cmd/tailscale: change formatting of "tailscale status"

* show DNS name over hostname, removing domain's common MagicDNS suffix.
  only show hostname if there's no DNS name.
  but still show shared devices' MagicDNS FQDN.

* remove nerdy low-level details by default: endpoints, DERP relay,
  public key.  They're available in JSON mode still for those who need
  them.

* only show endpoint or DERP relay when it's active with the goal of
  making debugging easier. (so it's easier for users to understand
  what's happening) The asterisks are gone.

* remove Tx/Rx numbers by default for idle peers; only show them when
  there's traffic.

* include peers' owner login names

* add CLI option to not show peers (matching --self=true, --peers= also
  defaults to true)

* sort by DNS/host name, not public key

* reorder columns

cmd/tailscale/cli/status.go

@@ -14,6 +14,8 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"sort"
+	"strings"
 	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
@@ -21,6 +23,7 @@ import (
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/net/interfaces"
+	"tailscale.com/util/dnsname"
 )
 
 var statusCmd = &ffcli.Command{
@@ -34,6 +37,7 @@ var statusCmd = &ffcli.Command{
 		fs.BoolVar(&statusArgs.web, "web", false, "run webserver with HTML showing status")
 		fs.BoolVar(&statusArgs.active, "active", false, "filter output to only peers with active sessions (not applicable to web mode)")
 		fs.BoolVar(&statusArgs.self, "self", true, "show status of local machine")
+		fs.BoolVar(&statusArgs.peers, "peers", true, "show status of peers")
 		fs.StringVar(&statusArgs.listen, "listen", "127.0.0.1:8384", "listen address; use port 0 for automatic")
 		fs.BoolVar(&statusArgs.browser, "browser", true, "Open a browser in web mode")
 		return fs
@@ -47,6 +51,7 @@ var statusArgs struct {
 	browser bool   // in web mode, whether to open browser
 	active  bool   // in CLI mode, filter output to only peers with active sessions
 	self    bool   // in CLI mode, show status of local machine
+	peers   bool   // in CLI mode, show status of peer machines
 }
 
 func runStatus(ctx context.Context, args []string) error {
@@ -136,48 +141,55 @@ func runStatus(ctx context.Context, args []string) error {
 	f := func(format string, a ...interface{}) { fmt.Fprintf(&buf, format, a...) }
 	printPS := func(ps *ipnstate.PeerStatus) {
 		active := peerActive(ps)
-		f("%s %-7s %-15s %-18s tx=%8d rx=%8d ",
-			ps.PublicKey.ShortString(),
-			ps.OS,
+		f("%-15s %-20s %-12s %-7s ",
 			ps.TailAddr,
-			ps.SimpleHostName(),
-			ps.TxBytes,
-			ps.RxBytes,
+			dnsOrQuoteHostname(st, ps),
+			ownerLogin(st, ps),
+			ps.OS,
 		)
 		relay := ps.Relay
-		if active && relay != "" && ps.CurAddr == "" {
-			relay = "*" + relay + "*"
+		anyTraffic := ps.TxBytes != 0 || ps.RxBytes != 0
+		if !active {
+			if anyTraffic {
+				f("idle")
 			} else {
-			relay = " " + relay
-		}
-		f("%-6s", relay)
-		for i, addr := range ps.Addrs {
-			if i != 0 {
-				f(", ")
+				f("-")
 			}
-			if addr == ps.CurAddr {
-				f("*%s*", addr)
 		} else {
-				f("%s", addr)
+			f("active; ")
+			if relay != "" && ps.CurAddr == "" {
+				f("relay %q", relay)
+			} else if ps.CurAddr != "" {
+				f("direct %s", ps.CurAddr)
 			}
 		}
+		if anyTraffic {
+			f(", tx %d rx %d", ps.TxBytes, ps.RxBytes)
+		}
 		f("\n")
 	}
 
