Updated docs for interface and mux

Signed-off-by: Thomas Kosiewski <thomas.kosiewski@loft.sh>

Author: Thomas Kosiewski

coordinator.go

@@ -9,22 +9,52 @@ import (
 	"tailscale.com/types/key"
 )
 
+// TailscaleCoordinator is the interface that wraps the tailscale coordinator
+// methods.
 type TailscaleCoordinator interface {
+	// ControlKey returns the control key for coordinator.
 	ControlKey() key.MachinePrivate
+	// LegacyControlKey returns the legacy control key for coordinator.
 	LegacyControlKey() key.MachinePrivate
 
+	// RegisterMachine is responsible for registering the machine with the
+	// coordinator. It returns the registration response from the coordinator
+	// and an error if any.
 	RegisterMachine(req tailcfg.RegisterRequest, peerPublicKey key.MachinePublic) (tailcfg.RegisterResponse, error)
 
+	// DerpMap returns the DERP map from the coordinator.
 	DerpMap() (tailcfg.DERPMap, error)
 
+	// KeepAliveInterval is the keep alive interval of the coordinator.
 	KeepAliveInterval() time.Duration
+	// PollNetMap handles the netmap polling request from a tailscale client. It
+	// returns a channel of netmap responses and a channel of errors.
+	//
+	// - If the request is a streaming one, the channels are not to be closed
+	// and new responses will be sent on the channels.
+	//
+	// - If the request is a non-streaming one, the channels are to be closed
+	// after the first response is sent.
+	//
+	// - If the request gets closed or cancelled by the tailscale client, the
+	// context will be cancelled and the channels shall not be used anymore.
 	PollNetMap(ctx context.Context, req tailcfg.MapRequest, peerPublicKey key.MachinePublic) (chan tailcfg.MapResponse, chan error)
 
+	// SetDNS handles the DNS setting request from a tailscale client.
 	SetDNS(req tailcfg.SetDNSRequest, peerPublicKey key.MachinePublic) (tailcfg.SetDNSResponse, error)
 
+	// HealthChange handles the health change request from a tailscale client.
 	HealthChange(req tailcfg.HealthChangeRequest)
 
+	// IDToken handles the ID token request from a tailscale client.
 	IDToken(req tailcfg.TokenRequest, peerPublicKey key.MachinePublic) (tailcfg.TokenResponse, error)
 
+	// SSHAction handles the SSH action request from a tailscale client.
+	//
+	// It returns the SSH action response and an error if any. Additionally, the
+	// entire request is provided to the implementation as the request may
+	// contain additional information that is not known to the library.
+	//
+	// This method handles all noise requests to the `/ssh/action/*` pattern.
 	SSHAction(r *http.Request, peerPublicKey key.MachinePublic) (tailcfg.SSHAction, error)
 }

handlers/mux.go

@@ -7,6 +7,8 @@ import (
 	"github.com/loft-sh/tunnel"
 )
 
+// CoordinatorHandler returns a http.Handler that handles all requests to the
+// coordinator, including the noise requests.
 func CoordinatorHandler(coordinator tunnel.TailscaleCoordinator) http.Handler {
 	mux := chi.NewMux()