Triggers¶

The trigger feature allows the launching of commands in response to an event. This event can be either an alarm reaching a given severity level, the value of a pushed state leaf meeting certain conditions, or periodic.

Trigger on alarm¶

Both system and user alarms can be used in a trigger. When an alarm reaches the configured severity level, the specified commands are applied to the system.

Trigger on system alarm¶

System alarms (capacity alarms, service alarms, link alarms, etc.) are available by default. Their names can be found using show alarm inventory.

In this example, a trigger is configured to execute commands when the fp-conntracks capacity alarm reaches the critical severity level:

vsr running config# / system trigger event conntrack-full on-alarm alarm fp-conntracks severity-level critical
vsr running config#! / system trigger event conntrack-full log true
vsr running config#! / system trigger event conntrack-full commands "
... show alarm list
... "

Here the associated state:

vsr> show state / system trigger
trigger
    enabled true
    event conntrack-full
        enabled true
        log true
        commands "
show alarm list
"
        on-alarm
            alarm fp-conntracks
            severity-level critical
            ..
        ..
    ..

Trigger on user alarm¶

User alarms are custom alarms defined in the alarm configuration. They allow triggering on arbitrary pushed state leaves.

Let’s start by creating a loopback interface:

vsr running config# / vrf main interface loopback lo1 ipv4 address 1.1.1.1/24

Then, create a user alarm that is raised when an ICMP tracker named ICMP-TRACKER goes down:

vsr running config# / tracker icmp ICMP-TRACKER address 1.1.1.1 vrf main
vsr running config#
vsr running config# / system alarm user-alarm icmp-tracker-down description "Alarm raising when the ICMP tracker ICMP-TRACKER goes down."
vsr running config#! / system alarm user-alarm icmp-tracker-down resource "/tracker/icmp[name='ICMP-TRACKER']/state"
vsr running config#! / system alarm user-alarm icmp-tracker-down severity-level-trigger critical text "Tracker ICMP-TRACKER {value}, alarm {name}"
vsr running config# / system alarm user-alarm icmp-tracker-down severity-level-trigger critical equal down
vsr running config# / system alarm user-alarm icmp-tracker-down severity-level-trigger cleared text "Tracker ICMP-TRACKER {value}"

In this scenario, we have an ICMP tracker named ICMP-TRACKER which is monitored for its operational status. When this ICMP tracker goes down, it raises an alarm. Now, we will add a trigger. When the alarm reaches the critical state, it will be activated. It will configure a loopback interface and display its state:

vsr running config# / system trigger event trigger-icmp-tracker-down on-alarm alarm icmp-tracker-down severity-level critical
vsr running config#! / system trigger event trigger-icmp-tracker-down log true
vsr running config#! / system trigger event trigger-icmp-tracker-down commands "
... edit running
... / vrf main interface loopback lo2 ipv4 address 2.2.2.2/32
... commit
... show state / vrf main interface loopback lo2 ipv4 address"

Here the associated state:

vsr> show state / system trigger
trigger
    enabled true
    event trigger-icmp-tracker-down
        enabled true
        log true
        commands "
edit running
/ vrf main interface loopback lo2 ipv4 address 2.2.2.2/32
commit
show state / vrf main interface loopback lo2 ipv4 address"
        on-alarm
            alarm icmp-tracker-down
            severity-level critical
            ..
        ..
    ..

Then, disable the interface to trigger the alarm and the event:

vsr running config# / vrf main interface loopback lo1 enabled false

Finally, let’s go check the logs of our event:

vsr> show log service trigger
Mar 23 12:28:55 vsr systemd[1]: Started trigger@trigger-icmp-tracker-down.service - Trigger Command Logger Service for trigger/icmp/tracker/down.
Mar 23 12:28:56 vsr trigger@trigger/icmp/tracker/down[2845]: Configuration committed.
Mar 23 12:28:56 vsr trigger@trigger/icmp/tracker/down[2845]: No data
Mar 23 12:28:56 vsr systemd[1]: trigger@trigger-icmp-tracker-down.service: Deactivated successfully.

The same configuration can be made using this NETCONF XML configuration:

vsr> show config xml absolute / system trigger event trigger-icmp-tracker-down
<config xmlns="urn:6wind:vrouter">
  <system xmlns="urn:6wind:vrouter/system">
    <trigger xmlns="urn:6wind:vrouter/trigger">
      <event>
        <name>trigger-icmp-tracker-down</name>
        <enabled>true</enabled>
        <log>true</log>
        <commands>
edit running
/ vrf main interface loopback lo2 ipv4 address 2.2.2.2/32
commit
show state / vrf main interface loopback lo2 ipv4 address</commands>
        <on-alarm>
          <alarm>icmp-tracker-down</alarm>
          <severity-level>critical</severity-level>
        </on-alarm>
      </event>
    </trigger>
  </system>
</config>

Trigger periodically¶

It is possible to configure a trigger in a manner similar to a crontab.

Note

The cron time format uses the standard five-field format:

┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of the month (1 - 31)
│ │ │ ┌───────────── month (1 - 12 or Jan, Feb, Mar, Apr, ...)
│ │ │ │ ┌───────────── day of the week (0 - 6 or Sun, Mon, Tue, Wed, ...)
│ │ │ │ │
* * * * *

Trigger on resource¶

A pushed leaf can be used in a trigger. The resource must correspond to a pushed leaf; otherwise, it will never be taken into account.

See also

The command reference for the full list of options.

In this example, we’re going to replicate the setup used for the alarm, but this time we will directly implement a trigger without an associated alarm. This approach will help to understand the similarities in configurations:

vsr running config# / system trigger event trigger-icmp-tracker-down on-resource resource "/tracker/icmp[name='ICMP-TRACKER']/state" equal down
vsr running config#! / system trigger event trigger-icmp-tracker-down log true
vsr running config#! / system trigger event trigger-icmp-tracker-down commands "
... edit running
... / vrf main interface physical eth1 mtu 1500
... commit
... "

Here the associated state:

vsr> show state / system trigger
trigger
    enabled true
    event trigger-icmp-tracker-down
        enabled true
        log true
        commands "
edit running
/ vrf main interface physical eth1 mtu 1500
commit
"
        on-resource
            resource "/tracker/icmp[name='ICMP-TRACKER']/state"
            equal down
            ..
        ..
    ..

The same configuration can be made using this NETCONF XML configuration:

vsr> show config xml absolute / system trigger event trigger-icmp-tracker-down
<config xmlns="urn:6wind:vrouter">
  <system xmlns="urn:6wind:vrouter/system">
    <trigger xmlns="urn:6wind:vrouter/trigger">
      <event>
        <name>trigger-icmp-tracker-down</name>
        <enabled>true</enabled>
        <log>true</log>
        <commands>
edit running
/ vrf main interface physical eth1 mtu 1500
commit
</commands>
        <on-resource>
          <resource>/tracker/icmp[name='ICMP-TRACKER']/state</resource>
          <equal>down</equal>
        </on-resource>
      </event>
    </trigger>
  </system>
</config>