 	if statusArgs.self && st.Self != nil {
 		printPS(st.Self)
 	}
+	if statusArgs.peers {
+		var peers []*ipnstate.PeerStatus
 		for _, peer := range st.Peers() {
 			ps := st.Peer[peer]
 			if ps.ShareeNode {
 				continue
 			}
+			peers = append(peers, ps)
+		}
+		sort.Slice(peers, func(i, j int) bool { return sortKey(peers[i]) < sortKey(peers[j]) })
+		for _, ps := range peers {
 			active := peerActive(ps)
 			if statusArgs.active && !active {
 				continue
 			}
 			printPS(ps)
 		}
+	}
 	os.Stdout.Write(buf.Bytes())
 	return nil
 }
@@ -188,3 +200,37 @@ func runStatus(ctx context.Context, args []string) error {
 func peerActive(ps *ipnstate.PeerStatus) bool {
 	return !ps.LastWrite.IsZero() && time.Since(ps.LastWrite) < 2*time.Minute
 }
+
+func dnsOrQuoteHostname(st *ipnstate.Status, ps *ipnstate.PeerStatus) string {
+	if i := strings.Index(ps.DNSName, "."); i != -1 && dnsname.HasSuffix(ps.DNSName, st.MagicDNSSuffix) {
+		return ps.DNSName[:i]
+	}
+	if ps.DNSName != "" {
+		return ps.DNSName
+	}
+	return fmt.Sprintf("- (%q)", ps.SimpleHostName())
+}
+
+func sortKey(ps *ipnstate.PeerStatus) string {
+	if ps.DNSName != "" {
+		return ps.DNSName
+	}
+	if ps.HostName != "" {
+		return ps.HostName
+	}
+	return ps.TailAddr
+}
+
+func ownerLogin(st *ipnstate.Status, ps *ipnstate.PeerStatus) string {
+	if ps.UserID.IsZero() {
+		return "-"
+	}
+	u, ok := st.User[ps.UserID]
+	if !ok {
+		return fmt.Sprint(ps.UserID)
+	}
+	if i := strings.Index(u.LoginName, "@"); i != -1 {
+		return u.LoginName[:i+1]
+	}
+	return u.LoginName
+}

cmd/tailscale/depaware.txt

@@ -74,6 +74,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/types/strbuilder                               from tailscale.com/net/packet
         tailscale.com/types/structs                                  from tailscale.com/control/controlclient+
         tailscale.com/types/wgkey                                    from tailscale.com/control/controlclient+
+        tailscale.com/util/dnsname                                   from tailscale.com/cmd/tailscale/cli+
   LW    tailscale.com/util/endian                                    from tailscale.com/net/netns+
         tailscale.com/util/lineread                                  from tailscale.com/control/controlclient+
         tailscale.com/util/systemd                                   from tailscale.com/control/controlclient+

cmd/tailscaled/depaware.txt

@@ -82,6 +82,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/types/strbuilder                               from tailscale.com/net/packet
         tailscale.com/types/structs                                  from tailscale.com/control/controlclient+
         tailscale.com/types/wgkey                                    from tailscale.com/control/controlclient+
+        tailscale.com/util/dnsname                                   from tailscale.com/control/controlclient+
   LW    tailscale.com/util/endian                                    from tailscale.com/net/netns+
         tailscale.com/util/lineread                                  from tailscale.com/control/controlclient+
         tailscale.com/util/pidowner                                  from tailscale.com/ipn/ipnserver

control/controlclient/netmap.go

@@ -18,6 +18,7 @@ import (
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/wgkey"
+	"tailscale.com/util/dnsname"
 	"tailscale.com/wgengine/filter"
 )
 
@@ -56,7 +57,30 @@ type NetworkMap struct {
 	// TODO(crawshaw): Capabilities []tailcfg.Capability
 }
 
