The Definitive Introduction to Falcon

The Deﬁnitive Introduction to Falcon Alejandro Cabrera ([email protected]) November 13,
2013 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

from pprint import pprint if __name__ == ’__main__’: meta =
{ ’author’ : ’Alejandro Cabrera’, ’email’ : ’[email protected]’, ’objective’ : ’Introduce Falcon!’ } pprint(meta) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

About Me Software developer @ Rackspace Likes: Haskell, Python, Linux,
open-source, automation, quality, cordiality Dislikes: Proprietary, manual processes, hostility Github: cabrera Twitter: @cppcabrera IRC: alcabrera @ freenode Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon Is. . . Falcon is a high-performance Python framework
for building cloud APIs. It encourages the REST architectural style, and tries to do as little as possible while remaining highly effective. Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon Is. . . A simple web framework Alejandro Cabrera
([email protected]) The Deﬁnitive Introduction to Falcon

Falcon Is. . . A simple web framework WSGI/Python Alejandro
Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon Is. . . A simple web framework WSGI/Python Fast
Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Why Falcon? Simple Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to
Falcon

Why Falcon? Simple Productive Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction
to Falcon

Why Falcon? Simple Productive Fast Alejandro Cabrera ([email protected]) The Deﬁnitive
Introduction to Falcon

So Falcon Is Fast. . . Alejandro Cabrera ([email protected]) The
Deﬁnitive Introduction to Falcon

Falcon Is Fast Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to
Falcon

Let’s Talk About Falcon Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction
to Falcon

But First. . . HTTP Primer Alejandro Cabrera ([email protected]) The

But First. . . HTTP Primer WSGI Primer Alejandro Cabrera

HTTP: In Short HTTP/1.1 200 OK Connection: close Content-Length: 119
Content-Location: /v1/queues Content-Type: application/json; charset=utf-8 Date: Tue, 12 Nov 2013 19:45:55 GMT Server: gunicorn/18.0 { "queues": [ { "href": "/v1/queues/taco", "name": "taco" } ] } Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Status Codes Five classes: 100, 200, 300, 400, 500

100: Informational Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

100: Informational 200: Good - it worked Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

100: Informational 200: Good - it worked 300: Redirections Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

100: Informational 200: Good - it worked 300: Redirections 400: Client-side oops Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

100: Informational 200: Good - it worked 300: Redirections 400: Client-side oops 500: Server side error Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Response Status HTTP/1.1 200 OK Alejandro Cabrera ([email protected]) The

HTTP: Headers Like a dictionary Alejandro Cabrera ([email protected]) The Deﬁnitive

HTTP: Headers Like a dictionary Many standard-deﬁned, some used by
convention Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Headers Connection: close Content-Length: 119 Content-Location: /v1/queues Content-Type: application/json;
charset=utf-8 Date: Tue, 12 Nov 2013 19:45:55 GMT Server: gunicorn/18.0 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Body Actual data Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction
to Falcon

HTTP: Body Actual data Can be anything Alejandro Cabrera ([email protected])
The Deﬁnitive Introduction to Falcon

HTTP: Body Actual data Can be anything Good idea -
set Content-Type to be descriptive Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

set Content-Type to be descriptive json -> application/json Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

set Content-Type to be descriptive json -> application/json html -> text/html Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

set Content-Type to be descriptive json -> application/json html -> text/html msgpack -> application/x-msgpack Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

set Content-Type to be descriptive json -> application/json html -> text/html msgpack -> application/x-msgpack binary -> application/octet-stream Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Body { "links": [ { "href": "/v1/queues?marker=taco", "rel": "next"
} ], "queues": [ { "href": "/v1/queues/taco", "name": "taco" } ] } Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Request A client makes a request Alejandro Cabrera ([email protected])

