Libsaas: one API to rule them all

APIdays Mediterranea May 2014, Barcelona

Transcript

1. libsaas one API to rule them all Aitor Guevara • @aitorciki
2. Context
3. business data spread across cloud services
4. Ducksboard consumes SaaS APIs to collect and visualize data
7. REST APIs
8. heterogeneous implementations headers, query params, auth, mime types, versioning, error handling…
9. ad-hoc vendor libraries data structures, HTTP handling, sync/async IO, Python versions
10. Enter libsaas
11. abstraction layer on top of heterogeneous SaaS APIs URLs generation, parameters serialization, authentication, …
12. uniform interface Python methods and objects supports Python 2.x, Python 3.x, PyPy
13. extensible implement services as modules base classes, decorators, helpers, documentation auto-generation
14. agnostic isolates modelling from networking
15. Architecture
16. service / resources hierarchy of Python classes
17. filters reusable requests modifiers e.g. pre-built authentication mechanisms
18. executors pluggable HTTP handlers urllib2, Requests, Twisted
19. parsers know how to deserialize responses JSON, XML
20. Example: service definition
21. 1 import json 2 from libsaas import http 3 from libsaas.filters import auth 4 from libsaas.services import base 5 from . import repos 6 7 class GitHub(base.Resource): 8 9 def __init__(self, token_or_username, password=None): 10 self.apiroot = 'https://api.github.com' 11 12 self.add_filter(self.use_json) 13 14 if password is None: 15 self.oauth_token = token_or_username 16 self.add_filter(self.add_authorization) 17 else: 18 self.add_filter(auth.BasicAuth(token_or_username, password)) 19 20 def add_authorization(self, request): 21 request.headers['Authorization'] = 'token {0}'.format(self.oauth_token) 22 23 def use_json(self, request): 24 if request.method.upper() not in http.URLENCODE_METHODS: 25 request.params = json.dumps(request.params) 26 27 def get_url(self): 28 return self.apiroot 29 30 @base.resource(repos.Repo) 31 def repo(self, user, repo): 32 return repos.Repo(self, user, repo) filters definition child resource
22. 1 from libsaas import http 2 from libsaas.services import base 3 from . import resource, repocommits 4 5 class Repo(resource.GitHubResource): 6 7 def __init__(self, parent, user, repo): 8 self.parent = parent 9 self.user = http.quote_any(user) 10 self.repo = http.quote_any(repo) 11 12 def get_url(self): 13 return '{0}/repos/{1}/{2}'.format(self.parent.get_url(), 14 self.user, self.repo) 15 16 def require_collection(self): 17 return False 18 19 def require_item(self): 20 return True 21 22 @base.resource(repocommits.RepoCommits) 23 def commits(self): 24 return repocommits.RepoCommits(self) child resource resource URL
23. 1 from libsaas import http, parsers 2 from libsaas.services import base 3 4 class GitHubResource(base.RESTResource): 5 6 @base.apimethod 7 def get(self, page=None, per_page=None): 8 params = base.get_params(('page', 'per_page'), locals()) 9 request = http.Request('GET', self.get_url(), params) 10 11 return request, parsers.parse_json 12 13 @base.apimethod 14 def update(self, obj): 15 self.require_item() 16 # GitHub uses PATCH for updates 17 request = http.Request('PATCH', self.get_url(), self.wrap_object(obj)) 18 19 return request, parsers.parse_json parse response as JSON
24. 1 from __future__ import print_function 2 from libsaas.services import github 3 4 gh = github.GitHub('my_token') 5 6 repo = gh.repo('aitorciki', 'apidays-demo') 7 8 for commit in repo.commits().get(): 9 msg = commit['commit']['message'] 10 author = commit['commit']['author']['name'] 11 date = commit['commit']['author']['date'] 12 13 print('{0} by {1} on {2}'.format(msg, author, date)) resources tree Python dict HTTP method
25. Questions? Thanks! Aitor Guevara • @aitorciki http://libsaas.net/