-func (nm NetworkMap) String() string {
+// MagicDNSSuffix returns the domain's MagicDNS suffix, or empty if none.
+// If non-empty, it will neither start nor end with a period.
+func (nm *NetworkMap) MagicDNSSuffix() string {
+	searchPathUsedAsDNSSuffix := func(suffix string) bool {
+		if dnsname.HasSuffix(nm.Name, suffix) {
+			return true
+		}
+		for _, p := range nm.Peers {
+			if dnsname.HasSuffix(p.Name, suffix) {
+				return true
+			}
+		}
+		return false
+	}
+
+	for _, d := range nm.DNS.Domains {
+		if searchPathUsedAsDNSSuffix(d) {
+			return strings.Trim(d, ".")
+		}
+	}
+	return ""
+}
+
+func (nm *NetworkMap) String() string {
 	return nm.Concise()
 }
 

ipn/ipnstate/ipnstate.go

@@ -28,6 +28,7 @@ type Status struct {
 	BackendState   string
 	TailscaleIPs   []netaddr.IP // Tailscale IP(s) assigned to this node
 	Self           *PeerStatus
+	MagicDNSSuffix string // e.g. "userfoo.tailscale.net" (no surrounding dots)
 
 	Peer map[key.Public]*PeerStatus
 	User map[tailcfg.UserID]tailcfg.UserProfile
@@ -103,6 +104,12 @@ func (sb *StatusBuilder) SetBackendState(v string) {
 	sb.st.BackendState = v
 }
 
+func (sb *StatusBuilder) SetMagicDNSSuffix(v string) {
+	sb.mu.Lock()
+	defer sb.mu.Unlock()
+	sb.st.MagicDNSSuffix = v
+}
+
 func (sb *StatusBuilder) Status() *Status {
 	sb.mu.Lock()
 	defer sb.mu.Unlock()

ipn/local.go

@@ -201,6 +201,7 @@ func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) {
 	// TODO: hostinfo, and its networkinfo
 	// TODO: EngineStatus copy (and deprecate it?)
 	if b.netMap != nil {
+		sb.SetMagicDNSSuffix(b.netMap.MagicDNSSuffix())
 		for id, up := range b.netMap.UserProfiles {
 			sb.AddUser(id, up)
 		}
@@ -1232,28 +1233,10 @@ func (b *LocalBackend) authReconfig() {
 // magicDNSRootDomains returns the subset of nm.DNS.Domains that are the search domains for MagicDNS.
 // Each entry has a trailing period.
 func magicDNSRootDomains(nm *controlclient.NetworkMap) []string {
-	searchPathUsedAsDNSSuffix := func(suffix string) bool {
-		if tsdns.NameHasSuffix(nm.Name, suffix) {
-			return true
-		}
-		for _, p := range nm.Peers {
-			if tsdns.NameHasSuffix(p.Name, suffix) {
-				return true
-			}
-		}
-		return false
+	if v := nm.MagicDNSSuffix(); v != "" {
+		return []string{strings.Trim(v, ".") + "."}
 	}
-
-	var ret []string
-	for _, d := range nm.DNS.Domains {
-		if searchPathUsedAsDNSSuffix(d) {
-			if !strings.HasSuffix(d, ".") {
-				d += "."
-			}
-			ret = append(ret, d)
-		}
-	}
-	return ret
+	return nil
 }
 
 // routerConfig produces a router.Config from a wireguard config and IPN prefs.

