health: send ImpactsConnectivity value over LocalAPI (#12700)

Updates tailscale/tailscale#4136

We should make sure to send the value of ImpactsConnectivity over to the clients using LocalAPI as they need it to display alerts in the GUI properly.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>

health/state.go

@@ -30,6 +30,7 @@ type UnhealthyState struct {
 	BrokenSince         *time.Time     `json:",omitempty"`
 	Args                Args           `json:",omitempty"`
 	DependsOn           []WarnableCode `json:",omitempty"`
+	ImpactsConnectivity bool           `json:",omitempty"`
 }
 
 // unhealthyState returns a unhealthyState of the Warnable given its current warningState.
@@ -61,6 +62,7 @@ func (w *Warnable) unhealthyState(ws *warningState) *UnhealthyState {
 		BrokenSince:         &ws.BrokenSince,
 		Args:                ws.Args,
 		DependsOn:           dependsOnWarnableCodes,
+		ImpactsConnectivity: w.ImpactsConnectivity,
 	}
 }
 

health/warnings.go

@@ -94,13 +94,13 @@ var LoginStateWarnable = Register(&Warnable{
 	},
 })
 
-// notInMapPollWarnable is a Warnable that warns the user that they cannot connect to the control server.
+// notInMapPollWarnable is a Warnable that warns the user that we are using a stale network map.
 var notInMapPollWarnable = Register(&Warnable{
 	Code:      "not-in-map-poll",
-	Title:     "Cannot connect to control server",
+	Title:     "Out of sync",
 	Severity:  SeverityMedium,
 	DependsOn: []*Warnable{NetworkStatusWarnable},
-	Text:      StaticMessage("Cannot connect to the control server (not in map poll). Check your Internet connection."),
+	Text:      StaticMessage("Unable to connect to the Tailscale coordination server to synchronize the state of your tailnet. Peer reachability might degrade over time."),
 })
 
 // noDERPHomeWarnable is a Warnable that warns the user that Tailscale doesn't have a home DERP.