Better tracking of SFTP events

server/manager.go

@@ -52,6 +52,24 @@ func (m *Manager) Client() remote.Client {
 	return m.client
 }
 
+// Len returns the count of servers stored in the manager instance.
+func (m *Manager) Len() int {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return len(m.servers)
+}
+
+// Keys returns all of the server UUIDs stored in the manager set.
+func (m *Manager) Keys() []string {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	keys := make([]string, len(m.servers))
+	for i, s := range m.servers {
+		keys[i] = s.ID()
+	}
+	return keys
+}
+
 // Put replaces all the current values in the collection with the value that
 // is passed through.
 func (m *Manager) Put(s []*Server) {