Create an element in CDB

I have few parameters that have default values in my implementation. I am trying to add those parameters with respective values using maapi API.

cos-classifier is a leaf with two enum values in the yang file

However, it does not work for me… maapi_set_elem2() is returning an error all the time…
is there something that I am missing here?
I tried using “pcp” instead of “1” and even “enum<1>” as third argument to maapi_set_elem2().

maapi_set_namespace(msock, maapi_thandle, link__ns);

syslog(LOG_INFO, "setting cos-classifier to be pcp");
if (maapi_set_elem2(msock, maapi_thandle, "1", "/link/cos-classifier") != CONFD_OK) {
    syslog(LOG_ERR, "cos-classifier init to pcp failed");

maapi_apply_trans(msock, maapi_thandle, 0);

if (maapi_finish_trans(msock, maapi_thandle) != CONFD_OK) {
    syslog(LOG_ERR, "%s: failed to finish transaction", __FUNCTION__);
syslog(LOG_INFO, "%s: Changes applied to CDB successfully", __FUNCTION__);


Since you didn’t provide the YANG model for your project, I will use the intro/1-2-3 example to illustrate how maapi_set_elem2( ) works with enum values.

Following is a snippet of dhcpd.yang for the example:

  typedef loglevel {
    type enumeration {
        enum kern;
        enum mail;
        enum local7;

  container dhcp {
    leaf logFacility {
      type loglevel;
      default local7;

You should be using the names of the enum as defined in the YANG when working with the maapi_set_elem2( ) API call. I will demonstrate using the confd_cmd tool which is a wrapper of the ConfD library functions in which the man-page for it can be found in the ConfD User Guide. The mset command translates to maapi_set_elem2( ).

$ confd_cmd -d -c 'mget /dhcp/logFacility'
mget "/dhcp/logFacility"
$ confd_cmd -d -c 'mset /dhcp/logFacility kern'
mset "/dhcp/logFacility" "kern"
$ confd_cmd -d -c 'mget /dhcp/logFacility'
mget "/dhcp/logFacility"

Here is my yang definition.
typedef cndlp-classifier-mode {
type enumeration {
enum vid {
tailf:info “Classification based on vlan tag”;
enum pcp {
tailf:info “Classification based on pcp bits”;
tailf:info “classifier mode [vid|pcp]”;

 leaf cos-classifier {
      when "../mode = 'differentiated'";
      type cndlp-types:cndlp-classifier-mode;
      tailf:info "Mode of traffic treatment based on vlan or pcp";

I tried three different ways: all of them returning an error…
if (maapi_set_elem2(msock, maapi_thandle, “1”, “/link/cos-classifier”) != CONFD_OK) {
if (maapi_set_elem2(msock, maapi_thandle, “pcp”, “/link/cos-classifier”) != CONFD_OK) {
if (maapi_set_elem2(msock, maapi_thandle, “enum<1>”, “/link/cos-classifier”) != CONFD_OK) {

I have tried your YANG model without the when statement and everything works as expected.

Is your mode configured correctly? What error message did you get? Try it again by commenting out the when statement.

Thanks @waitai
Thats a great catch; didnot occur to me!