From 71bf071b183e02531bd8d8b8e73617dcdf91ad4c Mon Sep 17 00:00:00 2001
From: p_caiwfeng <p_caiwfeng@tencent.com>
Date: Sat, 21 Aug 2021 23:52:53 +0800
Subject: [PATCH] support linux dns resolve, short domain name resolve

---
 dns/dns_linux.go | 30 ++++++++++++++++++++++++++++++
 dns/dns_unix.go  |  2 +-
 pkg/main.go      | 12 +++++++-----
 3 files changed, 38 insertions(+), 6 deletions(-)
 create mode 100644 dns/dns_linux.go

diff --git a/dns/dns_linux.go b/dns/dns_linux.go
new file mode 100644
index 00000000..6bf8d0b5
--- /dev/null
+++ b/dns/dns_linux.go
@@ -0,0 +1,30 @@
+// +build linux
+
+package dns
+
+import (
+	log "github.com/sirupsen/logrus"
+	"os"
+	"os/exec"
+)
+
+func DNS(ip string, namespace string) error {
+	tunName := os.Getenv("tunName")
+	if len(tunName) == 0 {
+		tunName = "tun0"
+	}
+	cmd := exec.Command("systemd-resolve", []string{
+		"--set-dns",
+		ip,
+		"--interface",
+		tunName,
+		"--set-domain=" + namespace + ".svc.cluster.local",
+		"--set-domain=svc.cluster.local",
+	}...)
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Warnf("cmd: %s, output: %s, error: %v\n", cmd.Args, string(output), err)
+	}
+
+	return nil
+}
diff --git a/dns/dns_unix.go b/dns/dns_unix.go
index 9310078e..77c07f22 100644
--- a/dns/dns_unix.go
+++ b/dns/dns_unix.go
@@ -1,4 +1,4 @@
-// +build !windows
+// +build darwin
 
 package dns
 
diff --git a/pkg/main.go b/pkg/main.go
index d37f8e2e..9b4b28a2 100644
--- a/pkg/main.go
+++ b/pkg/main.go
@@ -170,11 +170,7 @@ func main() {
 	if err := start(); err != nil {
 		log.Fatal(err)
 	}
-	//time.Sleep(time.Second * 5)
-	dnsServiceIp := util.GetDNSServiceIpFromPod(clientset, restclient, config, util.TrafficManager, namespace)
-	if err := dns.DNS(dnsServiceIp, namespace); err != nil {
-		log.Fatal(err)
-	}
+
 	if runtime.GOOS == "windows" {
 		if !util.FindRule() {
 			util.AddFirewallRule()
@@ -183,6 +179,12 @@ func main() {
 	}
 	log.Info("dns service ok")
 	_ = exec.Command("ping", "-c", "4", "223.254.254.100").Run()
+
+	//time.Sleep(time.Second * 5)
+	dnsServiceIp := util.GetDNSServiceIpFromPod(clientset, restclient, config, util.TrafficManager, namespace)
+	if err := dns.DNS(dnsServiceIp, namespace); err != nil {
+		log.Fatal(err)
+	}
 	select {}
 }