Extra-Opts
Starting with the 1.4.12 release, Nagios C plugins support reading configuration options from a configuration file. This needs to be enabled at compile-time for now (--enable-extra-opts) and will be enabled by default starting with the Nagios Plugins 1.5 release. Perl plugins using Nagios::Plugin have this support since version 0.16.
You can easily know if a plugin support extra-opts by checking the --help output for the "--extra-opts" option. Once compiled in, the --extra-opts plugin option allows reading extra options from a config file. The syntax for the command is:
--extra-opts=[section][@file]
Some examples:
Read special_opts section of default config file:
./check_stuff --extra-opts=special_opts
Read special_opts section of /etc/myconfig.ini
./check_stuff --extra-opts=special_opts@/etc/myconfig.ini
Read check_stuff section of /etc/myconfig.ini
./check_stuff --extra-opts=@/etc/myconfig.ini
Read check_stuff section of default config file and use additional arguments along with the other specified arguments (extra-opts arguments are always processed first no matter where --extra-opts appears on the command line).
./check_stuff --extra-opts -jk --some-other-opt
The default nagios plugins file is used if no explicit filename is given. The current standard locations checked are:
/etc/nagios/plugins.ini
/usr/local/nagios/etc/plugins.ini
/usr/local/etc/nagios/plugins.ini
/etc/opt/nagios/plugins.ini
/etc/nagios-plugins.ini
/usr/local/etc/nagios-plugins.ini
/etc/opt/nagios-plugins.ini
To use a custom location, set a NAGIOS_CONFIG_PATH environment variable to the set of directories that should be checked (this is a colon-separated list just like PATH). The first plugins.ini or nagios-plugins.ini file found in these directories will be used.
To specify an option without parameter, you can use a key without value, but the equal sign must remain, for example:
allow-regex=
Also note that repeated keys are allowed within sections just like you can repeat arguments on the command line.
The basic theory is that options specified in the configuration files are substituted at the beginning of the command line.
The initial use case for this functionality is for hiding passwords, so you do not have to define sensitive credentials in the Nagios configuration and these options won't appear in the command line.