ipn/ipnlocal: reset auto-updates if unsupported on profile load (#11838)

Prior to
1613b18f82 (diff-314ba0d799f70c8998940903efb541e511f352b39a9eeeae8d475c921d66c2ac),
nodes could set AutoUpdate.Apply=true on unsupported platforms via
`EditPrefs`. Specifically, this affects tailnets where default
auto-updates are on.

Fix up those invalid prefs on profile reload, as a migration.

Updates #11544

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>

ipn/ipnlocal/profiles.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 	"time"
 
+	"tailscale.com/clientupdate"
 	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/types/logger"
@@ -366,6 +367,16 @@ func (pm *profileManager) loadSavedPrefs(key ipn.StateKey) (ipn.PrefsView, error
 		ipn.IsLoginServerSynonym(savedPrefs.ControlURL) {
 		savedPrefs.ControlURL = ""
 	}
+	// Before
+	// https://github.com/tailscale/tailscale/pull/11814/commits/1613b18f8280c2bce786980532d012c9f0454fa2#diff-314ba0d799f70c8998940903efb541e511f352b39a9eeeae8d475c921d66c2ac
+	// prefs could set AutoUpdate.Apply=true via EditPrefs or tailnet
+	// auto-update defaults. After that change, such value is "invalid" and
+	// cause any EditPrefs calls to fail (other than disabling autp-updates).
+	//
+	// Reset AutoUpdate.Apply if we detect such invalid prefs.
+	if savedPrefs.AutoUpdate.Apply.EqualBool(true) && !clientupdate.CanAutoUpdate() {
+		savedPrefs.AutoUpdate.Apply.Clear()
+	}
 	return savedPrefs.View(), nil
 }
 

ipn/ipnlocal/profiles_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
+	"tailscale.com/clientupdate"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/store/mem"
 	"tailscale.com/tailcfg"
@@ -339,6 +340,7 @@ func TestProfileManagement(t *testing.T) {
 			t.Fatalf("Profiles = %v; want %v", profiles, wantProfiles)
 		}
 		p := pm.CurrentPrefs()
+		t.Logf("\tCurrentPrefs = %s", p.Pretty())
 		if !p.Valid() {
 			t.Fatalf("CurrentPrefs = %v; want valid", p)
 		}
@@ -458,6 +460,27 @@ func TestProfileManagement(t *testing.T) {
 	delete(wantProfiles, "tagged-node.2.ts.net")
 	wantCurProfile = "user@2.example.com"
 	checkProfiles(t)
+
+	if !clientupdate.CanAutoUpdate() {
+		t.Logf("Save an invalid AutoUpdate pref value")
+		prefs := pm.CurrentPrefs().AsStruct()
+		prefs.AutoUpdate.Apply.Set(true)
+		if err := pm.SetPrefs(prefs.View(), ipn.NetworkProfile{}); err != nil {
+			t.Fatal(err)
+		}
+		if !pm.CurrentPrefs().AutoUpdate().Apply.EqualBool(true) {
+			t.Fatal("SetPrefs failed to save auto-update setting")
+		}
+		// Re-load profiles to trigger migration for invalid auto-update value.
+		pm, err = newProfileManagerWithGOOS(store, logger.Discard, "linux")
+		if err != nil {
+			t.Fatal(err)
+		}
+		checkProfiles(t)
+		if pm.CurrentPrefs().AutoUpdate().Apply.EqualBool(true) {
+			t.Fatal("invalid auto-update setting persisted after reload")
+		}
+	}
 }
 
 // TestProfileManagementWindows tests going into and out of Unattended mode on