ITL: Implement various options for the 'snmp' CheckCommand, including mib-list

refs #8498

Signed-off-by: Gunnar Beutner <gunnar@beutner.name>

doc/9-monitoring-remote-systems.md

@@ -634,12 +634,17 @@ have the `snmp-community` custom attribute.
 
       check_command = "snmp"
       vars.snmp_oid = "1.3.6.1.2.1.1.3.0"
+      vars.snmp_miblist = "DISMAN-EVENT-MIB"
 
       assign where host.vars.snmp_community != ""
     }
 
 Additional SNMP plugins are available using the [Manubulon SNMP Plugins](7-icinga-template-library.md#snmp-manubulon-plugin-check-commands).
 
+If no `snmp_miblist` is specified the plugin will default to `ALL`. As the number of available MIB files 
+on the system increases so will the load generated by this plugin if no `MIB` is specified.
+As such, it is recommended to always specify at least one `MIB`.
+
 ### <a id="agent-based-checks-ssh"></a> SSH
 
 Calling a plugin using the SSH protocol to execute a plugin on the remote server fetching

itl/command-plugins.conf

@@ -749,6 +749,13 @@ object CheckCommand "snmp" {
 			set_if = "$snmp_invert_search$"
 			description = "Invert search result and return CRITICAL if found"
 		}
+		"-P" = "$snmp_version$"
+		"-m" = "$snmp_miblist$"
+		"--rate-multiplier" = "$snmp_rate_multiplier$"
+		"--rate" = {
+			set_if = "$snmp_rate$"
+			description = "Enable rate calculation"
+		}
 	}
 
 	vars.snmp_address = {{