every user login resets agent expiry now.

pkg/agent/session.go

@@ -49,6 +49,7 @@ type AgentState struct {
 	// map of unique session id to a session
 	sessions map[int]*AgentSession
 
+	lastUserLoginTime time.Time
 	agentUsed         bool
 }
 
@@ -88,9 +89,14 @@ func ConfigureAgent(advanceWarningTime, agentExpiryTime, tickerInterval time.Dur
 		tickerInterval:          tickerInterval,
 		ticker:                  time.NewTicker(tickerInterval),
 		sessions:                make(map[int]*AgentSession),
+
+		lastUserLoginTime: time.Time{},
 		agentUsed:         false,
 	}
 
+	log.Printf("Agent expires at %s",
+		state.expiryTime(holdFilename).Format(time.DateTime))
+
 	go func() {
 		for {
 			<-state.ticker.C
@@ -184,6 +190,7 @@ func login(sessionId int, sshSession ssh.Session) {
 		sshSession: sshSession,
 	}
 	state.sessions[sessionId] = &agentSession
+	state.lastUserLoginTime = time.Now()
 	state.agentUsed = true
 	logStatus()
 
@@ -254,11 +261,19 @@ func fileExists(filename string) bool {
 }
 
 func (state *AgentState) expiryTime(filename string) time.Time {
-	stats, err := os.Stat(filename)
-	if err != nil {
+	if !state.agentUsed {
 		return state.startTime.Add(state.agentExpriryTime)
 	}
-	return stats.ModTime().Add(state.agentExpriryTime)
+	expiryTime := time.Time{}
+	stats, err := os.Stat(filename)
+	if err == nil {
+		expiryTime = stats.ModTime().Add(state.agentExpriryTime)
+	}
+	userLoginBaseExpiryTime := state.lastUserLoginTime.Add(state.agentExpriryTime)
+	if userLoginBaseExpiryTime.After(expiryTime) {
+		expiryTime = userLoginBaseExpiryTime
+	}
+	return expiryTime
 }
 
 func holdFileChange() {