HTTP: Request A client makes a request The request carries
information that a server uses to reply Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

information that a server uses to reply What kind of request is it? (HTTP verb) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

information that a server uses to reply What kind of request is it? (HTTP verb) How large is my payload? (Content-Length) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

information that a server uses to reply What kind of request is it? (HTTP verb) How large is my payload? (Content-Length) What type of data am I sending? (Content-Type) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

information that a server uses to reply What kind of request is it? (HTTP verb) How large is my payload? (Content-Length) What type of data am I sending? (Content-Type) What type of data can I receive? (Accept) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Response A server makes a response Alejandro Cabrera ([email protected])

HTTP: Response A server makes a response The response also
carries metadata Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

carries metadata Was it successful? (status code) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

carries metadata Was it successful? (status code) What type of data am I replying with? (Content-Type) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Verbs This request/response cycle is further controlled by HTTP
verbs: Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

verbs: HEAD Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

verbs: HEAD GET Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

verbs: HEAD GET PUT Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

verbs: HEAD GET PUT POST Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

verbs: HEAD GET PUT POST DELETE Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

verbs: HEAD GET PUT POST DELETE PATCH Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Routing Finally, the server needs to know what you
want to access to respond Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Routing Finally, the server needs to know what you
want to access to respond A route looks like: Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP: Routing GET /v1/queues HTTP/1.1 Host: localhost:8000 Alejandro Cabrera ([email protected])

HTTP: Routing # ||| Method GET /v1/queues HTTP/1.1 Alejandro Cabrera

HTTP: Routing # ||| Route GET /v1/queues HTTP/1.1 Alejandro Cabrera

HTTP: Routing # ||| Protocol GET /v1/queues HTTP/1.1 Alejandro Cabrera

HTTP: Routing (Host) Host: localhost:8000 Alejandro Cabrera ([email protected]) The Deﬁnitive

HTTP: Routing The Host tells us which server to access

The URI tells us what resource to access Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

The URI tells us what resource to access The URI can also have a query string (more on this later) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

An Aside: REST REST is a style of writing web
applications Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

applications In short, it means - follow the HTTP standard Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

applications In short, it means - follow the HTTP standard Key points: Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

applications In short, it means - follow the HTTP standard Key points: HEAD|GET are read-only, pure, safe operations Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

applications In short, it means - follow the HTTP standard Key points: HEAD|GET are read-only, pure, safe operations PUT|DELETE modify a resource, but should be idempotent Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

applications In short, it means - follow the HTTP standard Key points: HEAD|GET are read-only, pure, safe operations PUT|DELETE modify a resource, but should be idempotent POST creates an entity subordinate to the given URI Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

applications In short, it means - follow the HTTP standard Key points: HEAD|GET are read-only, pure, safe operations PUT|DELETE modify a resource, but should be idempotent POST creates an entity subordinate to the given URI PATCH modiﬁes a portion of an entity Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Now For: WSGI Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to
Falcon

Now For: WSGI (Not Whiskey) Alejandro Cabrera ([email protected]) The Deﬁnitive

WSGI: What? A Pythonic approach to HTTP application development Alejandro

WSGI: What? A Pythonic approach to HTTP application development Takes
HTTP headers and metadata and stuﬀs them in dictionaries Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP headers and metadata and stuﬀs them in dictionaries Takes body content and stores it as a stream Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

HTTP headers and metadata and stuﬀs them in dictionaries Takes body content and stores it as a stream Think of it as: HTTP made easy Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

WSGI: Hello World def hello(env, start_response): print(env[’PATH_INFO’]) status = ’200
OK’ headers = [(’Content-Type’, ’text/plain’)] body = b’hello’ start_response(status, headers) return [body] Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

We Now Return to Our Scheduled Content Alejandro Cabrera ([email protected])

Falcon: WSGI Made Easy Falcon wraps WSGI and gives us:

Easy routing + method not allowed Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Easy routing + method not allowed Request/response objects Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Easy routing + method not allowed Request/response objects Automatic header setting Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Easy routing + method not allowed Request/response objects Automatic header setting Clean, consistent exceptions (400s, 500s) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Easy routing + method not allowed Request/response objects Automatic header setting Clean, consistent exceptions (400s, 500s) Classes to express responders Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Hello World import falcon class Hello(object): def on_get(self, request,
response): response.body = b’hello’ response.status = falcon.HTTP_200 app = falcon.API() app.add_route(’/’, Hello()) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Request Objects Contain at least the following information: Alejandro

