feat: add Client.logout and context manager

CHANGELOG.md

@@ -12,10 +12,13 @@ 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))
+- new `Client.logout` function, mirroring `Client.login` ([#381](https://github.com/Substra/substra/pull/381))
+- `Client` can now be the expression in a `with` statement ([#381](https://github.com/Substra/substra/pull/381))
 
 ### Changed
 
 - change how API responses are parsed to match server changes ([#379](https://github.com/Substra/substra/pull/379))
+- `Client` will now terminate the sessions it starts when given username & password ([#381](https://github.com/Substra/substra/pull/381))
 
 ### Fixed
 

substra/sdk/backends/remote/backend.py

@@ -42,6 +42,9 @@ def backend_mode(self) -> schemas.BackendType:
     def login(self, username, password):
         return self._client.login(username, password)
 
+    def logout(self):
+        return self._client.logout()
+
     def get(self, asset_type, key):
         """Get an asset by key."""
         asset = self._client.get(asset_type.to_server(), key)

substra/sdk/backends/remote/rest_client.py

@@ -52,6 +52,7 @@ def __init__(self, url, insecure, token):
         if not url:
             raise exceptions.SDKException("url required to connect to the Substra server")
         self._base_url = url[:-1] if url.endswith("/") else url
+        self._token_id = None  # filled in by self.login
 
     def login(self, username, password):
         # we do not use self._headers in order to avoid existing tokens to be sent alongside the
@@ -90,6 +91,7 @@ def login(self, username, password):
         try:
             rj = r.json()
             token = rj["token"]
+            self._token_id = rj["id"]
         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)
@@ -108,6 +110,23 @@ def login(self, username, password):
 
         return token
 
+    def logout(self) -> None:
+        if not self._token_id:
+            return
+        try:
+            r = requests.delete(
+                f"{self._base_url}/active-api-tokens/", params={"id": self._token_id}, headers=self._headers
+            )
+            r.raise_for_status()
+            self._token_id = None
+            logger.info("Successfully logged out")
+        except requests.exceptions.ConnectionError as e:
+            raise exceptions.ConnectionError.from_request_exception(e)
+        except requests.exceptions.Timeout as e:
+            raise exceptions.Timeout.from_request_exception(e)
+        except requests.exceptions.HTTPError as e:
+            raise exceptions.HTTPError.from_request_exception(e)
+
     # TODO: '__request' is too complex, consider refactoring
     def __request(self, request_name, url, **request_kwargs):  # noqa: C901
         """Base request helper."""

substra/sdk/client.py

@@ -311,6 +311,15 @@ def __init__(
             )
             self._token = self.login(config_dict["username"].value, config_dict["password"].value)
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.logout()
+
+    def __del__(self):
+        self.logout()
+
     def _get_backend(self, backend_type: schemas.BackendType):
         # Three possibilities:
         # - remote: get a remote backend
@@ -369,6 +378,17 @@ def login(self, username, password):
         self._token = self._backend.login(username, password)
         return self._token
 
+    @logit
+    def logout(self) -> None:
+        """
+        Log out from a remote server, if Client.login was used
+        (otherwise, nothing happens)
+        """
+        if not self._backend:
+            raise exceptions.SDKException("No backend found")
+        if hasattr(self._backend, "logout"):
+            self._backend.logout()
+
     @staticmethod
     def _get_spec(asset_type, data):
         if isinstance(data, asset_type):