Example REST service using Connexion Swagger-first Python library: includes schema validation and OAuth 2
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Connexion Example REST Service

This example application implements a very basic "pet shop" REST service using the Connexion Python library.

Connexion is a framework on top of Flask to automagically handle your REST API requests based on Swagger 2.0 Specification files in YAML.


This example application shows various features supported by the Connexion library:

  • mapping of REST operations to Python functions (using the operationId in swagger.yaml)
    • maps path, query and body parameters to keyword arguments
  • bundled Swagger UI (served on /ui/ path)
  • automatic JSON serialization for application/json content type
  • schema validation for the HTTP request body and query parameters:
    • required object properties
    • primitive JSON types (string, integers, etc)
    • date/time values
    • string lengths
    • minimum/maximum values
    • regular expression patterns
  • gevent WSGI server
  • OAuth2 protection


The example application only needs very few files:

  • swagger.yaml: the pet shop REST API Swagger definition
  • app.py: implementation of the pet shop operations with in-memory storage
  • requirements.txt: list of required Python libraries
  • Dockerfile: to build the example as a runnable Docker image
  • test.sh: shell script to execute example HTTP requests against the pet shop API

Running Locally

You can run the Python application directly on your local operating system:

$ sudo pip3 install -r requirements.txt
$ ./app.py # start the HTTP server
$ xdg-open http://localhost:8080/ui/
$ ./test.sh # do some test HTTP requests

Running with Docker

You can build the example application as a Docker image and run it:

$ docker build -t connexion-example .
$ docker run -d -p 8080:8080 connexion-example
$ ./test.sh # do some test HTTP requests

Using OAuth2 Security

To enable OAuth2 security (token verification), you need to pass the URL to the "tokeninfo" endpoint:

$ docker run -d -p 8080:8080 -e HTTP_TOKENINFO_URL=https://auth.example.org/tokeninfo connexion-example

Using Connexion with a WSGI container

You can use the Flask WSGI app with any WSGI container, e.g. using Flask with uWSGI:

$ sudo pip3 install uwsgi
$ uwsgi --http :8080 -w app

You can run uwsgi with a large number of worker processes to get high concurrency. This obviously makes no sense for the in-memory pet store example (every worker would have its own pet store dictionary):

$ uwsgi --http :8080 -w app -p 16  # use 16 worker processes

See the uWSGI documentation for more information.