Falcon: Request Objects Contain at least the following information: path
- /v1/queues Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True content length - how long is the body? Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True content length - how long is the body? content type Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True content length - how long is the body? content type uri - localhost:8000/v1/queues?detailed=True Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True content length - how long is the body? content type uri - localhost:8000/v1/queues?detailed=True relative uri - /v1/queues?detailed=True Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True content length - how long is the body? content type uri - localhost:8000/v1/queues?detailed=True relative uri - /v1/queues?detailed=True More! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

- /v1/queues query string - detailed=True content length - how long is the body? content type uri - localhost:8000/v1/queues?detailed=True relative uri - /v1/queues?detailed=True More! Also has methods for handling query params! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Response Objects Responses have: Alejandro Cabrera ([email protected]) The Deﬁnitive

Falcon: Response Objects Responses have: body - set this to
return content to the client Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

return content to the client location - sets Location header Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

return content to the client location - sets Location header content type Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

return content to the client location - sets Location header content type etag Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

return content to the client location - sets Location header content type etag set header(s) - custom header handling Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

return content to the client location - sets Location header content type etag set header(s) - custom header handling More! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API API == zip(routes, resources) Alejandro Cabrera ([email protected])

Crafting an API API == zip(routes, resources) Route: a URI
associated with one or more HTTP verbs Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

associated with one or more HTTP verbs Resource: a responder that contains application logic Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

associated with one or more HTTP verbs Resource: a responder that contains application logic Put them together! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

associated with one or more HTTP verbs Resource: a responder that contains application logic Put them together! One resource per route (usually) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

associated with one or more HTTP verbs Resource: a responder that contains application logic Put them together! One resource per route (usually) Let’s practice with. . . Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog — Alejandro Cabrera ([email protected]) The Deﬁnitive

Crafting an API: MultiBlog It helps to layout the routes
and resources before writing even a single line of code Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog It helps to layout the routes
and resources before writing even a single line of code Let’s do that now Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog GET /v1 GET /v1/health GET /v1/stats

GET /v1/authors POST /v1/authors Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

GET /v1/authors POST /v1/authors GET /v1/authors/{author} PATCH /v1/authors/{author} DELETE /v1/authors/{author} Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

GET /v1/authors POST /v1/authors GET /v1/authors/{author} PATCH /v1/authors/{author} DELETE /v1/authors/{author} GET /v1/blog/{author} POST /v1/blog/{author} Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog GET /v1/authors POST /v1/authors GET /v1/authors/{author}
PATCH /v1/authors/{author} DELETE /v1/authors/{author} GET /v1/blog/{author} POST /v1/blog/{author} GET /v1/blog/{author}/{post} PATCH /v1/blog/{author}/{post} DELETE /v1/blog/{author}/{post} Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog # Management routes GET /v1 GET
/v1/health GET /v1/stats Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog # Listing and creating authors GET
/v1/authors POST /v1/authors Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog # Working with specific authors GET
/v1/authors/{author} PATCH /v1/authors/{author} DELETE /v1/authors/{author} Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog # Reading blog details, creating an
entry GET /v1/blog/{author} POST /v1/blog/{author} Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Crafting an API: MultiBlog # Working with existing posts GET
/v1/blog/{author}/{post} PATCH /v1/blog/{author}/{post} DELETE /v1/blog/{author}/{post} Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource Resources are classes that serve as
responders Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

responders Example follows: we’ll create a BlogEntry resource! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

responders Example follows: we’ll create a BlogEntry resource! Expresses part of the “existing posts” routes Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): def __init__(self, db_client): self._post_ctrl
= db_client Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

= db_client def on_get(self, request, response, author, post): content = self._post_ctrl.get(author, post) if not content: raise falcon.exceptions.HTTPNotFound() response.content_type = ’application/json’ response.body = content[’body’] Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

