ReSTful API using Flask Demo

By Dr. Louay Chebib

https://github.com/Netuser-Py/RESTful_API_using_Flask_demo

ReSTful API using Flask Demo

Very flexible and uses an existing protocol like HTLM
REST not constrained to XML, can return XML, JSON, YAML (YAML Ain't Markup Language) or anything else.

https://www.mulesoft.com/resources/api/what-is-rest-api-design

What is ReST?

Representational State Transfer (ReST)

ReSTful API using Flask Demo

• Client-Server Independence
• Stateless and self contained calls independent of each other.
  • State is stored on the client—not on the server
  • Cache reused data on the client with an expiry time
  • Uniform Interface: client & server talk using loose coupling
  • Communicate using HTTP with URI resources, CRUD (Create, Read, Update, Delete), & JSON.
• Layered System provides loose coupling, flexibility, independence, portability of processes & functions & increases security through independence.
• Code on Demand is an optional constraint that is not fully accepted since it allows for the creation & execution of ad-hoc applications.

https://www.mulesoft.com/resources/api/what-is-rest-api-design

Constraints

ReSTful API using Flask Demo

Use urllib to get web page data

https://docs.python.org/3/howto/urllib2.html

Simple BOTs

Demo: urllib_HTML.py

• Get a page of Text
• Dump 2 web pages (HTML)
• Download 2 Images (JPeG)

ReSTful API using Flask Demo

Use paramiko to send commands & get data over SSH (UNIX)

http://docs.paramiko.org/en/2.4/

http://sebastiandahlgren.se/2012/10/11/using-paramiko-to-send-ssh-commands/

Automating SSH

Demo: SSH_paramiko_Demo.py

• Send text to a file
• Get Time/Date and update local Time/Date
• Can Execute command on a remote system!

ReSTful API using Flask Demo

https://blog.miguelgrinberg.com/post/designing-a-restful-api-with-python-and-flask

Simple Flask Server

Demo: Hello World

Server: hello_flask.py

Client: in browser http://127.0.0.1:5000/

or run: urllib_hello.py

ReSTful API using Flask Demo

https://blog.miguelgrinberg.com/post/designing-a-restful-api-with-python-and-flask

https://spin.atomicobject.com/2012/01/17/crud-is-not-rest/

http://confreaks.tv/videos/rockymtnruby2011-crud-is-not-rest-hypermedia-for-y-all

ReST API Flask Server & Client

Demo: "CRUD" like

Run on two Sessions/Devices

Server: rest_server_demo.py

(Flask loves Decorators)

Client: REST_client_demo.py

• Add 2 tasks
• Change a task by key (id)
• Delete a task by key (id)
• List a task by key (id)
• List All tasks

Can also be run with: curl

ReST is not CRUD!

ReSTful API using Flask Demo

Other Items

Document API interface: preferably at server. e.g. swagger

HTTP methods: (POST GET PATCH DELETE) in ReST relate to CRUD

Compare ReST to SOLID

Store values/data to: database, files...

User validation should be hashed/encrypted

Expose Flask Server: nginx.org

Additional alternatives: ZeroMQ, JWT, postman

https://spring.io/understanding/REST

http://blog.restcase.com/restful-api-authentication-basics/