Add label option to snmp ckecks

Add label option to snmpv3 and snmp snmp-interface commands. Based on attached files to ticket #7545.

fixes #7545

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

doc/7-configuring-icinga-2.md

@@ -2309,6 +2309,7 @@ snmpv3_priv_key   | **Required.** The encryption key.
 snmpv3_oid        | **Required.** The SNMP OID.
 snmpv3_warn       | **Optional.** The warning threshold.
 snmpv3_crit       | **Optional.** The critical threshold.
+snmpv3_label      | **Optional.** Prefix label for output value.
 
 #### <a id="plugin-check-command-snmp-uptime"></a> snmp-uptime
 
@@ -2576,6 +2577,7 @@ snmp_warn                   | **Optional.** The warning threshold.
 snmp_crit                   | **Optional.** The critical threshold.
 snmp_interface              | **Optional.** Network interface name. Default to regex "eth0".
 snmp_interface_perf         | **Optional.** Check the input/ouput bandwidth of the interface. Defaults to "true".
+snmp_interface_label        | **Optional.** Add label before speed in output: in=, out=, errors-out=, etc...
 snmp_interface_bits_bytes   | **Optional.** Output performance data in bits/s or Bytes/s. **Depends** on snmp_interface_kbits set to "true". Defaults to "true".
 snmp_interface_percent      | **Optional.** Output performance data in % of max speed. Defaults to "false".
 snmp_interface_kbits        | **Optional.** Make the warning and critical levels in KBits/s. Defaults to "true".

itl/command-plugins-manubulon.conf

@@ -153,6 +153,7 @@ object CheckCommand "snmp-interface" {
 		"-k" = {
 			set_if = "$snmp_interface_perf$"
 		}
+		"--label" = "$snmp_interface_label$"
 		"-Y" = {
 			set_if = "$snmp_interface_bits_bytes$"
 		}

itl/command-plugins.conf

@@ -588,6 +588,7 @@ object CheckCommand "snmpv3" {
 		"-o" = "$snmpv3_oid$"
 		"-c" = "$snmpv3_crit$"
 		"-w" = "$snmpv3_warn$"
+		"-l" = "$snmpv3_label$"
 	}
 
 	vars.snmpv3_address = "$address$"