update the documentation about the web interface

README.rst

@@ -52,3 +52,26 @@ boolean that tels you if this is the communication to the proxied server or
 from it, name is the name of the callable, settings the settings for *this*
 callable and server the server instance (can be useful to look at the global
 settings for instance, and other utilities)
+
+Controlling vaurien from a web interface
+========================================
+
+Sometimes, it is useful to control how the proxy behaves, on a request to
+request basis. Vaurien provides two proxies, the Random one that we defined
+earlier and the OnTheFly one.
+
+The "on the fly" proxy comes with a simple http server to control itself. It
+has two resources that could be useful to you:
+
+    * `/handler [GET, POST]` which allows to either know what is the current
+      handler in use (when doing a `GET`) or to set a new one for the next
+      calls (`POST`). You can for instance do this with the following curl
+      call::
+      
+         $ curl -d"delay" http://localhost:8080/handler -H "Content-Type: text/plain"
+         OK
+            
+    * `/handlers [GET]` returns a list of handlers that are possible to use::
+
+        $ curl http://localhost:8080/handlers -H "Content-Type: application/json"
+        {"handlers": ["delay", "errors", "hang", "blackout", "normal"]}

vaurien/webserver.py

@@ -1,5 +1,6 @@
 """A simple, flask-based webserver able to control how the proxy behaves"""
-from flask import Flask, request, request_started, request_finished
+from flask import (Flask, request, request_started, request_finished,
+                   make_response)
 import json
 
 app = Flask(__name__)
@@ -22,7 +23,9 @@ def update_renderer():
 @app.route('/handlers')
 def list_handlers():
     """List all the available handlers"""
-    return json.dumps({'handlers': app.proxy.handlers.keys()})
+    resp = make_response(json.dumps({'handlers': app.proxy.handlers.keys()}))
+    resp.content_type = 'application/json'
+    return resp
 
 
 # utils