From acbd744372f5524e2bf726eb18cf6c8a9a8c5062 Mon Sep 17 00:00:00 2001
From: Alex Kataev <dlyavsehpisem@gmail.com>
Date: Wed, 15 Jul 2020 16:34:28 +0500
Subject: [PATCH] Refactor: additional DNS names registration

---
 plugin/net/watcher.go | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/plugin/net/watcher.go b/plugin/net/watcher.go
index f0c91fdb..c78cb7e1 100644
--- a/plugin/net/watcher.go
+++ b/plugin/net/watcher.go
@@ -29,6 +29,12 @@ func (w *watcher) ContainerStarted(id string) {
 		w.driver.warn("ContainerStarted", "error inspecting container %s: %s", id, err)
 		return
 	}
+
+	domain, err := w.weave.DNSDomain()
+	if err != nil {
+		w.driver.warn("ContainerStarted", "unable to get weave dns domain: %s", err)
+	}
+
 	// check that it's on our network
 	for _, net := range info.NetworkSettings.Networks {
 		network, err := w.driver.findNetworkInfo(net.NetworkID)
@@ -39,11 +45,17 @@ func (w *watcher) ContainerStarted(id string) {
 		if network.isOurs {
 			if w.driver.dns {
 				fqdn := fmt.Sprintf("%s.%s", info.Config.Hostname, info.Config.Domainname)
-				weaveDomain, _ := w.weave.DNSDomain()
-				// Container name is prefixed with '/' so we cut first character
-				name := fmt.Sprintf("%s.%s", info.Name[1:], weaveDomain)
-				aliases := append([]string(nil), fqdn, name)
+
+				aliases := make([]string, 0, len(net.Aliases)+2)
+				aliases = append(aliases, fqdn)
+
+				if len(domain) > 0 && len(info.Name) > 1 && info.Name[0] == "/" {
+					name := fmt.Sprintf("%s.%s", info.Name[1:], domain)
+					aliases = append(aliases, name)
+				}
+
 				aliases = append(aliases, net.Aliases...)
+
 				for _, alias := range aliases {
 					w.driver.debug("ContainerStarted", "going to register %s with weaveDNS", alias)
 					if err := w.weave.RegisterWithDNS(id, alias, net.IPAddress); err != nil {