= db_client def on_get(self, request, response, author, post): content = self._post_ctrl.get(author, post) if not content: raise falcon.exceptions.HTTPNotFound() response.content_type = ’application/json’ response.body = content[’body’] def on_delete(self, request, response, author, post): self._post_ctrl.delete(author, post) response.status = falcon.HTTP_204 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

= db_client Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): # ||| responds to
GET requests def on_get(self, request, response, author, post): content = self._post_ctrl.get(author, post) if not content: raise falcon.exceptions.HTTPNotFound() response.content_type = ’application/json’ response.body = content[’body’] Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): def on_get(self, request, response,
author, post): ... # ||| Returning a 404 if not content: raise falcon.exceptions.HTTPNotFound() ... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): def on_get(self, request, response,
author, post): ... # ||| user-visible response: 200 OK by default response.content_type = ’application/json’ response.body = content[’body’] Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): # ||| Responds to
DELETEs def on_delete(self, request, response, author, post): self._post_ctrl.delete(author, post) response.status = falcon.HTTP_204 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): # ||| Request object
def on_get(self, request, response, author, post): ... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): # ||| Response object
def on_get(self, request, response, author, post): ... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): # ||| URI template
args def on_get(self, ..., author, post): ... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Crafting a Resource class BlogEntry(object): def on_patch(...): pass Alejandro

Falcon: Crafting a Resource class BlogEntry(object): def on_patch(...): pass #
Left as an exercise for the reader! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Exposing the API Here, we come back to routes

Falcon: Exposing the API Here, we come back to routes
To connect a resource to a route. . . Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Exposing the API # blog.py app = falcon.API() app.add_route(’/v1/blog/{author}/{post}’,
BlogEntry(db_client)) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Exposing the API # ||| Falcon’s API object app
= falcon.API() Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Exposing the API # ||| The route app.add_route(’/v1/blog/{author}/{post}’, ...)

Falcon: Exposing the API # ||| The responder app.add_route(..., BlogEntry(db_client))

Falcon: Exposing the API # ||| URI templates # |||
passed as param to responder app.add_route(’/v1/blog/{author}/{post}’, ...) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Making it Fly Now we have to run it
For this demo, we’ll use gunicorn Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Make it Fly $ pip install gunicorn ... Alejandro

Falcon: Make it Fly $ pip install gunicorn ... Successfully
installed gunicorn Cleaning up... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Make it Fly $ gunicorn blog:app Alejandro Cabrera ([email protected])

Falcon: Make it Fly $ gunicorn blog:app [INFO] Starting gunicorn
18.0 [INFO] Listening at: http://127.0.0.1:8000 (6194) [INFO] Using worker: sync [INFO] Booting worker with pid: 6199 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Is It Flying Yet? Alejandro Cabrera ([email protected]) The Deﬁnitive

Falcon: Manual Testing Allow me to recommend httpie: Alejandro Cabrera

Falcon: Manual Testing Allow me to recommend httpie: It’s built
on python-requests Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

on python-requests It’s human-friendly Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

on python-requests It’s human-friendly It’s easy to install Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

on python-requests It’s human-friendly It’s easy to install It’s well-behaved and handles HTTP really well Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Manual Testing $ pip install httpie ... Alejandro Cabrera

Falcon: Manual Testing $ pip install httpie ... Successfully installed
httpie Cleaning up... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Manual Testing $ http get localhost:8000/v1/blog/alej/1 Alejandro Cabrera ([email protected])

Falcon: Manual Testing $ http get localhost:8000/v1/blog/alej/1 HTTP/1.1 200 OK
Connection: close Content-Type: application/text Date: Tue, 12 Nov 2013 20:13:58 GMT Server: gunicorn/18.0 Transfer-Encoding: chunked Cool story, bro. Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Manual Testing $ http get localhost:8000/v1/alej/1 Alejandro Cabrera ([email protected])

