Device(Programmability Using(YANG(Development(Kit · [email protected] NETCONF RESTCONF gRPC XML...

Santiago Álvarez

June 2016

Device Programmability Using YANG Development Kit

@111pontes

[email protected]

NETCONF gRPCRESTCONF

XML JSON

Model-Driven Programmability Stack

Model-Driven APIsYANG Development Kit (YDK)

YANG Models (native, open, common)

XR Data Model Database

App1 App2 App3

Models

Encoding

Protocol

APIs

Apps

SSH HTTPTransport

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• Model based, structured, computer friendly• Multiple model types (native, common, OpenConfig, IETF, etc.)• Models decoupled from transport, protocol end encoding• Choice of transport, protocol and encoding• Model-driven APIs for abstraction and simplification• Wide standard support while leveraging open source

Benefits of Model-Driven Programmability

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• Simplify app development

• Abstract transport, encoding, modeling language

• API generated from YANG model

• One-to-one correspondence between model and class hierarchy

• Multi-language (Python, C++, Ruby, Go, etc.)

Model-Driven APIs

4

YANG ModelClass Hierarchy

(Python, C++, Ruby, Go)

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• Model structures data (config and operational) as a tree

• Models files are self-documented and ship with devices

• Cisco IOS XR supports 180+ YANG models (config and operational) in release 6.0.1

• Native models provide most coverage

• OpenConfig and IETF models are mapped to native models

• OpenConfig (BGP, Routing Policy, MPLS, Interfaces)

XR Data Models

Native / Common OpenConfig / IETF

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Generation of Model-Driven APIs Using YANG Development Kit (YDK)

YANGYANGYANG

Data Models (YANG)

APIGenerator

DocsPython

C++

: :

Ruby

go

Docs

Docs

Docs

C♯ Docs

YDK-gen

YDK-PyYDK

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YDK-Py API Structure

Models(BGP, IS-IS, etc)

Services(CRUD, NETCONF, etc.)

Providers(NETCONF, Codec, etc.)

• Models group Python APIs created for each YANG model

• Services perform operations on model objects (interface)

• Providers implement services (implementation)

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• YDK service will automatically perform local (client-side) validation

• Type check (enum, string, etc.)

• Value check (range, pattern, etc.)

• Semantic check (key uniqueness/presence, mandatory leafs, etc.)

• Model deviation check

Client-Side Validation

Application(client)

Device(server)

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# Cisco YDK-‐Py OC-‐BGP “Hello world”from ydk.services import CRUDServicefrom ydk.providers import NetconfServiceProviderfrom ydk.models.bgp import bgp

if __name__ == "__main__":provider = NetconfServiceProvider(address=10.0.0.1,

port=830,username=“admin”,password=“admin”,protocol=“ssh”)

crud = CRUDService() # create CRUD servicebgp = bgp.Bgp() # create oc-‐bgp objectbgp.global_.config.as_ = 65000 # set local AS numbercrud.create(provider, bgp) # create on NETCONF deviceprovider.close()exit()

# End of script

A YDK-Py “Hello World” Using OC-BGP

module: openconfig-‐bgp+-‐-‐rw bgp!

+-‐-‐rw global| +-‐-‐rw config| | +-‐-‐rw as| | +-‐-‐rw router-‐id? | +-‐-‐ro state| | +-‐-‐ro as| | +-‐-‐ro router-‐id? | | +-‐-‐ro total-‐paths? | | +-‐-‐ro total-‐prefixes?

...

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Releases

• CRUD service, NETCONF provider

• Python APIs for XR native and OpenConfig models

• Client-side validation

• Netconf service

• Codec service (py2xml / xml2py)

• Validation of YANG deviations

• Improved error reporting

• Improved logging

• Model bundles

• Additional languages (Ruby, C++)

• Enhanced error reporting

• Model-driven telemetry

• YDK app maker

• YANG RPC support

0.3.0 0.4.0 Roadmap0.4.1

• Netconf service

• Codec service (py2xml / xml2py)

• Validation of YANG deviations

• Improved error reporting

• Improved logging

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carreras

YDK Demo Testbed

domingo pavarotti

YDK Sample Apps

NETCONF Management network

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Cisco Live Las Vegas

• LTRSPG-2601 - Cisco IOS XR Programmability Lab (4hrs)

• DEVNET-2057 - Ok, We Got YANG Data Models, Now What?

