chore: add warning to Client.login

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - `wait_completion` param on `get_performances`, `list_task_output_assets` and `get_task_output_asset` to block execution until execution is over ([#368](https://github.com/Substra/substra/pull/368))
 - `list_task_output_assets` and `get_task_output_asset` wait that the compute task is over before getting assets ([#369](https://github.com/Substra/substra/pull/369))
+- warning and help message when logging in with username/password rather than token ([#378](https://github.com/Substra/substra/pull/378))
 
 ## [0.46.0](https://github.com/Substra/substra/releases/tag/0.46.0) - 2023-07-25
 

substra/sdk/backends/remote/rest_client.py

@@ -1,6 +1,9 @@
 import json
 import logging
 import time
+from datetime import datetime
+from datetime import timedelta
+from datetime import timezone
 from typing import Dict
 from typing import List
 from typing import Union
@@ -15,6 +18,22 @@
 logger = logging.getLogger(__name__)
 
 
+def _warn_of_session_expiration(expiration: str) -> None:
+    log_level = logging.INFO
+    try:
+        duration = datetime.fromisoformat(expiration) - datetime.now(timezone.utc)
+        if duration.days:
+            duration_msg = f"{duration.days} days"
+        else:
+            duration_msg = f"{duration.seconds//3600} hours"
+        expires_at = f"in {duration_msg} ({expiration})"
+        if duration < timedelta(hours=4):
+            log_level = logging.WARNING
+    except ValueError:  # Python 3.11 parses more formats than previous versions
+        expires_at = expiration
+    logger.log(log_level, f"Your session will expire {expires_at}")
+
+
 class Client:
     """REST Client to communicate with Substra server."""
 
@@ -60,17 +79,31 @@ def login(self, username, password):
             if e.response.status_code in (400, 401):
                 raise exceptions.BadLoginException.from_request_exception(e)
 
+            if (
+                e.response.status_code == 403
+                and getattr(e.response, "substra_identifier", None) == "implicit_login_disabled"
+            ):
+                raise exceptions.UsernamePasswordLoginDisabledException.from_request_exception(e)
+
             raise exceptions.HTTPError.from_request_exception(e)
 
         try:
-            token = r.json()["token"]
+            rj = r.json()
+            token = rj["token"]
         except json.decoder.JSONDecodeError:
             # sometimes requests seem to be fine, but the json is not being found
             # this might be if the url seems to be correct (in the syntax)
             # but it's not the right one
             raise exceptions.BadConfiguration(
                 "Unable to get token from json response. " f"Make sure that given url: {self._base_url} is correct"
             )
+
+        logger.info(
+            "Logging in with username/password is discouraged; "
+            "you should generate a token on the web UI instead: "
+            "https://docs.substra.org/en/stable/documentation/api_tokens_generation.html"
+        )
+        _warn_of_session_expiration(rj["expires_at"])
         self._headers["Authorization"] = f"Token {token}"
 
         return token

substra/sdk/exceptions.py

@@ -142,6 +142,24 @@ class BadLoginException(RequestException):
     pass
 
 
+class UsernamePasswordLoginDisabledException(RequestException):
+    """The server disabled the endpoint, preventing the use of Client.login"""
+
+    @classmethod
+    def from_request_exception(cls, request_exception):
+        base = super().from_request_exception(request_exception)
+        return cls(
+            base.msg
+            + (
+                "\n\nAuthenticating with username/password is disabled.\n"
+                "Log onto the frontend for your instance and generate a token there, "
+                'then use it in the Client(token="...") constructor: '
+                "https://docs.substra.org/en/stable/documentation/api_tokens_generation.html"
+            ),
+            base.status_code,
+        )
+
+
 class ConfigurationInfoError(SDKException):
     """ConfigurationInfoError"""