问题
We're having trouble publishing messages to a Google Cloud PubSub topic on Google AppEngine. Using the Application Default credentials works perfect locally. But once it's deployed on Google AppEngine it gives the following error:
<HttpError 403 when requesting https://pubsub.googleapis.com/v1/projects/our-project-id/topics/our-topic:publish?alt=json returned "The request cannot be identified with a project. Please pass a valid API key with the request.">
I would assume that it's will use the service account of app engine to access the PubSub API. Here is the code we used to create the credentials.
credentials = GoogleCredentials.get_application_default()
if credentials.create_scoped_required():
credentials = credentials.create_scoped(['https://www.googleapis.com/auth/pubsub'])
http = httplib2.Http()
credentials.authorize(http)
pubsub_service = build('pubsub', 'v1', http=http)
The error is thrown when publishing the actual message to PubSub.
pubsub_service.projects().topics().publish(topic="projects/out-project-id/topics/out-topic", body = { 'messages' : [ { 'data': base64.b64encode(request.get_data()) }]}).execute()
Not that the same flow works doing API call's to "BigQuery", so it's not a general Google API problem. It seems to be specific to PubSub...
回答1:
It's a rare case of the service account without project id embedded in it. We fixed your service account and you should be good to go now. Sorry for the trouble.
来源：https://stackoverflow.com/questions/32582434/google-cloud-pubsub-authentication-error-from-app-engine