• YDK Self-paced Lab

Upcoming Events

13

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GitHub

• YDK Python API – YDK-Py (https://git.io/vaWsg)

• YDK-Py sample apps (https://git.io/vaw1U)

• YDK Generator – YDK-gen (https://git.io/vaw1M)

• Cisco IOS XR YANG models (https://git.io/vg7fk)

• YANG Explorer (https://git.io/vg7Jm)

DevNet

• YDK at DevNet (https://developer.cisco.com/site/ydk/)

• Cisco IOS XR 6.0 at DevNet (https://developer.cisco.com/site/ios-xr/)

Resources

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YDK Sandboxes

• Ubuntu YDK-PY Vagrant box (https://git.io/vaw1U)

• YDK on dCloud.cisco.com – Coming soon

YDK Support

• Cisco support community (https://communities.cisco.com/community/developer/ydk)

Other

• Blog (http://blogs.cisco.com/author/santiagoalvarez)

• Twitter (@111pontes)

Resources (cont.)

15

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Programming

• Codecademy: Learn to code interactively (https://www.codecademy.com)

• Code School: Learn by Doing (https://www.codeschool.com)

• Learning Git and GitHub (https://git.io/vTmHO)

Resources (cont.)

16

Thank you!

+

Backup

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carreraslo0172.16.255.2/32

YDK Demo Testbed

domingo

172.16.1.0/31

lo0172.16.255.1/32

pavarotti

lo0172.16.255.3/32

director

10.30.110.82 10.30.110.83 10.30.110.84

10.30.110.85

.0 .1 .4 .5172.16.1.0/31 172.16.1.0/31

.2 .3

gi0/0 gi0/1 gi0/0 gi0/1

gi0/1 gi0/0

YDK Sample Apps

NETCONF

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• Modeling language (initially for NETCONF)

• Main node types• Leaf – node with name and value of certain type (no children)

• Leaf list – sequence of leafs• Container – groups nodes and has no value

• List – Sequence of records with key leafs

• Deviations document data not implemented in non-native model

YANG

Leaf

Node without a valueNode with a value

Leaf list

Container(grouping)

Container(presence)

List

key

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YANG Model Example

container community-‐sets {description “Container for community sets";list community-‐set {key community-‐set-‐name;description "Definitions for community sets";leaf community-‐set-‐name {type string;description "name of the community set";

}leaf-‐list community-‐member {type string {pattern '([0-‐9]+:[0-‐9]+)';

}description "members of the community set";

}}

}

community-‐set CSET165172:1,65172:2,65172:3

end-‐set!community-‐set CSET10

65172:10,65172:20,65172:30

end-‐set!

YANG CLI

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Model Data Example

<community-‐sets><community-‐set>

<community-‐set-‐name>CSET1</community-‐set-‐name><community-‐member>65172:1</community-‐member><community-‐member>65172:2</community-‐member><community-‐member>65172:3</community-‐member>

</community-‐set><community-‐set>

<community-‐set-‐name>CSET10</community-‐set-‐name><community-‐member>65172:10</community-‐member><community-‐member>65172:20</community-‐member><community-‐member>65172:30</community-‐member>

</community-‐set></community-‐sets>



65172:10,65172:20,65172:30

end-‐set!

XML CLI

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Model Data Example



65172:10,65172:20,65172:30

end-‐set!

{ "community-‐sets": {"community-‐set": [

{ "community-‐set-‐name": "CSET1","community-‐member": [

"65172:1","65172:2","65172:3" ]

},{ "community-‐set-‐name": "CSET10",

"community-‐member": ["65172:10","65172:20","65172:30" ]

}]

}}

JSON CLI

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NETCONF• Rich functionality to manage configuration and operational (state) data

• Operations defined as RPCs (request / reply) in XML

• Client/app initiate request towards server/device

• Supports running, candidate and startup configurations

• Capability exchange during session initiation

NETCONF Protocol Overview

XML

YANG

SSH

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Main NETCONF Protocol OperationsOperation Descriptionget-config Retrieve all or part of a specified configuration

edit-configLoads all or part of a specified

configuration (merge, replace, create, delete, remove)

get Retrieve all or part of running configuration and device operational data

get-schema Retrieve device schema (model)

lock Lock entire configuration datastore (e.g. candidate)

unlock Remove lock on entire configuration datastore (e.g.candidate)

close-session Request graceful session termination

Device(Programmability Using(YANG(Development(Kit · [email protected] NETCONF RESTCONF gRPC XML...

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