feat(cli): resolve a listener placement from the workspace listeners

2026-09-23 10:05:08 +02:00 · 2026-09-22 14:37:37 -04:00
parent 2ff8d6e950
commit 0a3fc2dd38
2 changed files with 227 additions and 0 deletions
@@ -178,6 +178,94 @@ class Listener:
        )


+@dataclass(frozen=True, slots=True)
+class Unplaced:
+    def source_config(self) -> dict[str, object]:
+        return {}
+
+
+@dataclass(frozen=True, slots=True)
+class OnListener:
+    listener_id: str
+    k8s_namespace: str
+
+    def source_config(self) -> dict[str, object]:
+        return {
+            "listener_id": self.listener_id,
+            "listener_config": {"k8s_namespace": self.k8s_namespace},
+        }
+
+
+Placement = Unplaced | OnListener
+
+
+@dataclass(frozen=True, slots=True)
+class RequestedPlacement:
+    listener_id: str | None = None
+    k8s_namespace: str | None = None
+
+    @property
+    def requested(self) -> bool:
+        return self.listener_id is not None or self.k8s_namespace is not None
+
+    def resolve(self, listeners: Sequence[Listener], *, required: bool) -> Placement:
+        if not listeners:
+            if self.requested:
+                raise click.UsageError(
+                    "This workspace has no listeners, so --listener-id and "
+                    "--k8s-namespace do not apply."
+                )
+            return Unplaced()
+        if not required and not self.requested:
+            return Unplaced()
+        listener = self._listener(listeners)
+        return OnListener(listener.id, self._namespace(listener))
+
+    def _listener(self, listeners: Sequence[Listener]) -> Listener:
+        if self.listener_id is None:
+            if len(listeners) == 1:
+                return listeners[0]
+            raise click.UsageError(
+                "This workspace has several listeners. Choose one with "
+                f"--listener-id:\n{_describe(listeners)}"
+            )
+        for listener in listeners:
+            if listener.id == self.listener_id:
+                return listener
+        raise click.UsageError(
+            f"Listener {self.listener_id} was not found in this workspace. "
+            f"Available listeners:\n{_describe(listeners)}"
+        )
+
+    def _namespace(self, listener: Listener) -> str:
+        if not listener.namespaces:
+            raise click.UsageError(
+                f"Listener {listener.id} serves no namespaces. Check its configuration."
+            )
+        if self.k8s_namespace is None:
+            if len(listener.namespaces) == 1:
+                return listener.namespaces[0]
+            raise click.UsageError(
+                f"Listener {listener.id} serves several namespaces. Choose one with "
+                f"--k8s-namespace: {', '.join(listener.namespaces)}"
+            )
+        if self.k8s_namespace not in listener.namespaces:
+            raise click.UsageError(
+                f"Listener {listener.id} does not serve namespace "
+                f"'{self.k8s_namespace}'. Choose one of: "
+                f"{', '.join(listener.namespaces)}"
+            )
+        return self.k8s_namespace
+
+
+def _describe(listeners: Sequence[Listener]) -> str:
+    return "\n".join(
+        f"  {listener.id}  cluster {listener.compute_id}  "
+        f"namespaces: {', '.join(listener.namespaces)}"
+        for listener in listeners
+    )
+
+
@dataclass(frozen=True, slots=True)
 class ExistingDeployment:
    id: str
@@ -17,7 +17,10 @@ from langgraph_cli.deploy import (
    DockerBuildCommand,
    Listener,
    ManagedRegistrySource,
+    OnListener,
    RemoteBuildSource,
+    RequestedPlacement,
+    Unplaced,
    _call_host_backend_with_optional_tenant,
    _create_host_backend_client,
    _docker_config_for_token,
@@ -927,3 +930,139 @@ class TestListener:
    )
    def test_from_resource_reads_the_control_plane_shape(self, resource, expected):
        assert Listener.from_resource(resource) == expected
+
+
+ONE_NAMESPACE = Listener("listener-1", "prod-cluster", ("agents",))
+TWO_NAMESPACES = Listener("listener-2", "multi-cluster", ("agents", "agents-staging"))
+NO_NAMESPACE = Listener("listener-3", "broken-cluster", ())
+
+
+class TestRequestedPlacement:
+    @pytest.mark.parametrize(
+        ("request_", "listeners", "required", "expected"),
+        [
+            pytest.param(
+                RequestedPlacement(), (), True, Unplaced(), id="no_listeners_no_request"
+            ),
+            pytest.param(
+                RequestedPlacement(),
+                (ONE_NAMESPACE,),
+                True,