util/dnsname/dnsname.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package dnsname contains string functions for working with DNS names.
+package dnsname
+
+import "strings"
+
+// HasSuffix reports whether the provided DNS name ends with the
+// component(s) in suffix, ignoring any trailing dots.
+//
+// If suffix is the empty string, HasSuffix always reports false.
+func HasSuffix(name, suffix string) bool {
+	name = strings.TrimSuffix(name, ".")
+	suffix = strings.TrimSuffix(suffix, ".")
+	nameBase := strings.TrimSuffix(name, suffix)
+	return len(nameBase) < len(name) && strings.HasSuffix(nameBase, ".")
+}

util/dnsname/dnsname_test.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package dnsname
+
+import "testing"
+
+func TestHasSuffix(t *testing.T) {
+	tests := []struct {
+		name, suffix string
+		want         bool
+	}{
+		{"foo.com", "com", true},
+		{"foo.com.", "com", true},
+		{"foo.com.", "com.", true},
+
+		{"", "", false},
+		{"foo.com.", "", false},
+		{"foo.com.", "o.com", false},
+	}
+	for _, tt := range tests {
+		got := HasSuffix(tt.name, tt.suffix)
+		if got != tt.want {
+			t.Errorf("HasSuffix(%q, %q) = %v; want %v", tt.name, tt.suffix, got, tt.want)
+		}
+	}
+}

wgengine/magicsock/magicsock.go

@@ -2710,11 +2710,14 @@ func (c *Conn) UpdateStatus(sb *ipnstate.StatusBuilder) {
 	ss := &ipnstate.PeerStatus{
 		PublicKey: c.privateKey.Public(),
 		Addrs:     c.lastEndpoints,
+		OS:        version.OS(),
 	}
 	if c.netMap != nil {
 		ss.HostName = c.netMap.Hostinfo.Hostname
-		ss.OS = version.OS()
 		ss.DNSName = c.netMap.Name
+		ss.UserID = c.netMap.User
+	} else {
+		ss.HostName, _ = os.Hostname()
 	}
 	if c.derpMap != nil {
 		derpRegion, ok := c.derpMap.Regions[c.myDerp]

wgengine/tsdns/tsdns.go

@@ -17,6 +17,7 @@ import (
 	dns "golang.org/x/net/dns/dnsmessage"
 	"inet.af/netaddr"
 	"tailscale.com/types/logger"
+	"tailscale.com/util/dnsname"
 )
 
 // maxResponseBytes is the maximum size of a response from a Resolver.
@@ -195,7 +196,7 @@ func (r *Resolver) Resolve(domain string, tp dns.Type) (netaddr.IP, dns.RCode, e
 
 	anyHasSuffix := false
 	for _, suffix := range dnsMap.rootDomains {
-		if NameHasSuffix(domain, suffix) {
+		if dnsname.HasSuffix(domain, suffix) {
 			anyHasSuffix = true
 			break
 		}
@@ -616,12 +617,3 @@ func (r *Resolver) respond(query []byte) ([]byte, error) {
 
 	return marshalResponse(resp)
 }
-
-// NameHasSuffix reports whether the provided DNS name ends with the
-// component(s) in suffix, ignoring any trailing dots.
-func NameHasSuffix(name, suffix string) bool {
-	name = strings.TrimSuffix(name, ".")
-	suffix = strings.TrimSuffix(suffix, ".")
-	nameBase := strings.TrimSuffix(name, suffix)
-	return len(nameBase) < len(name) && strings.HasSuffix(nameBase, ".")
-}

wgengine/tsdns/tsdns_test.go

@@ -797,24 +797,3 @@ func TestMarshalResponseFormatError(t *testing.T) {
 	}
 	t.Logf("response: %q", v)
 }
-
-func TestNameHasSuffix(t *testing.T) {
-	tests := []struct {
-		name, suffix string
-		want         bool
-	}{
-		{"foo.com", "com", true},
-		{"foo.com.", "com", true},
-		{"foo.com.", "com.", true},
-
-		{"", "", false},
-		{"foo.com.", "", false},
-		{"foo.com.", "o.com", false},
-	}
-	for _, tt := range tests {
-		got := NameHasSuffix(tt.name, tt.suffix)
-		if got != tt.want {
-			t.Errorf("NameHasSuffix(%q, %q) = %v; want %v", tt.name, tt.suffix, got, tt.want)
-		}
-	}
-}