librenms

A Puppet module for managing LibreNMS

Usage

The Puppet manifest used by Vagrant (vagrant/librenms.pp) shows how to

• Setup LibreNMS (install, configuration, permissions, ACLs, users, etc.)
• Use puppetlabs-mysql to configure database, user and grants
• Setup snmpd and create and SNMPv3 user
• Add the LibreNMS node to LibreNMS

The manifest used by Vagrant uses two optional features of this module that

• Install the required php packages
• Configure Apache to serve LibreNMS on port 80 (http)

Hints for production

To import a node into LibreNMS using exported resources:

class { '::snmpd':
  allow_address_ipv4 => '10.0.0.0',
  allow_netmask_ipv4 => '8',
  users              => { 'monitor' => { 'pass' => 'my-password' } },
}

class { '::librenms::device':
  proto => 'v3',
  user  => 'monitor',
  pass  => 'my_password',
}

To use SNMPv2 instead:

class { '::librenms::device':
  proto      => 'v2',
  community  => 'public',
}

Create and remove devices using LibreNMS v0 API:

librenms_device { 'snmpv3.example.org':
  ensure     => 'present',
  url        => 'https://librenms.example.org/api/v0',
  auth_token => '0123456789abcde0123456789abcded0',
  snmpver    => 'v3',
  authlevel  => 'noAuthNoPriv',
  authname   => 'snmpuser',
  authpass   => 'secret',
  authalgo   => 'sha',
  cryptopass => 'secret',
  cryptoalgo => 'aes',
}

librenms_device { 'snmpv2.example.org':
  ensure     => 'present',
  url        => 'https://librenms.example.org/api/v0',
  auth_token => '0123456789abcde0123456789abcded0',
  snmpver    => 'v2c',
  community  => 'public',
}

# Ensure that a decommissioned node is not present in LibreNMS
librenms_device { 'decommissioned.example.org':
  ensure => 'absent',
}

The provider uses the "force_add" parameter to ensure that nodes that are (temporarily) inaccessible (e.g. being provisioned) are added correctly.

You can also manage services using the LibreNMS v0 API:

librenms_service { 'http-on-librenms':
  ensure     => 'present',
  url        => 'http://librenms.example.org/api/v0',
  auth_token => '0123456789abcde0123456789abcded0',
  hostname   => 'librenms.example.org',
  type       => 'http',
  ip         => 'librenms.example.org',
  param      => 'C 50 --sni -S',
}

There are couple of caveats regarding service management:

• The "desc" parameter, which defaults to the resource title, is used as an identifier at the LibreNMS. This is because it is the only property which is purely informational. You can use this to import existing resources to Puppet. If multiple services matching the same "desc" on the same device are found then Puppet will bail out and ask you to resolve the situation.
• No verification is done on any of the parameters at Puppet or LibreNMS end except for basic data type validation. For example you can change "type" from "http" (valid) to "https" (invalid) without any errors or warnings.

Testing with Vagrant

If you have Vagrant and virtualbox installed then setting up LibreNMS test instance from scratch should be as easy as:

$ vagrant up

LibreNMS UI can be reached via https://192.168.152.10. Username is "admin" and password is "vagrant". The instance adds itself to LibreNMS, so you should see one device, "librenms.vagrant.example.lan" under devices.

If you want to use snmpwalk note that the username is "librenms" and password is "vagrant123".

Testing AWS AMI images created with Packer

We use vagrant-aws Vagrant plugin to ease testing of packer-generated LibreNMS AMI images. First you need to setup vagrant-aws as per documentation:

$ vagrant plugin install vagrant-aws
$ vagrant box add dummy https://github.com/mitchellh/vagrant-aws/raw/master/dummy.box

Then make sure that the following standard AWS environment variables are set:

• AWS_SECRET_ACCESS_KEY
• AWS_ACCESS_KEY_ID

Optionally you can also set

• AWS_DEFAULT_REGION: define which region Vagrant creates the instance to

There are a few non-standard environment variables you need to set as well:

• AWS_AMI: the AMI ID that has puppetmaster-installer preconfigured
• AWS_KEY_PAIR_NAME: the name of the SSH keypair at the AWS end
• SSH_PRIVATE_KEY_PATH: path to the SSH private key matching the SSH keypair name, above

Once all these are set, you can use create, connect to and destroy the AWS instances as needed:

$ AWS_AMI=<ami-id> vagrant up librenms-bionic-aws
$ vagrant ssh librenms-bionic-aws
$ vagrant destroy librenms-bionic-aws