Foreach in own tag fails while in-tag doesn't

[u.avsec]

Hi,
I stumbled into a situation I can't explain to myself:

<?foreach {/ce-pe-port/static/customer-routes}?>
    <ip-route-forwarding-list>
        <prefix>{customer-prefix}</prefix>
        <mask>{customer-prefix-mask}</mask>
        <forwarding-address>{customer-prefix-nh}</forwarding-address>
    </ip-route-forwarding-list>
<?end?>

This fails on packages reload with `Invalid parameters for processing instruction foreach`.

This on the other hand:

<ip-route-forwarding-list foreach="{/ce-pe-port/static/customer-routes}">
    <prefix>{customer-prefix}</prefix>
    <mask>{customer-prefix-mask}</mask>
    <forwarding-address>{customer-prefix-nh}</forwarding-address>
</ip-route-forwarding-list>

Works just fine.

Model in question is `/container/container/list`. Between the two containers there is a choice and case and the list has a 3 part combined key of "customer-prefix*" nodes seen in the example.

I'm really curious what is going on here. NSO version is 5.8.7.

Thanks

[hazad]

What does your yang models look like? I don't get the error when I use the following template:

<config-template xmlns="http://tail-f.com/ns/config/1.0" servicepoint="template-service-servicepoint">
  <test xmlns="http://com/example/templateservice">
  <?foreach {/ce-pe-port/static/customer-routes}?>
    <ip-route-forwarding-list>
      <prefix>{customer-prefix}</prefix>
      <mask>{customer-prefix-mask}</mask>
      <forwarding-address>{customer-prefix-nh}</forwarding-address>
    </ip-route-forwarding-list>
  <?end?>
  </test>
</config-template>

 And the following yang:

container test {
    list ip-route-forwarding-list {
      key "prefix mask forwarding-address";
      leaf prefix {
        type string;
      }
      leaf mask {
        type string;
      }
      leaf forwarding-address {
        type string;
      }
    }

  }

  list template-service {
    key name;
    leaf name {
      type string;
    }

    container ce-pe-port {
      container static {
        list customer-routes {
          key "customer-prefix customer-prefix-mask customer-prefix-nh";
          leaf customer-prefix {
            type string; 
          }
          leaf customer-prefix-mask {
            type string;
          }
          leaf customer-prefix-nh {
            type string;
          }
        }
      }
    }

    uses ncs:service-data;
    ncs:servicepoint template-service-servicepoint;
  }

The template works as expected:

admin@ncs% commit dry-run 
cli {
    local-node {
        data  test {
             +    ip-route-forwarding-list a b c {
             +    }
             +    ip-route-forwarding-list d e f {
             +    }
              }
             +template-service test {
             +    ce-pe-port {
             +        static {
             +            customer-routes a b c;
             +            customer-routes d e f;
             +        }
             +    }
             +}
    }
}

[u.avsec]

Hey,

thanks for trying to look into this.

A string of things happened in an interesting way:

Unfortunately there was a typo in the templates; it is not ce-pe-port but ce-pe-prot in the actual model.

Why stuff above works partially is interesting though. The stand-alone foreach is evaluated by the NSO while the in-tag foreach isn't. The xpath was wrong in both cases but packages reload failed only in first case.

Now, the reason I didn't spot the prot/port typo initially is due to the fact that the NSO actually loops without the need for the foreach in this case. So it went like this:

1. Trying stand-alone foreach -> package reload fails
2. Trying same faulty xpath with in-tag foreach -> package reload succeeds
3. Run test instance -> configuration is actually generated
   1. Foreach actually failed because of faulty xpath
   2. NSO looped through the list data automatically anyway based on the xpath in <prefix></prefix>