+                OnListener("listener-1", "agents"),
+                id="cloud_uses_the_only_possible_answer",
+            ),
+            pytest.param(
+                RequestedPlacement(),
+                (ONE_NAMESPACE,),
+                False,
+                Unplaced(),
+                id="self_hosted_keeps_its_bundled_operator",
+            ),
+            pytest.param(
+                RequestedPlacement(listener_id="listener-1"),
+                (ONE_NAMESPACE,),
+                False,
+                OnListener("listener-1", "agents"),
+                id="self_hosted_places_when_asked",
+            ),
+            pytest.param(
+                RequestedPlacement(k8s_namespace="agents-staging"),
+                (TWO_NAMESPACES,),
+                True,
+                OnListener("listener-2", "agents-staging"),
+                id="namespace_alone_picks_the_only_listener",
+            ),
+            pytest.param(
+                RequestedPlacement(listener_id="listener-1"),
+                (ONE_NAMESPACE, TWO_NAMESPACES),
+                True,
+                OnListener("listener-1", "agents"),
+                id="listener_alone_picks_its_only_namespace",
+            ),
+            pytest.param(
+                RequestedPlacement(listener_id="listener-2", k8s_namespace="agents"),
+                (ONE_NAMESPACE, TWO_NAMESPACES),
+                True,
+                OnListener("listener-2", "agents"),
+                id="both_given",
+            ),
+        ],
+    )
+    def test_resolves_to_a_placement(self, request_, listeners, required, expected):
+        assert request_.resolve(listeners, required=required) == expected
+
+    @pytest.mark.parametrize(
+        ("request_", "listeners", "message"),
+        [
+            pytest.param(
+                RequestedPlacement(listener_id="listener-1"),
+                (),
+                "no listeners",
+                id="workspace_has_no_listeners",
+            ),
+            pytest.param(
+                RequestedPlacement(),
+                (ONE_NAMESPACE, TWO_NAMESPACES),
+                "--listener-id",
+                id="several_listeners_need_a_choice",
+            ),
+            pytest.param(
+                RequestedPlacement(k8s_namespace="agents"),
+                (ONE_NAMESPACE, TWO_NAMESPACES),
+                "--listener-id",
+                id="namespace_alone_is_ambiguous_with_several_listeners",
+            ),
+            pytest.param(
+                RequestedPlacement(listener_id="listener-9"),
+                (ONE_NAMESPACE,),
+                "was not found",
+                id="unknown_listener",
+            ),
+            pytest.param(
+                RequestedPlacement(),
+                (TWO_NAMESPACES,),
+                "--k8s-namespace",
+                id="several_namespaces_need_a_choice",
+            ),
+            pytest.param(
+                RequestedPlacement(listener_id="listener-2", k8s_namespace="nope"),
+                (TWO_NAMESPACES,),
+                "does not serve namespace",
+                id="unknown_namespace",
+            ),
+            pytest.param(
+                RequestedPlacement(listener_id="listener-3"),
+                (NO_NAMESPACE,),
+                "serves no namespaces",
+                id="listener_without_namespaces",
+            ),
+        ],
+    )
+    def test_refuses_and_names_the_choices(self, request_, listeners, message):
+        with pytest.raises(click.UsageError, match=message):
+            request_.resolve(listeners, required=True)
+
+    def test_the_error_lists_every_listener_with_its_cluster_and_namespaces(self):
+        with pytest.raises(click.UsageError) as error:
+            RequestedPlacement().resolve((ONE_NAMESPACE, TWO_NAMESPACES), required=True)
+
+        assert "listener-1" in error.value.message
+        assert "prod-cluster" in error.value.message
+        assert "agents-staging" in error.value.message
+
+    @pytest.mark.parametrize(
+        ("placement", "expected"),
+        [
+            pytest.param(Unplaced(), {}, id="unplaced_adds_nothing"),
+            pytest.param(
+                OnListener("listener-1", "agents"),
+                {
+                    "listener_id": "listener-1",
+                    "listener_config": {"k8s_namespace": "agents"},
+                },
+                id="placed_carries_listener_and_namespace",
+            ),
+        ],
+    )
+    def test_source_config_matches_the_control_plane_shape(self, placement, expected):
+        assert placement.source_config() == expected