ansible-nagios

Ansible Playbook for setting up the Nagios monitoring system and clients on CentOS/RHEL.

What does it do?

• Automated deployment of Nagios on CentOS or RHEL
  • Generates service checks, and monitored hosts from Ansible inventory
  • Generates comprehensive checks for the Nagios server
  • Generates comprehensive checks for all hosts/services via NRPE
  • Generates most of the other configs based on jinja2 templates
  • Wraps Nagios in SSL via Apache
  • Sets up proper firewall rules (firewalld or iptables-services)
  • This is also available via Ansible Galaxy

Requirements

• RHEL7 or CentOS7+ for Nagios server.

Notes

• Sets the nagiosadmin password to changeme, you'll want to change this.
• Creates a read-only user, set nagios_create_guest_user: false to disable this in install/group_vars/all.yml
• Implementation is very simple, with the following resource/service checks generated:
  • generic out-of-band interfaces (ping, ssh, http)
  • generic Linux servers (ping, ssh, load, users, procs, uptime, disk space)
  • ELK servers (same as servers plus elasticsearch and Kibana)
  • elasticsearch (same as servers plus TCP/9200 for elasticsearch)
  • webservers (http, ping, ssh, load, users, procs, uptime, disk space)
  • network switches (ping, ssh)
  • Dell iDRAC server checks via @dangmocrang check_idrac
    • You can select which checks you want in install/group_vars/all.yml
      • CPU, DISK, VDISK, PS, POWER, TEMP, MEM, FAN
• contacts.cfg notification settings are in install/group_vars/all.yml and templated for easy modification.
• Adding new hosts to inventory file will just regenerate the Nagios configs

Nagios Server Instructions

• Clone repo and setup your Ansible inventory (hosts) file

git clone https://github.com/sadsfae/ansible-nagios
cd ansible-nagios
sed -i 's/host-01/yournagioshost/' hosts

• Add any hosts for checks in the hosts inventory
• Note that you need to add ansible_host entries only for IP addresses for idrac, switches, out-of-band interfaces and anything that typically doesn't support Python and Ansible fact discovery.
• Anything not an idrac, switch or oobserver should use the FQDN (or an /etc/hosts entry) for the inventory hostname or you may see this error:
  • AnsibleUndefinedVariable: 'dict object' has no attribute 'ansible_default_ipv4'}

[webservers]
webserver01

[switches]
switch01 ansible_host=192.168.0.100
switch02 ansible_host=192.168.0.102

[oobservers]
webserver01-ilo ansible_host=192.168.0.105

[servers]
server01

[idrac]
database01-idrac ansible_host=192.168.0.106

• Run the playbook

ansible-playbook -i hosts install/nagios.yml

• Navigate to the server at https://yourhost/nagios
• Default login is nagiosadmin / changeme unless you changed it in install/group_vars/all.yml

Known Issues

SELinux doesn't always play well with Nagios, or the policies may be out of date as shipped with CentOS/RHEL.

avc:  denied  { create } for  pid=8800 comm="nagios" name="nagios.qh

• If you see this (or nagios doesn't start) you'll need to create an SELinux policy module.

# cat /var/log/audit/audit.log | audit2allow -M mynagios
# semodule -i mynagios.pp

Now restart Nagios and Apache and you should be good to go.

systemctl restart nagios
systemctl restart httpd

Demonstration

• You can view a video of the Ansible deployment here:

iDRAC Server Health Details

• The iDRAC health checks are all optional, you can pick which ones you want to monitor.

• The iDRAC health check will provide exhaustive health information and alert upon it.

Files

.
├── hosts
└── install
    ├── group_vars
    │   └── all.yml
    ├── nagios.yml
    └── roles
        ├── nagios
        │   ├── files
        │   │   ├── idrac_2.2rc4
        │   │   ├── idrac-smiv2.mib
        │   │   ├── localhost.cfg
        │   │   ├── nagios.cfg
        │   │   ├── nagios.conf
        │   │   └── services.cfg
        │   ├── tasks
        │   │   └── main.yml
        │   └── templates
        │       ├── cgi.cfg.j2
        │       ├── commands.cfg.j2
        │       ├── contacts.cfg.j2
        │       ├── elasticsearch.cfg.j2
        │       ├── elkservers.cfg.j2
        │       ├── idrac.cfg.j2
        │       ├── oobservers.cfg.j2
        │       ├── servers.cfg.j2
        │       ├── switches.cfg.j2
        │       └── webservers.cfg.j2
        └── nagios-client
            ├── tasks
            │   └── main.yml
            └── templates
                └── nrpe.cfg.j2

10 directories, 22 files