[Dashboard] A get_dashboard_url() API

[wingkitlee0]

Description

Currently, to get the dashboard URL, one needs to do a ctx = ray.init(...); print(ctx.dashboard_url). This is not very convenient in interactive / notebook environment (users either need to remember to assign a variable in the beginning or rerun ray.init).

We can add a get_dashboard_url() method to RayContext:

def get_dashboard_url(self) -> str:
    return self.worker.node.webui_url

so that users can get it by using the runtime context ctx = ray.get_runtime_context().

However I am not sure the use of other lesser known API, e.g., get_address_for_submission_client(None)

Use case

In some platforms, e.g., databricks / sagemaker, there are custom URLs used for port forwarding. Having an API to grab the dashboard URL will be useful

[chuang0221]

This would be quite useful. I often forget to save the context after initialization and currently have to either rerun ray.init() or access ray._private.worker._global_node.webui_url to get the dashboard URL. I’d be happy to work on this if no one else is working on it.