firebase_token_generator.py

import argparse
import json
import urllib2

import firebase_admin
from firebase_admin import credentials, auth

# Configuration ================================================================
DATABASE_URL = "https://[PROJECT_ID].firebaseio.com/"
# Download from
# Firebase Console > Settings > Service Accounts > Generate New Private key
PATH_TO_PRIVATE_KEY = "local/path/to/key.json"
# Copy from
# Firebase Console > Settings > General > Web API Key
API_KEY = "[WEB_API_KEY]"
# ==============================================================================

cred = credentials.Certificate(PATH_TO_PRIVATE_KEY)
default_app = firebase_admin.initialize_app(cred, {"databaseURL": DATABASE_URL})


def get_token(uid):
  """Return a Firebase ID token dict from a user id (UID).

  Returns:
    dict: Keys are "kind", "idToken", "refreshToken", and "expiresIn".
    "expiresIn" is in seconds.

    The return dict matches the response payload described in
    https://firebase.google.com/docs/reference/rest/auth/#section-verify-custom-token

    The actual token is at get_token(uid)["idToken"].
  """
  token = auth.create_custom_token(uid)
  data = {
    'token': token,
    'returnSecureToken': True
  }

  url = "https://www.googleapis.com/identitytoolkit/v3/relyingparty" \
        "/verifyCustomToken?key={}".format(API_KEY)

  req = urllib2.Request(url,
                        json.dumps(data),
                        {'Content-Type': 'application/json'})
  response = urllib2.urlopen(req).read()

  return json.loads(response)


if __name__ == "__main__":
  parser = argparse.ArgumentParser(description="Generate a Firebase ID token "
                                               "from a user id (UID).")
  parser.add_argument("uid", help="Firebase User ID (UID)", type=str)
  args = parser.parse_args()

  print get_token(args.uid)["idToken"]