2. Plugs: https://learninglabs.cisco.com Coding 101 Lab Coding 102 Lab
Use Coding 102 for system setup help:
Chrome
A text editor (text wrangler, notepad ++, sublime text etc.)
Postman REST Client --
Python
Go to command prompt and type python
Install instructions --
Python Requests library --

3. More Plugs: learninglabs.cisco.com
Check these out

4. What We
Know

5. Easier Network Element Management
REST / JSON
is the answer of the day
Customers Demand
Easier Network Element Management

6. The Evolution of Device Interaction
Bootstrap
Configure
Extend
Plug n Play
PoAP
Smart Install
Auto Install
CLI
Controllers
Openstack
Puppet/Chef
REST
JSON RPC
NETCONF
CLI
I2RS
onePK
OpenFlow
Onbox Python
EEM
Evolving
First – categorize the different APIs/protocols/frameworks into buckets. Some cross buckets, some enable technologies in other buckets, but in general, they are all optimized for particular kinds of tasks.
Bootstrap – day one configuration
Configure – into the capabilities of the network device
Extending what you can do with the device. Dynamic programming, also sometimes used to do configuration
Generally speaking optimized for extension
Look from bottom up. CLI is tool of choice for bootstrap and configure.
Middle bucket is where we want to concentrate on. By far the most things people want is a configurator, and to handle configuration tasks.
Solve immediate pain points
Traditional

7. REST Follows a Familiar Model
Web Browsing
REST API
Twitter: IDs of last five followers
{"ids":[ , , , , , ], "next_cursor":0, "next_cursor_str":"0", "previous_cursor":0, "previous_cursor_str":"0"}
HTTP GET
HTTP GET
HTML
JSON/XML
Here is an example of a rest call to twitter
This is a real return value
Describes how data should be displayed to please human viewer
Describes data in a format applications can understand

8. REST is An Architectural Style (Not a protocol)
REST= REpresentational State Transfer
Proposed by Roy Fielding in 2000
Developed by W3C in parallel with HTTP 1.1
Simple CRUD using HTTP
Stateless client-server model
Uses URIs to identify resources of interest
Rest
its an architectural style, it is not a protocol
it is a suggestion on how to behave
works over crud ( Create, Read, Update, Delete)

9. There Are LOTS of RESTful APIs
Thousands of programs use rest apis

10. Why Does This Matter for Networking?
Easy to use
Why Does This Matter for Networking?
Human Readable
Software Friendly
Large Developer Base
Client Libraries in Many Languages
Lot of people that can program rest
Easy

11. REST: It’s Not Just for Web Services
Products and applications can consume restful apis
Even at cisco
Vmware ucs ucs-director, open daylight

12. REST: Coming Soon to a Device Near You
Supported on CSR1kV since XE 3.10
ASR1K in XE 3.14
Primarily for Config
DNS, NTP, Interface, Routing, ACL, NAT
Some Stats
Interface, CPU, Memory
Runs in a service container
Uses onePK Python APIs under the hood
Seeing experimentation on bringing rest apis to you
Csr1kv
Kind of limited now but being built out

13. Sample: Grab Hosts from APIC-EM
Application Policy Infrastructure Controller (APIC) Enterprise Module (EM)
3rd Party App
Request
Response
3rd Party App
GET rec}
List of Hosts returned in JSON
Cisco APIC-EM
Request
Response

14. Anatomy of a REST Request
Method
GET, POST, PUT, DELETE
URL
Example:
Authentication
Basic HTTP, OAuth, none
Custom Headers
HTTP Headers
Example: Content-Type: application/json
Request Body
JSON or XML containing data needed to complete request
JSON -- JavaScript Object Notation, is a lightweight text-based open standard designed for human-readable data interchange.

