google-calendar: Replace deprecated oauth2client library.

Co-authored-by: Vedant Joshi <[email protected]>
Co-authored-by: Pransh Gupta <[email protected]>

Fixes: zulip#847

Author: Niloth-p

pyproject.toml

@@ -62,6 +62,7 @@ module = [
     "apiai.*",
     "feedparser.*",
     "gitlint.*",
+    "google_auth_oauthlib.*",
     "googleapiclient.*",
     "irc.*",
     "mercurial.*",

zulip/integrations/google/get-google-credentials

@@ -1,46 +1,53 @@
 #!/usr/bin/env python3
-import argparse
 import os
 
-from oauth2client import client, tools
-from oauth2client.file import Storage
-
-flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
+from google.auth.transport.requests import Request
+from google.oauth2.credentials import Credentials
+from google_auth_oauthlib.flow import InstalledAppFlow
 
 # If modifying these scopes, delete your previously saved credentials
 # at zulip/bots/gcal/
 # NOTE: When adding more scopes, add them after the previous one in the same field, with a space
 # seperating them.
-SCOPES = "https://www.googleapis.com/auth/calendar.readonly"
+SCOPES = ["https://www.googleapis.com/auth/calendar.readonly"]
 # This file contains the information that google uses to figure out which application is requesting
 # this client's data.
 CLIENT_SECRET_FILE = "client_secret.json"  # noqa: S105
-APPLICATION_NAME = "Zulip Calendar Bot"
 HOME_DIR = os.path.expanduser("~")
 
 
-def get_credentials() -> client.Credentials:
-    """Gets valid user credentials from storage.
+def get_credentials() -> Credentials:
+    """
+    Writes google tokens to a json file, using the client secret file (for the OAuth flow),
+    and the refresh token.
+
+    If the tokens file exists and is valid, nothing needs to be done.
+    If the tokens file exists, but the auth token is expired (expiry duration of auth token
+    is 1 hour), the refresh token is used to get a new token.
+    If the tokens file does not exist, or is invalid, the OAuth2 flow is triggered.
 
-    If nothing has been stored, or if the stored credentials are invalid,
-    the OAuth2 flow is completed to obtain the new credentials.
+    The OAuth2 flow needs the client secret file, and requires the user to grant access to
+    the application via a browser authorization page, for the first run.
 
-    Returns:
-        Credentials, the obtained credential.
+    The fetched tokens are written to storage in a json file, for reference by other scripts.
     """
 
+    creds = None
     credential_path = os.path.join(HOME_DIR, "google-credentials.json")
 
-    store = Storage(credential_path)
-    credentials = store.get()
-    if not credentials or credentials.invalid:
-        flow = client.flow_from_clientsecrets(os.path.join(HOME_DIR, CLIENT_SECRET_FILE), SCOPES)
-        flow.user_agent = APPLICATION_NAME
-        # This attempts to open an authorization page in the default web browser, and asks the user
-        # to grant the bot access to their data. If the user grants permission, the run_flow()
-        # function returns new credentials.
-        credentials = tools.run_flow(flow, store, flags)
-        print("Storing credentials to " + credential_path)
+    if os.path.exists(credential_path):
+        creds = Credentials.from_authorized_user_file(credential_path, SCOPES)
+    if not creds or not creds.valid:
+        if creds and creds.expired and creds.refresh_token:
+            creds.refresh(Request())
+        else:
+            flow = InstalledAppFlow.from_client_secrets_file(
+                os.path.join(HOME_DIR, CLIENT_SECRET_FILE), SCOPES
+            )
+            creds = flow.run_local_server(port=0)
+        with open(credential_path, "w") as token:
+            token.write(creds.to_json())
+    return creds
 
 
 get_credentials()

zulip/integrations/google/google-calendar

@@ -9,23 +9,20 @@ import time
 from typing import List, Optional, Set, Tuple
 
 import dateutil.parser
-import httplib2
 import pytz
-from oauth2client import client
-from oauth2client.file import Storage
 
 try:
-    from googleapiclient import discovery
+    from google.oauth2.credentials import Credentials
+    from googleapiclient.discovery import build
 except ImportError:
-    logging.exception("Install google-api-python-client")
+    logging.exception("Install the required python packages from requirements.txt first.")
     sys.exit(1)
 
 sys.path.append(os.path.join(os.path.dirname(__file__), "../../"))
 import zulip
 
-SCOPES = "https://www.googleapis.com/auth/calendar.readonly"
+SCOPES = ["https://www.googleapis.com/auth/calendar.readonly"]
 CLIENT_SECRET_FILE = "client_secret.json"  # noqa: S105
-APPLICATION_NAME = "Zulip"
 HOME_DIR = os.path.expanduser("~")
 
 # Our cached view of the calendar, updated periodically.
@@ -85,7 +82,7 @@ if not options.zulip_email:
 zulip_client = zulip.init_from_options(options)
 
 
-def get_credentials() -> client.Credentials:
+def get_credentials() -> Credentials:
     """Gets valid user credentials from storage.
 
     If nothing has been stored, or if the stored credentials are invalid,
@@ -97,10 +94,8 @@ def get_credentials() -> client.Credentials:
     """
     try:
         credential_path = os.path.join(HOME_DIR, "google-credentials.json")
-
-        store = Storage(credential_path)
-        return store.get()
-    except client.Error:
+        return Credentials.from_authorized_user_file(credential_path, SCOPES)
+    except ValueError:
         logging.exception("Error while trying to open the `google-credentials.json` file.")
         sys.exit(1)
     except OSError:
@@ -110,8 +105,7 @@ def get_credentials() -> client.Credentials:
 
 def populate_events() -> Optional[None]:
     credentials = get_credentials()
-    creds = credentials.authorize(httplib2.Http())
-    service = discovery.build("calendar", "v3", http=creds)
+    service = build("calendar", "v3", credentials=credentials)
 
     now = datetime.datetime.now(pytz.utc).isoformat()
     feed = (

zulip/integrations/google/requirements.txt

@@ -1,4 +1,5 @@
-httplib2>=0.22.0
-oauth2client>=4.1.3
+google-api-python-client>=1.7.9
+google-auth-httplib2>=0.0.3
+google-auth-oauthlib>=0.4.0
 python-dateutil
 pytz