Falcon: Manual Testing $ http get localhost:8000/v1/alej/1 HTTP/1.1 404 Not
Found Connection: close Content-Length: 0 Date: Tue, 12 Nov 2013 20:49:17 GMT Server: gunicorn/18.0 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Manual Testing $ http post localhost:8000/v1/blog/alej/1 Alejandro Cabrera ([email protected])

Falcon: Manual Testing $ http post localhost:8000/v1/blog/alej/1 HTTP/1.1 405 Method
Not Allowed Allow: GET Connection: close Content-Length: 0 Date: Tue, 12 Nov 2013 20:50:02 GMT Server: gunicorn/18.0 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Manual Testing $ http delete localhost:8000/v1/blog/alej/1 Alejandro Cabrera ([email protected])

Falcon: Manual Testing $ http delete localhost:8000/v1/blog/alej/1 HTTP/1.1 204 No
Content Connection: close Date: Tue, 12 Nov 2013 20:50:35 GMT Server: gunicorn/18.0 Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Automated Testing Manual testing is kinda cool. . .

. . . but not ideal for long-term maintenance Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

. . . but not ideal for long-term maintenance Unit testing with Falcon is pretty easy Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

. . . but not ideal for long-term maintenance Unit testing with Falcon is pretty easy Functional testing with Falcon + python-requests is doable, as well Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) First, let’s start with
a base class to help us simulate requests Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) class TestBase(unittest.TestCase): def setUp(self):
self.app = blog.app self.srmock = falcon.testing.StartResponseMock() Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

self.app = blog.app self.srmock = falcon.testing.StartResponseMock() def simulate_request(self, path, ...): env = falcon.testing.create_environ( path=path, **kwargs ) return self.app(env, self.srmock) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

self.app = blog.app self.srmock = falcon.testing.StartResponseMock() def simulate_request(self, path, ...): env = falcon.testing.create_environ( path=path, **kwargs ) return self.app(env, self.srmock) def simulate_get(self, *args, **kwargs): kwargs[’method’] = ’GET’ return self.simulate_request(*args, **kwargs) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) # ||| unittest as
foundation class TestBase(unittest.TestCase): Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

# ||| your blog API self.app = blog.app self.srmock = falcon.testing.StartResponseMock() Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) class TestBase(unittest.TestCase): # |||
generic request handler def simulate_request(self, path, ...): env = falcon.testing.create_environ( path=path, **kwargs ) return self.app(env, self.srmock) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) class TestBase(unittest.TestCase): def simulate_request(self,
path, ...): # ||| create a mock WSGI environment env = falcon.testing.create_environ( path=path, **kwargs ) return self.app(env, self.srmock) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) class TestBase(unittest.TestCase): # |||
a method for simulating GETs def simulate_get(self, *args, **kwargs): kwargs[’method’] = ’GET’ return self.simulate_request(*args, **kwargs) ... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Base Class) class TestBase(unittest.TestCase): # more
methods, more methods! (just like GET) def simulate_head(self, *args, **kwargs): ... def simulate_put(self, *args, **kwargs): ... def simulate_delete(self, *args, **kwargs): ... def simulate_patch(self, *args, **kwargs): ... def simulate_post(self, *args, **kwargs): ... Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Test) With a handy base class
in hand, let’s actually test this thing! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Test) @ddt.ddt class TestBlogEntry(base.TestBase): def setUp(self):
super(TestBlogEntry, self).setUp() # create a blog post self.entry_path = ’/v1/blog/alej/1’ self.simulate_post(’/v1/blog/alej’) def tearDown(self): self.simulate_delete(’/v1/blog/alej/1’) super(TestBlogEntry, self).tearDown() Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Test) @ddt.ddt class TestBlogEntry(base.TestBase): ... def
test_get_returns_200_when_entry_exists(self): self.simulate_get(self.entry_path) self.assertEqual(self.srmock.status, falcon.HTTP_200) def test_get_returns_404_when_entry_not_found(self): self.simulate_get(’/v1/blog/alej/notfound’) self.assertEqual(self.srmock.status, falcon.HTTP_404) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Test) @ddt.ddt class TestBlogEntry(base.TestBase): ... @ddt.data([self.entry_path,
’/v1/blog/alej/notfound’]) def test_delete_always_returns_204(self, path): self.simulate_delete(path) self.assertEqual(self.srmock.status, falcon.HTTP_204) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Unit Testing (The Test) @ddt.ddt class TestBlogEntry(base.TestBase): ... @ddt.data(’post’,
’put’, ’patch’, ’head’) def test_method_not_allowed_respected(self, method): getattr(self, ’on_’ + method)(self.entry_path) self.assertEqual(self.srmock.status, falcon.HTTP_405) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Run the Tests $ nosetests -v tests/test_blog.py Alejandro Cabrera

