From ece9febe1dde42c6092caeedb9117be0d7933d6f Mon Sep 17 00:00:00 2001 From: Nino Kodabande Date: Wed, 21 Aug 2024 12:32:32 -0700 Subject: [PATCH] Add a link to the main document in README Signed-off-by: Nino Kodabande --- src/go/guestagent/README.md | 48 +------------------------------------ 1 file changed, 1 insertion(+), 47 deletions(-) diff --git a/src/go/guestagent/README.md b/src/go/guestagent/README.md index b584deab6f8..a6af71ffb54 100644 --- a/src/go/guestagent/README.md +++ b/src/go/guestagent/README.md @@ -1,47 +1 @@ -# Rancher Desktop Agent - -The Rancher Desktop guest agent runs in Rancher Desktop VMs providing helper -services. It currently has the following functionality: - -## Port forwarding with privileged helper: - -When the Rancher Desktop Privileged Service is enabled on the host Windows machine via an admin installation of Rancher Desktop, the guest agent watches for port binding events from corresponding backend's API and emits them to the host via a virtual tunnel. - -```mermaid -flowchart LR; - subgraph Host["HOST"] - rd{"Rancher Desktop"} - ps(("Privileged Service")) - rd <-.-> ps - end - subgraph VM["WSL VM"] - rdagent(("Guest Agent")) - api(("moby/containerd \n events API")) - rdagent <-.-> api - end - ps <---> |Vtunnel| rdagent -``` - -### moby port forwarding (WSL) - -Rancher Desktop Guest Agent subscribes to [docker event API](https://docs.docker.com/engine/api/v1.41/#tag/System/operation/SystemEvents) to monitor the newly created published ports. It will then forwards the newly published ports over a `AF_VSOCK` tunnel (Rancher Desktop's `vtunnel`) to [Rancher Desktop Privileged Service](https://github.com/rancher-sandbox/rancher-desktop/tree/main/src/go/privileged-service) that runs on the host machine. - -### containerd port forwarding (WSL) - -When using the containerd backend, the behaviour of Rancher Desktop Guest Agent is very similar to when the moby backend is enabled. It monitors containerd's event API for the newly created published ports. It will then forwards the newly published ports over a `AF_VSOCK` tunnel (Rancher Desktop's `vtunnel`) to Rancher Desktop Privileged Service that runs on the host machine. - -## When Privileged Service is disabled: - -When the Rancher Desktop Privileged Service is not enabled on the host Windows machine via a non admin installation of Rancher Desktop, the guest agent watches the iptables for newly added rules. - -### containerd port forwarding (WSL) when no privileged service is enabled - -When Rancher Desktop Privileged Service is not enabled (non-admin installation), Rancher Desktop Agent falls back to the following behaviour. -In Windows Subsystem for Linux, WSL automatically forwards ports opened on `127.0.0.1` or `0.0.0.0` by opening the corresponding port on `127.0.0.1` on the host (running Windows). However, `containerd` (as configured by `nerdctl`) just sets up `iptables` rules rather than actually listening, meaning this isn't caught by the normal mechanisms. Rancher Desktop Agent therefore creates the listeners so that they get picked up and forwarded automatically. Note that the listeners will never receive any traffic, as the `iptables` rules are in place to forward the traffic before it reaches the application. This is not necessary -for Lima, as that already does the `iptables` scanning (the core of the code has been lifted from Lima). - -## Kubernetes NodePort forwarding - -In newer versions of Kubernetes†, `kubelet` no longer creates a listener for NodePort services. We therefore need to create those listeners manually, so that port forward works correctly as in the container port forwarding above. - -† 1.21.12+, 1.22.10+, 1.23.7+, 1.24+ +[Rancher Desktop Guest Agent](/docs/networking/windows/rancher-desktop-guest-agent.md) \ No newline at end of file