From e3c6ca43d3e3cad27714d07b3a9ec20141c9c65c Mon Sep 17 00:00:00 2001
From: Andrea Gottardo <andrea@tailscale.com>
Date: Thu, 21 Nov 2024 12:56:41 -0800
Subject: [PATCH] cli: present risk warning when setting up app connector on
 macOS (#14181)

---
 cmd/tailscale/cli/risks.go | 13 ++++++++++---
 cmd/tailscale/cli/set.go   |  7 +++++++
 cmd/tailscale/cli/up.go    |  6 ++++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/cmd/tailscale/cli/risks.go b/cmd/tailscale/cli/risks.go
index 4cfa50d58..acb50e723 100644
--- a/cmd/tailscale/cli/risks.go
+++ b/cmd/tailscale/cli/risks.go
@@ -17,11 +17,18 @@
 )
 
 var (
-	riskTypes   []string
-	riskLoseSSH = registerRiskType("lose-ssh")
-	riskAll     = registerRiskType("all")
+	riskTypes           []string
+	riskLoseSSH         = registerRiskType("lose-ssh")
+	riskMacAppConnector = registerRiskType("mac-app-connector")
+	riskAll             = registerRiskType("all")
 )
 
+const riskMacAppConnectorMessage = `
+You are trying to configure an app connector on macOS, which is not officially supported due to system limitations. This may result in performance and reliability issues. 
+
+Do not use a macOS app connector for any mission-critical purposes. For the best experience, Linux is the only recommended platform for app connectors.
+`
+
 func registerRiskType(riskType string) string {
 	riskTypes = append(riskTypes, riskType)
 	return riskType
diff --git a/cmd/tailscale/cli/set.go b/cmd/tailscale/cli/set.go
index 2e1251f04..e8e5f0c51 100644
--- a/cmd/tailscale/cli/set.go
+++ b/cmd/tailscale/cli/set.go
@@ -10,6 +10,7 @@
 	"fmt"
 	"net/netip"
 	"os/exec"
+	"runtime"
 	"strings"
 
 	"github.com/peterbourgon/ff/v3/ffcli"
@@ -203,6 +204,12 @@ func runSet(ctx context.Context, args []string) (retErr error) {
 		}
 	}
 
+	if runtime.GOOS == "darwin" && maskedPrefs.AppConnector.Advertise {
+		if err := presentRiskToUser(riskMacAppConnector, riskMacAppConnectorMessage, setArgs.acceptedRisks); err != nil {
+			return err
+		}
+	}
+
 	if maskedPrefs.RunSSHSet {
 		wantSSH, haveSSH := maskedPrefs.RunSSH, curPrefs.RunSSH
 		if err := presentSSHToggleRisk(wantSSH, haveSSH, setArgs.acceptedRisks); err != nil {
diff --git a/cmd/tailscale/cli/up.go b/cmd/tailscale/cli/up.go
index 782df407d..6c5c6f337 100644
--- a/cmd/tailscale/cli/up.go
+++ b/cmd/tailscale/cli/up.go
@@ -379,6 +379,12 @@ func updatePrefs(prefs, curPrefs *ipn.Prefs, env upCheckEnv) (simpleUp bool, jus
 		return false, nil, err
 	}
 
+	if runtime.GOOS == "darwin" && env.upArgs.advertiseConnector {
+		if err := presentRiskToUser(riskMacAppConnector, riskMacAppConnectorMessage, env.upArgs.acceptedRisks); err != nil {
+			return false, nil, err
+		}
+	}
+
 	if env.upArgs.forceReauth && isSSHOverTailscale() {
 		if err := presentRiskToUser(riskLoseSSH, `You are connected over Tailscale; this action will result in your SSH session disconnecting.`, env.upArgs.acceptedRisks); err != nil {
 			return false, nil, err