[KubeRay] Add instructions to run distributed Ray Debugger in KubeRay

doc/source/ray-observability/ray-distributed-debugger.rst

@@ -35,7 +35,44 @@ Create a new virtual environment and install dependencies.
 Start a Ray cluster
 ~~~~~~~~~~~~~~~~~~~
 
-Run `ray start --head` to start a Ray cluster.
+.. tab-set::
+
+  .. tab-item:: Local
+
+    Run `ray start --head` to start a local Ray cluster.
+
+  .. tab-item:: KubeRay
+
+    Follow the instructions in :doc:`the RayCluster quickstart <../cluster/kubernetes/getting-started/raycluster-quick-start>` to set up a cluster.
+    You need to connect VS Code to the cluster. For example, add the following to the `ray-head` container and make sure `sshd` is running in the `ray-head` container.
+
+    .. code-block:: yaml
+
+        ports:
+        - containerPort: 22
+          name: ssd
+
+
+
+    .. note::
+
+        How to run `sshd` in the `ray-head` container depends on your setup. For example you can use `supervisord`.
+        A simple way to run `sshd` interactively for testing is by logging into the head node pod and running:
+
+        .. code-block:: bash
+
+            sudo apt-get install openssh-server
+            sudo mkdir -p /run/sshd
+            sudo /usr/sbin/sshd -D
+
+    You can then connect to the cluster via SSH by running:
+
+    .. code-block:: bash
+
+        kubectl port-forward service/raycluster-sample-head-svc 2222:22
+
+    After checking that `ssh -p 2222 ray@localhost` works, set up VS Code as described in the
+    `VS Code SSH documentation <https://code.visualstudio.com/docs/remote/ssh>`_.
 
 
 Register the cluster