Add token caching

propedal-planner/calendar_interface.py

@@ -13,7 +13,8 @@ except ImportError:
      from backports.zoneinfo import ZoneInfo
 
 WEEKDAYS= {0:"Mo", 1:"Di", 2:"Mi", 3:"Do", 4: "Fr", 5:"Sa", 6: "So"}
-result = None
+token = None
+cache = msal.SerializableTokenCache()
 
 # Optional logging
 
@@ -21,36 +22,38 @@ result = None
 
 # Create a preferably long-lived app instance which maintains a token cache.
 app = msal.ConfidentialClientApplication(
-    MsalConfig.CLIENT_ID, authority=MsalConfig.AUTHORITY,
+    MsalConfig.CLIENT_ID, 
+    authority=MsalConfig.AUTHORITY,
     client_credential=MsalConfig.SECRET,
-    # token_cache=...  # Default cache is in memory only.
+    token_cache=cache
+        # Default cache is in memory only.
                     # You can learn how to use SerializableTokenCache from
                     # https:#msal-python.readthedocs.io/en/latest/#msal.SerializableTokenCache
     )
 
 def get_access_token():
-    global app, result
+    global app, token
 
     # The pattern to acquire a token looks like this.
 
     # Firstly, looks up a token from cache
     # Since we are looking for token for the current app, NOT for an end user,
     # notice we give account parameter as None.
-    result = app.acquire_token_silent(MsalConfig.SCOPE, account=None)
+    token = app.acquire_token_silent(MsalConfig.SCOPE, account=None)
 
-    if result is None:
+    if token is None:
         logging.info("No suitable token exists in cache. Let's get a new one from AAD.")
-        result= app.acquire_token_for_client(scopes=MsalConfig.SCOPE)
+        token= app.acquire_token_for_client(scopes=MsalConfig.SCOPE)
     else:
         logging.info("Token was found in cache.")
 
-    if not "access_token" in result: # a final check
-        logging.error(result.get("error"))
-        logging.error(result.get("error_description"))
-        logging.error(result.get("correlation_id"))  # You may need this when reporting a bug
+    if not "access_token" in token: # a final check
+        logging.error(token.get("error"))
+        logging.error(token.get("error_description"))
+        logging.error(token.get("correlation_id"))  # You may need this when reporting a bug
         raise AssertionError("Was not able to get an access token. Check msal auth.")
 
-    return result
+    return token
 
 def execute_get_request(token: dict, endpoint:str):
     return requests.get(  # Use token to call downstream service