# Nagios
[TOC]
- [**My Nagios**](http://10.21.20.137/nagios/)

## Installation
> OS: **Freebsd 13**
> The **Nagios Core engine** and **Nagios plugin** both need to be install.
### SOP
- [Nagios Core - Installing Nagios on FreeBSD](https://support.nagios.com/kb/article/nagios-core-installing-nagios-core-from-source-96.html#FreeBSD)
> Note: the Nagios Plugins version should be **2.2.1**
- Add user

	htpasswd /usr/local/nagios/etc/htpasswd.users username

### Path of files
- Example of Nagios config file were under `/usr/local/nagios/etc/`

	-rw-rw-r--  1 nagios  nagios  13710 Oct 17 10:24 cgi.cfg
	-rw-rw-r--  1 nagios  nagios  13710 Oct 17 08:51 cgi.cfg.old
	-rw-r--r--  1 root    nagios     95 Oct 20 12:02 htpasswd.users
	-rw-rw-r--  1 nagios  nagios  45847 Oct 17 10:24 nagios.cfg
	-rw-rw-r--  1 nagios  nagios  45847 Oct 17 08:51 nagios.cfg.old
	drwxrwxr-x  2 nagios  nagios    512 Oct 17 10:24 objects
	-rw-rw----  1 nagios  nagios   1312 Oct 17 10:24 resource.cfg
	-rw-rw----  1 nagios  nagios   1312 Oct 17 08:51 resource.cfg.old

- Example of Apache config file were under `/usr/local/etc/apache24/`

## Config File
- There are serveral sample config files you can refer to. All are under **`usr/local/nagios/etc/objects/`**.
- Creat a dir called `demo` for configuration files.
- Add a line to `/usr/local/nagios/etc/objects/nagios.cfg`

        cfg_dir=/usr/local/nagios/etc/objects/obj_demo1

- [Rules for Object Definitions](https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/3/en/objectdefinitions.html)
- There are several kinds of object could be defined
- Host
- Host group
- Service
- Service group
- Contact
- Contact group
- Command
- After creating the config file

	/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
	service nagios restart

### Template
- You can create your own defined objects, or just use the one defined in `template.cfg`.
- Path of sample templates: `/usr/local/nagios/etc/objects/templates.cfg`
- The configurations defined in the template will be applied on any host that is defined to use it.
-
### Define Host
- Define/Write down the hosts' information which would being managed.

### Define Host Group
- Group the hosts you defined in `hosts.cfg`.

### Define Service
- Check services with **non-default port number**
- For example, if the host's **ssh** service via the port 3261, the command in *define service { }* should become:

		check_command    check_ssh!-p 3261

### Define Service Group

### Define Contact
- Admin information

### Define Contact Group

### Define Command

## [Monitoring Linux/Unix Machines](https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/4/en/monitoring-linux.html)
## [Monitoring Routers and Switches](https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/4/en/monitoring-routers.html)
## Reference
### Official
- [Nagios doc](https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/4/en/toc.html)
- [Guide articles list](https://support.nagios.com/kb/category.php?id=172)

- [Tutorialspoint - Nagios](https://www.tutorialspoint.com/nagios/nagios_overview.htm)
### Article
- [Add Hosts to Nagios Server For Monitoring](https://kifarunix.com/add-hosts-to-nagios-server-for-monitoring/)
- [Install and Configure Nagios in FreeBSD12](https://www.osradar.com/install-and-configure-nagios-in-freebsd12/)
- [Install Nagios Core on FreeBSD 13](https://kifarunix.com/install-nagios-core-on-freebsd-13/)