net/netmon: publish events to event bus

Updates #15160

Signed-off-by: David Anderson <dave@tailscale.com>

cmd/derper/depaware.txt

@@ -156,6 +156,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
      💣 tailscale.com/util/deephash                                  from tailscale.com/util/syspolicy/setting
    L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
         tailscale.com/util/dnsname                                   from tailscale.com/hostinfo+
+        tailscale.com/util/eventbus                                  from tailscale.com/net/netmon
      💣 tailscale.com/util/hashx                                     from tailscale.com/util/deephash
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale
         tailscale.com/util/lineiter                                  from tailscale.com/hostinfo+
@@ -309,7 +310,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         hash/fnv                                                     from google.golang.org/protobuf/internal/detrand
         hash/maphash                                                 from go4.org/mem
         html                                                         from net/http/pprof+
-        html/template                                                from tailscale.com/cmd/derper
+        html/template                                                from tailscale.com/cmd/derper+
         internal/abi                                                 from crypto/x509/internal/macos+
         internal/asan                                                from internal/runtime/maps+
         internal/bisect                                              from internal/godebug

cmd/tailscale/cli/debug.go

@@ -43,6 +43,7 @@ import (
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
+	"tailscale.com/util/eventbus"
 	"tailscale.com/util/must"
 )
 
@@ -956,7 +957,10 @@ func runTS2021(ctx context.Context, args []string) error {
 		logf = log.Printf
 	}
 
-	netMon, err := netmon.New(logger.WithPrefix(logf, "netmon: "))
+	bus := eventbus.New()
+	defer bus.Close()
+
+	netMon, err := netmon.New(bus, logger.WithPrefix(logf, "netmon: "))
 	if err != nil {
 		return fmt.Errorf("creating netmon: %w", err)
 	}

cmd/tailscale/cli/netcheck.go

@@ -24,6 +24,7 @@ import (
 	"tailscale.com/net/tlsdial"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
+	"tailscale.com/util/eventbus"
 )
 
 var netcheckCmd = &ffcli.Command{
@@ -48,7 +49,9 @@ var netcheckArgs struct {
 
 func runNetcheck(ctx context.Context, args []string) error {
 	logf := logger.WithPrefix(log.Printf, "portmap: ")
-	netMon, err := netmon.New(logf)
+	bus := eventbus.New()
+	defer bus.Close()
+	netMon, err := netmon.New(bus, logf)
 	if err != nil {
 		return err
 	}

cmd/tailscale/depaware.txt

@@ -163,7 +163,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
      💣 tailscale.com/util/deephash                                  from tailscale.com/util/syspolicy/setting
    L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
         tailscale.com/util/dnsname                                   from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/util/eventbus                                  from tailscale.com/net/portmapper
+        tailscale.com/util/eventbus                                  from tailscale.com/net/portmapper+
         tailscale.com/util/groupmember                               from tailscale.com/client/web
      💣 tailscale.com/util/hashx                                     from tailscale.com/util/deephash
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale+

cmd/tailscaled/debug.go

@@ -27,6 +27,7 @@ import (
 	"tailscale.com/net/tshttpproxy"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
+	"tailscale.com/util/eventbus"
 )
 
 var debugArgs struct {
@@ -72,11 +73,14 @@ func debugMode(args []string) error {
 }
 
 func runMonitor(ctx context.Context, loop bool) error {
+	b := eventbus.New()
+	defer b.Close()
+
 	dump := func(st *netmon.State) {
 		j, _ := json.MarshalIndent(st, "", "    ")
 		os.Stderr.Write(j)
 	}
-	mon, err := netmon.New(log.Printf)
+	mon, err := netmon.New(b, log.Printf)
 	if err != nil {
 		return err
 	}

cmd/tailscaled/tailscaled.go

@@ -391,7 +391,7 @@ func run() (err error) {
 	var netMon *netmon.Monitor
 	isWinSvc := isWindowsService()
 	if !isWinSvc {
-		netMon, err = netmon.New(logf)
+		netMon, err = netmon.New(sys.Bus.Get(), logf)
 		if err != nil {
 			return fmt.Errorf("netmon.New: %w", err)
 		}

cmd/tailscaled/tailscaled_windows.go

@@ -329,7 +329,7 @@ func beWindowsSubprocess() bool {
 	}
 
 	sys := tsd.NewSystem()
-	netMon, err := netmon.New(log.Printf)
+	netMon, err := netmon.New(sys.Bus.Get(), log.Printf)
 	if err != nil {
 		log.Fatalf("Could not create netMon: %v", err)
 	}