Reset to default on deletion of config in CDB

YANG
1

Hi,

I have a query related to default values.
I am using openconfig stp configuration with some annotations on top of it.
default values are defined for config leafs.
when i do “no stp”, configuration is getting deleted and config leafs are set to default values.
But looks like leafs does not exist in CDB. when i tried to save configuration, no data related to stp is saved?
Could you let me know if there is a way to retain the leafs in CDB.

~Karthik

2

Handling default values is a bit tricky topic, but shortly, if you always want default values to be reported, set /confdConfig/defaultHandlingMode to report-all; if you just want then to be saved in your save command, use something like save /my/file stp | details.

See the confd.conf documentation for more details on default handling, also the RFC 6243 may be help you understand how default values work.

3

Hi @mvf ,

Thanks for the reply.
In my use case, when i do “no stp” and commit , i am expecting few config leafs to be retained, but values set to default values in CDB.

4

If you do no stp, there is nothing in CDB under the container stp, not even leafs with default value; not unless you set defaultHandlingMode to report-all, in which case it at least behaves as if these leafs were there if their parents were there too.

5

Hi @mvf ,

When “no stp” is called, in the backend code i see MOP_VALUE_SET is coming and cdb_exists is true.
After that when i try to save config using maapi_save_config, then data is not present. Could you please let me knwo if there any way i can set the value, so that data will be present?

~Karthik

6

You can use the maapi_save_config() MAAPI_CONFIG_WITH_DEFAULTS flag. See the confd_lib_maapi(5) man page for details.

Use the -W option with the confd_load tool to use the MAAPI_CONFIG_WITH_DEFAULTS flag. See the confd_load(1) man page for details.

7

Thanks @cohult
Apart from saving config, is there any way that i can do from backend code to set it to CDB?
I have a upgrade scenario where i am expecting values in CDB.

8

If you have /confdConfig/defaultHandlingMode set to “explicit” or “report-all” in confd.conf, for the leafs that have default values, you can set those leafs to the default value using MAAPI and the values will then be stored in CDB.
Example:

$ pwd
/confd/examples.confd/intro/1-2-3-start-query-model
$ make all start
...
$ confd_load -Fp -p /dhcp
<config xmlns="http://tail-f.com/ns/config/1.0">
</config>
$ confd_load -Fp -W -p /dhcp
<config xmlns="http://tail-f.com/ns/config/1.0">
  <dhcp xmlns="http://tail-f.com/ns/example/dhcpd">
    <default-lease-time>PT600S</default-lease-time>
    <max-lease-time>PT7200S</max-lease-time>
    <log-facility>local7</log-facility>
  </dhcp>
</config>
$ confd_load -Fp -W -p /dhcp > init.xml
$ confd_load -m -l init.xml
$ confd_load -Fp -p /dhcp
<config xmlns="http://tail-f.com/ns/config/1.0">
  <dhcp xmlns="http://tail-f.com/ns/example/dhcpd">
    <default-lease-time>PT600S</default-lease-time>
    <max-lease-time>PT7200S</max-lease-time>
    <log-facility>local7</log-facility>
  </dhcp>
</config>
9

Thanks @cohult
Will check if I can set from backend code using maapi