Kicker Trigger Expression

[neetimit]

Hi All,

I am writing a template for data kicker, I have used a trigger expression like this:

<trigger-expr>/devices/device[name='{$device}']/config/ios:interface/{$interface-type}[name='{$interface-id}']/shutdown='false'</trigger-expr>

But it seems this is always evaluating to False, even when shutdown is true on the interface for eg, when I change the shutdown on CLI I get this message in debug kicker output:

device-IOS3-Ethernet-id-0/81-IOS6 at /ncs:devices/ncs:device[ncs:name='IOS3']/ncs:config/ios:interface/ios:Ethernet[ios:name='0/81']/ios:shutdown changed; not invoking 'add-ce-re-deploy-action' trigger-expr false -> false

Can someone please suggest what is wrong with the expression I am using? 

Thanks,

Neetika

[lmanor]

In the ios NED the interface shutdown leaf is not a boolean, it is specified as type empty:

    // interface * / shutdown

    leaf shutdown {

      // Note: default to "no shutdown" in order to be able to bring if up.

      tailf:info "Shutdown the selected interface";

      tailf:cli-show-no;

      tailf:cli-full-command;

      type empty;

    }

You'll need to check for existence of the the shutdown leaf - value comparison with a leaf that doesn’t exist (i.e. “an empty node-set”) evaluates to false.

So instead of checking for the shutdown leaf = false you need to check the path expression = false.

Haven't tested the syntax, but perhaps something like this:

<trigger-expr>"/devices/device[name='{$device}']/config/ios:interface/{$interface-type}[name='{$interface-id}']/shutdown"='false'</trigger-expr>

[neetimit]

Hi,

Thank you for the inputs, I agree since shutdown is type empty, I need to check the path expression.

I tried this kicker now:

admin@ncs# show running-config kickers 

kickers data-kicker device-IOS3-Ethernet-id-2/2-IOS6

 monitor      /devices/device[name='IOS3']/config/ios:interface/Ethernet[name='2/2']/shutdown

 trigger-expr "\"/devices/device[name='IOS3']/config/ios:interface/Ethernet[name='2/2']/shutdown\"='false'"

 trigger-type enter

 kick-node    /services/cfs-services:cfs-services[name='fia3']/add-ce-re-deploy

 action-name  add-ce-re-deploy-action

!

However, it is still giving me the same results when I add or remove shutdown on the interface:

admin@ncs(config-if)# commit dry-run | debug kicker

 2019-12-18T09:56:17.961 kicker: device-IOS3-Ethernet-id-2/2-IOS6 at /ncs:devices/ncs:device[ncs:name='IOS3']/ncs:config/ios:interface/ios:Ethernet[ios:name='2/2']/ios:shutdown changed; not invoking 'add-ce-re-deploy-action' trigger-expr false -> false

cli {

    local-node {

        data  devices {

                  device IOS3 {

                      config {

                          ios:interface {

                              Ethernet 2/2 {

             -                    shutdown;

                              }

                          }

                      }

                  }

              }

    }

}

Any clue what might be wrong now?

Thank you

[lmanor · Accepted solution]

Hello, I took a few minutes to look into this...

One key for understanding the config of the kickers was to check out the commentary in the kicker yang modeling in file <nso-inst>/src/ncs/yang/tailf-kicker.yang

The below kicker will fire (and call the action) only when the interface goes from shutdown (shutdown leaf exits) to 'no-shutdown' (shutdown field does not exist) - note: the config trigger-type = enter (not default enter-and-leave which would trigger change both ways t->f and f->t):

admin@ncs% show kickers

data-kicker test-kicker {

    monitor      /ncs:devices/ncs:device[ncs:name='ios-0']/ncs:config/ios:interface/ios:FastEthernet[ios:name='1/0'];

    trigger-expr not(./shutdown);

    trigger-type enter;

    kick-node    hostname:action;

    action-name  change-hostname;

}

[ok][2019-12-18 16:03:02]

[edit]

admin@ncs% show devices device ios-0 config ios:interface FastEthernet 1/0

ip {

    no-address {

        address false;

    }

}

[ok][2019-12-18 16:03:05]

[edit]

admin@ncs% set devices device ios-0 config ios:interface FastEthernet 1/0 shutdown

[ok][2019-12-18 16:03:13]

[edit]

admin@ncs% commit | debug kicker

2019-12-18T16:03:19.611 kicker: test-kicker at /ncs:devices/ncs:device[ncs:name='ios-0']/ncs:config/ios:interface/ios:FastEthernet[ios:name='1/0'] changed; not invoking 'change-hostname' trigger-expr true -> false

Commit complete.

[ok][2019-12-18 16:03:19]

[edit]

admin@ncs% show devices device ios-0 config ios:interface FastEthernet 1/0

ip {

    no-address {

        address false;

    }

}

shutdown;

[ok][2019-12-18 16:03:40]

[edit]

admin@ncs% delete devices device ios-0 config ios:interface FastEthernet 1/0 shutdown

[ok][2019-12-18 16:03:50]

[edit]

admin@ncs% commit | debug kicker

2019-12-18T16:03:55.375 kicker: test-kicker at /ncs:devices/ncs:device[ncs:name='ios-0']/ncs:config/ios:interface/ios:FastEthernet[ios:name='1/0'] changed; invoking 'change-hostname' trigger-expr false -> true

Commit complete.

[neetimit]

Thank you so much, the solution worked perfectly.

[neetimit]

One more query regarding kickers, I am trying to send few input params to the action method like I have the following template for kicker,

<config xmlns="http://tail-f.com/ns/config/1.0">

  <kickers xmlns="http://tail-f.com/ns/kicker">

    <data-kicker>

      <id>device-{$device}-{$interface-type}-id-{$interface-id}-{$ce-device}</id>

     <trigger-expr>not(./shutdown)</trigger-expr>

      <trigger-type>enter</trigger-type>

      <monitor>/devices/device[name='{$device}']/config/ios:interface/{$interface-type}[name='{$interface-id}']</monitor>   

      <kick-node>/services/cfs-services[name='{$name}']/add-ce-re-deploy</kick-node>

      <action-name>add-ce-re-deploy-action</action-name>

    </data-kicker>

  </kickers>

</config>

I am able to get the "name" of cfs-services (in python code by using kp) but other than that if I have to set few other params, what is the easy way to do it?  I am guessing there should be a way to set few params which kicker action can read later when it is invoked.

Any inputs appreciated.