Defining a new NETCONF RPC

NETCONF
1

Trying to get a new RPC running. I add this yang:
module testrpc {
namespace “http://example.com/ns/yang/testrpc”;
prefix testrpc;

  import ietf-inet-types {
    prefix inet;
  }

  import tailf-common {
    prefix tailf;
  }

  organization "Test";

  contact "Test@example.com";

  rpc testrpc {
    tailf:exec "/bin/uname";
    output {
      leaf res {
        type string;
      }
    }
  }
}

I compile with source confd/confdrc; confdc -c testrpc.yang and copy the fxs into the load path of my confd instance.

I add <capability>http://example.com/ns/yang/testrpc</capability> to /confdConfig/netconf/capabilities` and restart confd.

Now I issue netconf-console --proto=tcp --port=2022 --host=192.168.1.12 -u myuser -p mypassword testrpc.xml where testrpc.xml is:

<?xml version="1.0" encoding="UTF-8"?>
<hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <capabilities>
    <capability>urn:ietf:params:netconf:base:1.0</capability>
  </capabilities>
</hello>
]]>]]>
<?xml version="1.0" encoding="UTF-8"?>
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="1">
  <testrpc xmlns="http://example.com/ns/yang/testrpc"/>
</rpc>
]]>]]>
<?xml version="1.0" encoding="UTF-8"?>
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="2">
  <close-session/>
</rpc>
]]>]]>

My response in netconf-console is:

<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="1">
  <rpc-error>
    <error-type>application</error-type>
    <error-tag>operation-failed</error-tag>
    <error-severity>error</error-severity>
    <error-path xmlns:testrpc="http://example.com/ns/yang/testrpc"     xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0">
    /nc:rpc/testrpc:testrpc
  </error-path>
    <error-message xml:lang="en">application protocol error</error-message>
    <error-info>
      <bad-element>testrpc</bad-element>
    </error-info>
  </rpc-error>
</rpc-reply>

The logs from the confd instance show:
confd Bad result from external command "/bin/uname": "Linux\n"

Can someone help me out? Is there a requirement on how the output should be formatted to be accepted as an RPC reply, or am I missing something else? The example was chosen to have a short succinct reply string to test creating RPCs that run serverside commands.

TIA&BR /Erik

2

Yes, see the section “11.3. Action as an Executable” in the UG. The output should be “tag-value” pairs just like the input. If you change “/bin/uname” to the path of a script that does

echo res `/bin/uname`

(where ‘res’ is of course the name you have defined for the output parameter) it should work.

1 Like
3

That was exactly it. I was stuck in 15.5 where I didn’t get that detail. Thank you.