Revert the default port forwarder to SSH

The GRPC port forwarder is still too unstable (issue 2859, etc.)

Signed-off-by: Akihiro Suda <[email protected]>

Author: AkihiroSuda

pkg/hostagent/hostagent.go

@@ -654,8 +654,16 @@ func (a *HostAgent) processGuestAgentEvents(ctx context.Context, client *guestag
 		for _, f := range ev.Errors {
 			logrus.Warnf("received error from the guest: %q", f)
 		}
-		env, _ := strconv.ParseBool(os.Getenv("LIMA_SSH_PORT_FORWARDER"))
-		if env {
+		// useSSHFwd was false by default in v1.0, but reverted to true by default in v1.0.1
+		// due to stability issues
+		useSSHFwd := true
+		if envVar := os.Getenv("LIMA_SSH_PORT_FORWARDER"); envVar != "" {
+			useSSHFwd, err = strconv.ParseBool(os.Getenv("LIMA_SSH_PORT_FORWARDER"))
+			if err != nil {
+				return fmt.Errorf("invalid LIMA_SSH_PORT_FORWARDER value %q: %w", envVar, err)
+			}
+		}
+		if useSSHFwd {
 			a.portForwarder.OnEvent(ctx, ev)
 		} else {
 			a.grpcPortForwarder.OnEvent(ctx, client, ev)

website/content/en/docs/config/Port/_index.md

@@ -7,11 +7,19 @@ Lima supports automatic port-forwarding of localhost ports from guest to host.
 
 ## Port forwarding types
 
+Lima supports two port forwarder: SSH and GRPC.
+
+The default port forwarder is SSH.
+
+The default was once changed to GRPC in Lima v1.0, but it was reverted to SSH in v1.0.1 due to stability reasons.
+
+In future, it is expected that GRPC will take over the default position again.
+
 ### Using SSH
 
-SSH based port forwarding is the default and current model that is supported in Lima prior to v1.0.
+SSH based port forwarding is the default and current model that is supported in Lima.
 
-To use SSH forwarding use the below command
+To explicitly use SSH forwarding use the below command
 
 ```bash
 LIMA_SSH_PORT_FORWARDER=true limactl start
@@ -22,18 +30,18 @@ LIMA_SSH_PORT_FORWARDER=true limactl start
 - Doesn't support UDP based port forwarding
 - Spans child process on host for running SSH master.
 
-### Using GRPC (Default since Lima v1.0)
+### Using GRPC
 
 | ⚡ Requirement | Lima >= 1.0 |
 |---------------|-------------|
 
 In this model, lima uses existing GRPC communication (Host <-> Guest) to tunnel port forwarding requests.
 For each port forwarding request, a GRPC tunnel is created and this will be used for transmitting data
 
-To disable this feature and use SSH forwarding use the following environment variable
+To enable this feature, set `LIMA_SSH_PORT_FORWARDER` to `false`:
 
 ```bash
-LIMA_SSH_PORT_FORWARDER=true limactl start
+LIMA_SSH_PORT_FORWARDER=false limactl start
 ```
 
 #### Advantages