ipn/ipnstate: add PeerStatus.KeyExpiry for tailscale status --json

Fixes #6712

Change-Id: I817cd5342fac8a956fcefda2d63158fa488f3395
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/derper/depaware.txt

@@ -69,7 +69,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/types/opt                                      from tailscale.com/client/tailscale+
         tailscale.com/types/persist                                  from tailscale.com/ipn
         tailscale.com/types/preftype                                 from tailscale.com/ipn
-        tailscale.com/types/ptr                                      from tailscale.com/hostinfo
+        tailscale.com/types/ptr                                      from tailscale.com/hostinfo+
         tailscale.com/types/structs                                  from tailscale.com/ipn+
         tailscale.com/types/tkatype                                  from tailscale.com/types/key+
         tailscale.com/types/views                                    from tailscale.com/ipn/ipnstate+

cmd/tailscale/depaware.txt

@@ -98,7 +98,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/types/opt                                      from tailscale.com/net/netcheck+
         tailscale.com/types/persist                                  from tailscale.com/ipn
         tailscale.com/types/preftype                                 from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/types/ptr                                      from tailscale.com/hostinfo
+        tailscale.com/types/ptr                                      from tailscale.com/hostinfo+
         tailscale.com/types/structs                                  from tailscale.com/ipn+
         tailscale.com/types/tkatype                                  from tailscale.com/types/key+
         tailscale.com/types/views                                    from tailscale.com/tailcfg+

ipn/ipnlocal/local.go

@@ -723,6 +723,10 @@ func peerStatusFromNode(ps *ipnstate.PeerStatus, n *tailcfg.Node) {
 	if n.Expired {
 		ps.Expired = true
 	}
+	if t := n.KeyExpiry; !t.IsZero() {
+		t = t.Round(time.Second)
+		ps.KeyExpiry = &t
+	}
 }
 
 // WhoIs reports the node and user who owns the node with the given IP:port.

ipn/ipnstate/ipnstate.go

@@ -20,6 +20,7 @@ import (
 
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
+	"tailscale.com/types/ptr"
 	"tailscale.com/types/views"
 	"tailscale.com/util/dnsname"
 )
@@ -251,6 +252,10 @@ type PeerStatus struct {
 	// information from control or optimisically set on the client if the
 	// expiration time has passed.
 	Expired bool `json:",omitempty"`
+
+	// KeyExpiry, if present, is the time at which the node key expired or
+	// will expire.
+	KeyExpiry *time.Time `json:",omitempty"`
 }
 
 type StatusBuilder struct {
@@ -435,6 +440,9 @@ func (sb *StatusBuilder) AddPeer(peer key.NodePublic, st *PeerStatus) {
 	if st.Expired {
 		e.Expired = true
 	}
+	if t := st.KeyExpiry; t != nil {
+		e.KeyExpiry = ptr.To(*t)
+	}
 }
 
 type StatusUpdater interface {