Auto update IDE settings for serverless ssh mode (#4559)

## Changes
In serverless ssh mode (ssh connect command without cluster flag and
with the ide flag set), we need to set up the desired server ports (or
socket connection mode) for the connection to go through (as the
majority of the localhost ports on the remote side are blocked by
iptable rules). Plus the platform (always linux), and extensions (python
and jupyter), to make the initial experience smoother.

This is done by checking the IDE settings file and updating it if
necessary, prompting the user for confirmation before doing so.

If the settings file is not found (fresh IDE install), we create one
with the recommended configuration. If there are any other issues during
the update process, we log the error and print the manual instructions
for the user, proceeding with the connection anyway.


## Tests
New unit tests, plus manual tests on all platforms (WIP)

<!-- If your PR needs to be included in the release notes for next
release,
add a separate entry in NEXT_CHANGELOG.md as part of your PR. -->

Author: ilia-db

experimental/ssh/cmd/connect.go

@@ -35,6 +35,7 @@ the SSH server and handling the connection proxy.
 	var autoStartCluster bool
 	var userKnownHostsFile string
 	var liteswap string
+	var skipSettingsCheck bool
 
 	cmd.Flags().StringVar(&clusterID, "cluster", "", "Databricks cluster ID (for dedicated clusters)")
 	cmd.Flags().DurationVar(&shutdownDelay, "shutdown-delay", defaultShutdownDelay, "Delay before shutting down the server after the last client disconnects")
@@ -64,6 +65,9 @@ the SSH server and handling the connection proxy.
 	cmd.Flags().StringVar(&liteswap, "liteswap", "", "Liteswap header value for traffic routing (dev/test only)")
 	cmd.Flags().MarkHidden("liteswap")
 
+	cmd.Flags().BoolVar(&skipSettingsCheck, "skip-settings-check", false, "Skip checking and updating IDE settings")
+	cmd.Flags().MarkHidden("skip-settings-check")
+
 	cmd.PreRunE = func(cmd *cobra.Command, args []string) error {
 		// CLI in the proxy mode is executed by the ssh client and can't prompt for input
 		if proxyMode {
@@ -113,6 +117,7 @@ the SSH server and handling the connection proxy.
 			ClientPrivateKeyName: clientPrivateKeyName,
 			UserKnownHostsFile:   userKnownHostsFile,
 			Liteswap:             liteswap,
+			SkipSettingsCheck:    skipSettingsCheck,
 			AdditionalArgs:       args,
 		}
 		return client.Run(ctx, wsClient, opts)

experimental/ssh/internal/client/client.go

@@ -20,6 +20,7 @@ import (
 	"github.com/databricks/cli/experimental/ssh/internal/keys"
 	"github.com/databricks/cli/experimental/ssh/internal/proxy"
 	"github.com/databricks/cli/experimental/ssh/internal/sshconfig"
+	"github.com/databricks/cli/experimental/ssh/internal/vscode"
 	sshWorkspace "github.com/databricks/cli/experimental/ssh/internal/workspace"
 	"github.com/databricks/cli/internal/build"
 	"github.com/databricks/cli/libs/cmdio"
@@ -92,6 +93,8 @@ type ClientOptions struct {
 	UserKnownHostsFile string
 	// Liteswap header value for traffic routing (dev/test only).
 	Liteswap string
+	// If true, skip checking and updating IDE settings.
+	SkipSettingsCheck bool
 }
 
 func (o *ClientOptions) IsServerlessMode() bool {
@@ -206,6 +209,26 @@ func Run(ctx context.Context, client *databricks.WorkspaceClient, opts ClientOpt
 	cmdio.LogString(ctx, "Using SSH key: "+keyPath)
 	cmdio.LogString(ctx, fmt.Sprintf("Secrets scope: %s, key name: %s", secretScopeName, opts.ClientPublicKeyName))
 
+	// Check and update IDE settings for serverless mode, where we must set up
+	// desired server ports (or socket connection mode) for the connection to go through
+	// (as the majority of the localhost ports on the remote side are blocked by iptable rules).
+	// Plus the platform (always linux), and extensions (python and jupyter), to make the initial experience smoother.
+	if opts.IDE != "" && opts.IsServerlessMode() && !opts.ProxyMode && !opts.SkipSettingsCheck && cmdio.IsPromptSupported(ctx) {
+		err = vscode.CheckAndUpdateSettings(ctx, opts.IDE, opts.ConnectionName)
+		if err != nil {
+			cmdio.LogString(ctx, fmt.Sprintf("Failed to update IDE settings: %v", err))
+			cmdio.LogString(ctx, vscode.GetManualInstructions(opts.IDE, opts.ConnectionName))
+			cmdio.LogString(ctx, "Use --skip-settings-check to bypass IDE settings verification.")
+			shouldProceed, promptErr := cmdio.AskYesOrNo(ctx, "Do you want to proceed with the connection?")
+			if promptErr != nil {
+				return fmt.Errorf("failed to prompt user: %w", promptErr)
+			}
+			if !shouldProceed {
+				return errors.New("aborted: IDE settings need to be updated manually, user declined to proceed")
+			}
+		}
+	}
+
 	var userName string
 	var serverPort int
 	var clusterID string