15. And what is in the Response?
HTTP Status Codes
200 OK
201 Created
500 Internal Error
Headers
Body
JSON
XML

16. REST in Action: How can I try it?
HTTP clients can help you quickly test web services
Postman -
Firefox RestClient -
Command Line using curl -
SOAPUI
Many IDEs have consoles for testing REST Services built in

18. Cost

19. REST Demo – Using Postman

20. REST Demo – Using Postman

21. REST Demo – Using Postman
Get Hosts
Method: GET
URL:
Get Devices
URL:
Get Policies
URL:
Get Applications
URL:

22. REST DEMO – Using the POST or PUT Method
To send data to a REST service and either create or update data, you will need to use POST or PUT.
Create Policy Example
Method: POST
URL:
Custom Headers: Content-Type: application/json
Request Body: JSON that specifies details of new policy
What if the Content-Type header is missing?
What if there is a mistake in the JSON Request Body?
Handy tool for validating JSON --

23. REST Demo – Using POST or PUT Method
Show what happens if you forget the Content-Type Header

24. First REST call from Python
Source code file: apic-em1.py
#import requests library
import requests
#specify URL
url = '
#Call REST API
response = requests.get(url)
#Print Response
print response.text
More info on requests library -

25. Python Examples
Download Sample Code
Coding 102
apic-em1.py – simple example to get list of hosts
apic-em-helloworld.py – “hello world” type example to show list of devices
learning-lab-basics.py – Retrieves device list and pretty prints JSON
learning-lab-basics-step2.py – Retrieves network device list and parses JSON to display networkDeviceId values
learning-lab-basics-step3.py – Retrieves and lists all devices, hosts, policies and configured applications
learning-lab-create-policy.py – Shows how to create a new policy using the POST Method

26. AD-HOC REST (REST like) Interface
Leverage existing automation technology
Brownfield

27. Bonus
JSON-RPC

28. Comparison: REST/JSON-RPC Similar: Both Send/Receive JSON over HTTP
JSON-RPC (N9K NX-API)
REST (CSR 1000v)
Both send and receive json over http
Sometimes they seem the same
Differences are not that important

29. Comparison: REST/JSON-RPC Different: Resources (URIs)
REST: Many Resources
…/global/banner
…/global/hostname
…/global/reload
…/interfaces/…
…/routing-svc/…
…/nat-svc/…
…/acl/… …
JSON-RPC: Few Resources
Differences between them
Rest operates on the idea of these different resources
acls/interfaces…
Resources for each thing you want to do
Json has much fewer resources
CSR1kV
N9K

30. Different: Methods GET: Retrieve/List PUT: Replace
REST: Standard HTTP Methods
GET: Retrieve/List
PUT: Replace
POST: Create New Entry
DELETE: Delete
JSON-RPC: POST + body method
Rest only uses standard http methods
Json rpc uses post.
And puts information in the body of what you should do

31. JSON-RPC Details
A very simple remote procedure call protocol encoded in JSON, sent over HTTP
JSON RPC Request Properties
method – (string) name of the method to be invoked.
params – (array) objects to be passed as parameters to the defined method.
Id – (any type) used to match the response with request
JSON RPC Response Properties
result - data returned by the invoked method.
error - specified Error code if there was an error invoking the method, otherwise null.
id - id of the corresponding request.

32. NXAPI Switch# conf t Switch(config)# feature nxapi
CLI Interaction with device over HTTP / HTTPS
Input/Output encoded in JSON or XML (key for programmability) [ {
"jsonrpc": "2.0",
"method": "cli",
"params": {
"cmd": "show clock",
"version": 1 },
"id": 1 } ]
Show clock
NXAPI Web Server
(NGINX)
Switch# conf t
Switch(config)# feature nxapi
Switch(config)# exit
HTTP / HTTPS {
"jsonrpc": "2.0",
"result": {
"body": {
"simple_time": "15:00: PST Mon Aug \n" } },
"id": 1

33. NXAPI – Web Sandbox Point browser to IP Address of Network Element
Enter CLI Commands
See formatted input and output

34. NXAPI – Python Generation
Click on the Python button, and the tool will generate python
Interaction code for you.