support for bind propagation (#526)

* added support for propagation * added homedir propagation modifications * only set bind propagation if provided simplifies support, removed need for latest docker-py --------- Co-authored-by: Janne Jakob Fleischer <[email protected]>
jupyterhub · Feb 12, 2025 · e7d609b · e7d609b
1 parent 1a65caa
commit e7d609b
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Showing 3 changed files with 33 additions and 5 deletions.
diff --git a/dockerspawner/dockerspawner.py b/dockerspawner/dockerspawner.py
@@ -1014,7 +1014,9 @@ async def poll(self):
 
         container_state = container["State"]
         self.log.debug(
-            "Container %s status: %s", self.container_id[:7], json.dumps(container_state, ensure_ascii=False)
+            "Container %s status: %s",
+            self.container_id[:7],
+            json.dumps(container_state, ensure_ascii=False),
         )
 
         if container_state["Running"]:
@@ -1453,11 +1455,16 @@ def _fmt(v):
 
         for k, v in volumes.items():
             m = mode
+            propagation = None
             if isinstance(v, dict):
                 if "mode" in v:
                     m = v["mode"]
+                if "propagation" in v:
+                    propagation = v["propagation"]
                 v = v["bind"]
-            binds[_fmt(k)] = {"bind": _fmt(v), "mode": m}
+            binds[_fmt(k)] = bind = {"bind": _fmt(v), "mode": m}
+            if propagation:
+                bind["propagation"] = propagation
         return binds
 
     def _render_templates(self, obj, ns=None):

diff --git a/dockerspawner/systemuserspawner.py b/dockerspawner/systemuserspawner.py
@@ -34,6 +34,22 @@ class SystemUserSpawner(DockerSpawner):
         ),
     )
 
+    homedir_bind_propagation = Unicode(
+        "",
+        config=True,
+        help=dedent(
+            """
+            Mode for bind mount propagation for home directory.
+
+            Requires docker-py 7.0.
+
+            See https://docs.docker.com/engine/storage/bind-mounts/#configure-bind-propagation
+
+            .. versionadded:: 13.1
+            """
+        ),
+    )
+
     run_as_root = Bool(
         False,
         config=True,
@@ -129,7 +145,12 @@ def volume_binds(self):
             }
         """
         volumes = super().volume_binds
-        volumes[self.host_homedir] = {'bind': self.homedir, 'ro': False}
+        volumes[self.host_homedir] = home_volume = {
+            'bind': self.homedir,
+            'ro': False,
+        }
+        if self.homedir_bind_propagation:
+            home_volume["propagation"] = self.homedir_bind_propagation
         return volumes
 
     def get_env(self):

diff --git a/tests/volumes_test.py b/tests/volumes_test.py
@@ -12,10 +12,10 @@ def test_binds(monkeypatch):
 
     d = DockerSpawner()
     d.user = types.SimpleNamespace(name="xyz")
-    d.volumes = {"a": "b", "c": {"bind": "d", "mode": "Z"}}
+    d.volumes = {"a": "b", "c": {"bind": "d", "mode": "Z", "propagation": "rprivate"}}
     assert d.volume_binds == {
         "a": {"bind": "b", "mode": "rw"},
-        "c": {"bind": "d", "mode": "Z"},
+        "c": {"bind": "d", "mode": "Z", "propagation": 'rprivate'},
     }
     d.volumes = {"a": "b", "c": "d", "e": "f"}
     assert d.volume_mount_points == ["b", "d", "f"]