLS for the Graylog API and you are using a self-signed certificate, please make sure that the certificate is trusted by your LibreNMS host, otherwise the connection will fail. Additionally, the certificate's Common Name (CN) has to match the FQDN or IP address specified in

lnms config:set graylog.server example.com

Match Any Address

If you want to match the source address of the log entries against any IP address of a device instead of only against the primary address and the host name to assign the log entries to a device, you can activate this function using

lnms config:set graylog.match-any-address true

Recent Devices

There are 2 configuration parameters to influence the behaviour of the "Recent Graylog" table on the overview page of the devices.

lnms config:set graylog.device-page.rowCount 10

Sets the maximum number of rows to be displayed (default: 10)

lnms config:set graylog.device-page.loglevel 7

You can set which loglevels that should be displayed on the overview page. (default: 7, min: 0, max: 7)

lnms config:set graylog.device-page.loglevel 4

Shows only entries with a log level less than or equal to 4 (Emergency, Alert, Critical, Error, Warning).

You can set a default Log Level Filter with

lnms config:set graylog.loglevel 7

Domain and hostname handling

Suppressing/enabling the domain part of a hostname for specific platforms

You should see if what you get in syslog/Graylog matches up with your configured hosts first. If you need to modify the syslog messages from specific platforms, this may be of assistance:

IOS (Cisco)

router(config)# logging origin-id hostname

or

router(config)# logging origin-id string

JunOS (Juniper Networks)

set system syslog host yourlogserver.corp log-prefix YOUR_PREFERRED_STRING

PanOS (Palo Alto Networks)

set deviceconfig setting management hostname-type-in-syslog hostname

or

set deviceconfig setting management hostname-type-in-syslog FQDN