Merge pull request #826 from manics/callable-env

Don't attempt to expand callable environment variables

kubespawner/spawner.py

@@ -1841,6 +1841,17 @@ def _expand_user_properties(self, template):
             rendered = rendered.rstrip("-")
         return rendered
 
+    def _expand_env(self, env):
+        # environment expansion requires special handling because the parent class
+        # may have also modified it, e.g. by evaluating a callable
+        expanded_env = {}
+        for k, v in env.items():
+            if isinstance(v, (list, dict, str)):
+                expanded_env[k] = self._expand_all(v)
+            # else do nothing- this will be merged with the parent env
+            # by the caller so by omitting the key we keep the parent value
+        return expanded_env
+
     def _expand_all(self, src):
         if isinstance(src, list):
             return [self._expand_all(i) for i in src]
@@ -2166,7 +2177,7 @@ def get_env(self):
         # Explicitly expand *and* set all the admin specified variables only.
         # This allows JSON-like strings set by JupyterHub itself to not be
         # expanded. https://github.com/jupyterhub/kubespawner/issues/743
-        env.update(self._expand_all(self.environment))
+        env.update(self._expand_env(self.environment))
 
         return env
 

tests/test_spawner.py

@@ -1342,6 +1342,22 @@ async def test_pod_name_no_named_servers():
     assert spawner.pod_name == "jupyter-user"
 
 
+async def test_spawner_env():
+    c = Config()
+    c.Spawner.environment = {
+        "STATIC": "static",
+        "EXPANDED": "{username} (expanded)",
+        "ESCAPED": "{{username}}",
+        "CALLABLE": lambda spawner: spawner.user.name + " (callable)",
+    }
+    spawner = KubeSpawner(config=c, _mock=True)
+    env = spawner.get_env()
+    assert env["STATIC"] == "static"
+    assert env["EXPANDED"] == "mock-5fname (expanded)"
+    assert env["ESCAPED"] == "{username}"
+    assert env["CALLABLE"] == "mock_name (callable)"
+
+
 async def test_jupyterhub_supplied_env():
     cookie_options = {"samesite": "None", "secure": True}
     c = Config()