ipn/{ipnlocal,localapi}: export varz via v2n, peerapi and localapi

Updates #cleanup

Signed-off-by: Anton Tolchanov <anton@tailscale.com>

cmd/tailscaled/tailscaled.go

@@ -791,10 +791,8 @@ func newNetstack(logf logger.Logf, sys *tsd.System) (*netstack.Impl, error) {
 	if err != nil {
 		return nil, err
 	}
-	// Only register debug info if we have a debug mux
-	if debugMux != nil {
-		expvar.Publish("netstack", ret.ExpVar())
-	}
+	// These are exposed via the local debug server, c2n, peerapi and localapi.
+	expvar.Publish("netstack", ret.ExpVar())
 	return ret, nil
 }
 

ipn/ipnlocal/c2n.go

@@ -29,6 +29,7 @@ import (
 	"tailscale.com/net/sockstats"
 	"tailscale.com/posture"
 	"tailscale.com/tailcfg"
+	"tailscale.com/tsweb/varz"
 	"tailscale.com/util/clientmetric"
 	"tailscale.com/util/goroutines"
 	"tailscale.com/util/set"
@@ -151,6 +152,7 @@ func handleC2NDebugPrefs(b *LocalBackend, w http.ResponseWriter, r *http.Request
 
 func handleC2NDebugMetrics(_ *LocalBackend, w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/plain")
+	varz.Handler(w, r)
 	clientmetric.WritePrometheusExpositionFormat(w)
 }
 

ipn/ipnlocal/peerapi.go

@@ -40,6 +40,7 @@ import (
 	"tailscale.com/net/sockstats"
 	"tailscale.com/tailcfg"
 	"tailscale.com/taildrop"
+	"tailscale.com/tsweb/varz"
 	"tailscale.com/types/views"
 	"tailscale.com/util/clientmetric"
 	"tailscale.com/util/httphdr"
@@ -799,6 +800,7 @@ func (h *peerAPIHandler) handleServeMetrics(w http.ResponseWriter, r *http.Reque
 		return
 	}
 	w.Header().Set("Content-Type", "text/plain")
+	varz.Handler(w, r)
 	clientmetric.WritePrometheusExpositionFormat(w)
 }
 

ipn/localapi/localapi.go

@@ -50,6 +50,7 @@ import (
 	"tailscale.com/taildrop"
 	"tailscale.com/tka"
 	"tailscale.com/tstime"
+	"tailscale.com/tsweb/varz"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/logid"
@@ -568,6 +569,7 @@ func (h *Handler) serveMetrics(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	w.Header().Set("Content-Type", "text/plain")
+	varz.Handler(w, r)
 	clientmetric.WritePrometheusExpositionFormat(w)
 }