Retry connecting to upstream servers

Rate-limit retries in case connecting immediately fails.

server.go

@@ -12,6 +12,7 @@ import (
 
 // TODO: make configurable
 var keepAlivePeriod = time.Minute
+var retryConnectMinDelay = time.Minute
 
 func setKeepAlive(c net.Conn) error {
 	tcpConn, ok := c.(*net.TCPConn)
@@ -137,22 +138,20 @@ func (s *Server) prefix() *irc.Prefix {
 	return &irc.Prefix{Name: s.Hostname}
 }
 
-func (s *Server) Run() {
-	// TODO: multi-user
-	u := newUser(s, "jounce")
+func (s *Server) runUpstream(u *user, upstream *Upstream) {
+	var lastTry time.Time
+	for {
+		if dur := time.Now().Sub(lastTry); dur < retryConnectMinDelay {
+			delay := retryConnectMinDelay - dur
+			s.Logger.Printf("waiting %v before trying to reconnect to %q", delay.Truncate(time.Second), upstream.Addr)
+			time.Sleep(delay)
+		}
+		lastTry = time.Now()
 
-	s.lock.Lock()
-	s.users[u.username] = u
-	s.lock.Unlock()
-
-	for i := range s.Upstreams {
-		upstream := &s.Upstreams[i]
-		// TODO: retry connecting
-		go func() {
 		uc, err := connectToUpstream(u, upstream)
 		if err != nil {
 			s.Logger.Printf("failed to connect to upstream server %q: %v", upstream.Addr, err)
-				return
+			continue
 		}
 
 		uc.register()
@@ -174,7 +173,19 @@ func (s *Server) Run() {
 			}
 		}
 		u.lock.Unlock()
-		}()
+	}
+}
+
+func (s *Server) Run() {
+	// TODO: multi-user
+	u := newUser(s, "jounce")
+
+	s.lock.Lock()
+	s.users[u.username] = u
+	s.lock.Unlock()
+
+	for i := range s.Upstreams {
+		go s.runUpstream(u, &s.Upstreams[i])
 	}
 }