Falcon: Run the Tests $ nosetests -v tests/test_blog.py ... Ran
8 tests in 0.008s OK Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Run the Tests Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction
to Falcon

Recap With a basic understanding of HTTP. . . Alejandro

Recap With a basic understanding of HTTP. . . .
. . adding a smidgen of WSGI. . . Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

. . adding a smidgen of WSGI. . . . . . a couple of routes. . . Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

. . adding a smidgen of WSGI. . . . . . a couple of routes. . . . . . and a dash of resources . . . Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

. . adding a smidgen of WSGI. . . . . . a couple of routes. . . . . . and a dash of resources . . . . . . allowed to bake in a test oven for a few minutes . . . Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

. . adding a smidgen of WSGI. . . . . . a couple of routes. . . . . . and a dash of resources . . . . . . allowed to bake in a test oven for a few minutes . . . . . . you, too, can have a Falcon-powered web application! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Quick Takes How do I read the request contents? Alejandro

Quick Takes How do I read the request contents? request.stream.read()

Quick Takes How do I set a header for the
response? Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Quick Takes How do I set a header for the
response? response.set_header(’X-Awesomeness’, ’You’) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Quick Takes Where can I ﬁnd all the errors falcon
can raise? (400s, 500s) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Quick Takes Where can I ﬁnd all the errors falcon
can raise? (400s, 500s) from falcon import exceptions dir(exceptions) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Quick Takes How can I generate an etag? Alejandro Cabrera

Quick Takes How can I generate an etag? import hashlib
md5 = hashlib.md5 response.etag = md5(request.stream.read()).hexdigest() Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Quick Takes How can I retrieve URI query parameters? Alejandro

Quick Takes How can I retrieve URI query parameters? limit
= request.get_param_as_int(’limit’) detailed = request.get_param_as_bool(’detailed’) marker = request.get_param(’marker’) Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Next Steps Write your own application Alejandro Cabrera ([email protected])

Falcon: Next Steps Write your own application Add storage Alejandro

Falcon: Next Steps Write your own application Add storage Learn
about middleware Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

about middleware Leveling up your tests: tox, mock, httpretty Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

about middleware Leveling up your tests: tox, mock, httpretty Contribute! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Falcon: Thanks To These Falconians! Kurt Griffiths (kgriffs) created Falcon
and is its current maintainer. Many thanks to all the mighty fine contributors to the project, listed below by date of contribution: Alejandro Cabrera (cabrera) Chad Lung (chadlung) Josh Brand (joshbrand) Jamie Painter (painterjd) Flavio Percoco (flaper87) Randall Burt (rs-randallburt) Zhihao Yuan (lichray) Ashutosh Das (pyprism) Emanuele Rocca (ema) Flavio Percoco (flaper87) Soren Hansen (sorenh) Alejandro Cabrera ([email protected]) The Definitive Introduction to Falcon

Packages Referenced ddt python-requests falcon httpie nose Alejandro Cabrera ([email protected])

Questions? Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

Thanks! Alejandro Cabrera ([email protected]) The Deﬁnitive Introduction to Falcon

The Definitive Introduction to Falcon

The Definitive Introduction to Falcon

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