Unauthorized interaction with google calendar API v3

Question

I'm in the same situation as this guy (only that my problem is with python): I'm trying to retrieve data using a service account (using this example and after reading this blog entry since my application is a google app) but I get hit with a login required error and I cannot understand why.

Let me represent it with a whole example:

In [1]: import httplib2                                                          
In [2]: from apiclient.discovery import build                                   
In [3]: from oauth2client.client import SignedJwtAssertionCredentials            
In [4]: f = open('abd45679ffg32343-privatekey.p12', 'rb')
In [5]: key = f.read()                                                          
In [6]: f.close()                                                               
In [7]: credentials = SignedJwtAssertionCredentials(                            
        '2127313127654990@developer.gserviceaccount.com', key,                     
        scope=['https://www.googleapis.com/auth/calendar',                      
               'https://www.googleapis.com/auth/calendar.readonly'])            
In [8]: http = httplib2.Http()                                                  
In [9]: http = credentials.authorize(http)                                      
In [10]: service = build(serviceName='calendar', version='v3', http=http,       
   ....:         developerKey='XcddfRgtyt676grggtT')        
2012-05-14 18:24:35,170 INFO  [root][MainThread] URL being requested: https://www.googleapis.com/discovery/v1/apis/calendar/v3/rest                                                              
2012-05-14 18:24:35,170 INFO  [oauth2client.client][MainThread] Attempting refresh to obtain initial access_token
2012-05-14 18:24:35,179 INFO  [oauth2client.client][MainThread] Refresing access_token
In [11]: service.calendarList().list().execute()                                
2012-05-14 18:25:00,418 INFO  [root][MainThread] URL being requested https://www.googleapis.com/calendar/v3/users/me/calendarList?alt=json&key=XcddfRgtyt676grggtT          
---------------------------------------------------------------------------     
HttpError                                 Traceback (most recent call last)     
/home/mariano/Code/Kalendar/rest/kalendar/<ipython-input-12-0cb769615d74> in <module>()
----> 1 service.calendarList().list().execute()                                 
/home/mariano/Code/Kalendar/rest/env/local/lib/python2.7/site-packages/google_api_python_client-1.0beta8-py2.7.egg/apiclient/http.pyc in execute(self, http)                                     
387                                                                         
388       if resp.status >= 300:                                            
--> 389         raise HttpError(resp, content, self.uri)                        
390     return self.postproc(resp, content)                                 
391                                                                         
HttpError: <HttpError 403 when requesting https://www.googleapis.com/calendar/v3/users/me/calendarList?alt=json&key=XcddfRgtyt676grggtT returned "The user must be signed up for Google Calendar.">                   

Any pointers about why is this happening and how to solve it would be greatly appreciate.

Answer 1

I don't think service accounts are available for Calendar API. The service account has no calendar of its own.

Answer 2

Service Accounts are available and work with Calendar API for me.

You need to change your following statement:

credentials = SignedJwtAssertionCredentials('2127313127654990@developer.gserviceaccount.com', key, scope=['https://www.googleapis.com/auth/calendar', 'https://www.googleapis.com/auth/calendar.readonly'])

to

credentials = SignedJwtAssertionCredentials('2127313127654990@developer.gserviceaccount.com', key, scope=['https://www.googleapis.com/auth/calendar', 'https://www.googleapis.com/auth/calendar.readonly'], prn='requestor@domain.com')

Answer 3

The service accounts do work with the Calendar API. You have to also grant access on your domain management as well.

Do as user1260486 and btspierre said, and add the "prn=requestor@domain.com" to the constructor for SignedJWTAssertionCredentials.

Then go to your domain management and add your client_id access to the API.

Here's a walkthrough about it. For the scope specify "https://www.googleapis.com/auth/calendar, https://www.googleapis.com/auth/calendar.readonly"