How to send RPC messages while netconf server is running?

[anoikob]

Hello. I know that the general idea of netconf is to edit the candidate datastore, and then commit the changes to the running datastore. Is there a way to edit only parts of a datastore without accessing the xml file with sysrepocfg? Say I have this candidate datastore

<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"> <interface> <name>eth0</name> <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type> <enabled>true</enabled> <bridge-port xmlns="urn:ieee:std:802.1Q:yang:ieee802-dot1q-bridge"> <port-type xmlns:dot1q="urn:ieee:std:802.1Q:yang:ieee802-dot1q-bridge">dot1q:provider-network-port</port-type> <cbsa xmlns="urn:ieee:std:802.1Q:yang:ieee802-dot1q-cbsa-bridge"> <cbsa-parameter-table> <traffic-class>0</traffic-class> <admin-idle-slope>1000000</admin-idle-slope> </cbsa-parameter-table> </cbsa> </bridge-port> </interface> </interfaces> <keystore xmlns="urn:ietf:params:xml:ns:yang:ietf-keystore"> <asymmetric-keys> <asymmetric-key> <name>genkey</name> <algorithm>rsa2048</algorithm> <public-key>MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsKs9JB7+4mXV0qmEmmE8r3bU2sifGKrtwYai1kLqbFEVp5EicfF1LFLcEjr04hIjTwi/FDkGmli9zizsiqpXQj/bmX0k3f+Oztu7Ozk5tdGyrC095k5Ntfm8y7JT4Fp7caxU2Sc6RtByI1H9FjWGcCBNx2PG2QGHXQ4t/JEttKEawY3VmwtF1MZsglQ4fKLnHoDi4R49dsPWuYgUh> <private-key>MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKYwggSiAgEAAoIBAQCwqz0kHv7iZdXSqYSaYTyvdtTayJ8Yqu3BhqLWQupsURWnkSJx8XUsUtwSOvTiEiNPCL8UOQaaWL3OLOyKqldCP9uZfSTd/47O27s7OTm10bKsLT3mTk21+bzLslPgWntxrFTZJzpG0HIjUf0WNYZwIE3HY8bZAYddDi38kS20oRrBjdWbC0XUxmyCVDh8oucegOLhHj12> </asymmetric-key> </asymmetric-keys> </keystore> <nacm xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-acm"> <enable-nacm>false</enable-nacm> <read-default>permit</read-default> <write-default>permit</write-default> <exec-default>permit</exec-default> <groups> <group> <name>netconf-group</name> <user-name>netconf</user-name> </group> </groups> <rule-list> <name>permit-netconf</name> <group>netconf-group</group> <rule> <name>permit-ietf-interfaces</name> <module-name>ietf-interfaces</module-name> <access-operations>*</access-operations> <action>permit</action> </rule> </rule-list> </nacm> <netconf-server xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server"> <listen> <endpoint> <name>default-ssh</name> <ssh> <tcp-server-parameters> <local-address>0.0.0.0</local-address> <keepalives> <idle-time>3</idle-time> <max-probes>10</max-probes> <probe-interval>5</probe-interval> </keepalives> </tcp-server-parameters> <ssh-server-parameters> <server-identity> <host-key> <name>default-key</name> <public-key> <keystore-reference>genkey</keystore-reference> </public-key> </host-key> </server-identity> <client-authentication> <supported-authentication-methods> <publickey/> <passsword/> </supported-authentication-methods> </client-authentication> </ssh-server-parameters> </ssh> </endpoint> </listen> </netconf-server>

And I only want to edit <admin-idle-slope>1000000</admin-idle-slope> which is near the beginning. I do not want to edit the entire file, and I want to edit it while the server is running. Is there a way to do that? I tried using susrepocfg --rpc=nano but I keep getting formatting errors.

[jktjkt]

I know that the general idea of netconf is to edit the candidate datastore, and then commit the changes to the running datastore.

That's not necessarily true. There are many way how a NETCONF server might implement datastores, and for example sysrepo + netopeer2 make it trivial to edit either startup or running. It's just one parameter in an incoming NETCONF <edit-config>.

Is there a way to edit only parts of a datastore without accessing the xml file with sysrepocfg?

sysrepocfg is not related to NETCONF in anyway; it's a local CLI tool which make it possible to access the same "database" backend of the netopeer2 server as you can access via the NETCONF protocol.

And I only want to edit 1000000 which is near the beginning.

The netopeer2 server is "just" a NETCONF frontend on top of sysrepo, the YANG database. In NETCONF, if you want to set a leaf like this to some value, you send an <edit-config> RPC. You should probably read that entire RFC if you're interested in learning how NETCONF works.

I do not want to edit the entire file, and I want to edit it while the server is running.

In NETCONF, there's no concept of XML files. What's probably confusing you is the sysrepocfg tool which can show you the content of a YANG datastore in XML (or in JSON) as a single file, and which makes it also possible for you to edit this file locally in a text editor. However, that's an implementation detail of this SW, and it is not related to NETCONF in any way.

[anoikob]

Thank you for the reply. What confuses me is that according to the netoper2-cli documentation, edit-config also needs --config=[<file>] . In the doc, it says that if a file is not specified, the configuration can be read from the standard input, which should mean my keyboard. This leads me to think that I can just send a RPC message like --config=<admin-idle-slope>10098000</admin-idle-slope> (after specifying the target datastore of course) . However, that's not the case.
Further reading on the RFC-6241 shows some examples of the edit-config operation syntax. I will use this example to illustrate my confusion:

From what I gather, the message needs to have a similar kind of syntax. Since identation is not important for anything other than readability, I should be able to do something like edit-config --target candidate --config=<rpc message-id="102" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><edit-config><target><running/></target><config><interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"><interface><name>eth0</name><bridge-port xmlns="urn:ieee:std:802.1Q:yang:ieee802-dot1q-bridge"><cbsa xmlns="urn:ieee:std:802.1Q:yang:ieee802-dot1q-cbsa-bridge"><cbsa-parameter-table><admin-idle-slope>2000000</admin-idle-slope></cbsa-parameter-table></cbsa></bridge-port></interface></interfaces></config></edit-config></rpc> all in a single line in netopeer2-cli.
But once again, that does not work, and I get an error reading cmd_editconfig: Unable to open the local datastore file "<rpc" (No such file or directory).

Am I missing something? Can edit-config in netopeer2-cli work by providing a direct RPC message?

[michalvasko]

What the documentation says is right and it should not be confusing. You either specify a file or the configuration will be read from input (with the help of a text editor). You were trying to "specify a file" (there is a parameter for --config) which was actually the configuration itself. To read the configuration from input, use just --config.

Seems you do not understand how getopt(3) works but it is used by 99% parameter processing so you should get familiar with it. This issue has nothing to do with our tools directly.

[anoikob]

Ok I resolved the issue. It would seem that just entering edit-config --target candidate --config and then just pressing enter opens up the vim editor so I can send the configuration. No idea how I was supposed to know that though, but hey at least it worked. Thanks for your time, everyone!