From da774f767952d2eb834c89dd81bfcc97cd404fa0 Mon Sep 17 00:00:00 2001
From: afeiszli <alex.feiszli@gmail.com>
Date: Mon, 23 May 2022 10:02:47 -0400
Subject: [PATCH] removing legacy DNS logic

---
 netclient/local/dns.go        | 149 ----------------------------------
 netclient/wireguard/common.go |   6 +-
 2 files changed, 2 insertions(+), 153 deletions(-)
 delete mode 100644 netclient/local/dns.go

diff --git a/netclient/local/dns.go b/netclient/local/dns.go
deleted file mode 100644
index 1f168b34..00000000
--- a/netclient/local/dns.go
+++ /dev/null
@@ -1,149 +0,0 @@
-package local
-
-import (
-	"fmt"
-	"net"
-	"os"
-	"strings"
-	"time"
-
-	//"github.com/davecgh/go-spew/spew"
-	"log"
-	"os/exec"
-
-	"github.com/gravitl/netmaker/logger"
-	"github.com/gravitl/netmaker/models"
-	"github.com/gravitl/netmaker/netclient/ncutils"
-)
-
-const DNS_UNREACHABLE_ERROR = "nameserver unreachable"
-
-// SetDNSWithRetry - Attempt setting dns, if it fails return true (to reset dns)
-func SetDNSWithRetry(node models.Node, address string) bool {
-	var reachable bool
-	if !hasPrereqs() {
-		return true
-	}
-	for counter := 0; !reachable && counter < 5; counter++ {
-		reachable = IsDNSReachable(address)
-		time.Sleep(time.Second << 1)
-	}
-	if !reachable {
-		logger.Log(0, "not setting dns (server unreachable), will try again later: "+address)
-		return true
-	} else if err := UpdateDNS(node.Interface, node.Network, address); err != nil {
-		logger.Log(0, "error applying dns"+err.Error())
-	} else if IsDNSWorking(node.Network, address) {
-		return true
-	}
-	resetDNS()
-	return false
-}
-
-func resetDNS() {
-	ncutils.RunCmd("systemctl restart systemd-resolved", true)
-}
-
-// SetDNS - sets the DNS of a local machine
-func SetDNS(nameserver string) error {
-	bytes, err := os.ReadFile("/etc/resolv.conf")
-	if err != nil {
-		return err
-	}
-	resolvstring := string(bytes)
-	// //check whether s contains substring text
-	hasdns := strings.Contains(resolvstring, nameserver)
-	if hasdns {
-		return nil
-	}
-	resolv, err := os.OpenFile("/etc/resolv.conf", os.O_APPEND|os.O_WRONLY, 0644)
-	if err != nil {
-		return err
-	}
-	defer resolv.Close()
-	_, err = resolv.WriteString("nameserver " + nameserver + "\n")
-
-	return err
-}
-
-func hasPrereqs() bool {
-	if !ncutils.IsLinux() {
-		return false
-	}
-	_, err := exec.LookPath("resolvectl")
-	return err == nil
-}
-
-// UpdateDNS - updates local DNS of client
-func UpdateDNS(ifacename string, network string, nameserver string) error {
-	if !ncutils.IsLinux() {
-		return nil
-	}
-	if ifacename == "" {
-		return fmt.Errorf("cannot set dns: interface name is blank")
-	}
-	if network == "" {
-		return fmt.Errorf("cannot set dns: network name is blank")
-	}
-	if nameserver == "" {
-		return fmt.Errorf("cannot set dns: nameserver is blank")
-	}
-	if !IsDNSReachable(nameserver) {
-		return fmt.Errorf(DNS_UNREACHABLE_ERROR + " : " + nameserver + ":53")
-	}
-	_, err := exec.LookPath("resolvectl")
-	if err != nil {
-		log.Println(err)
-		log.Println("WARNING: resolvectl not present. Unable to set dns. Install resolvectl or run manually.")
-	} else {
-		_, err = ncutils.RunCmd("resolvectl domain "+ifacename+" ~"+network, true)
-		if err != nil {
-			log.Println("WARNING: Error encountered setting domain on dns. Aborted setting dns.")
-		} else {
-			_, err = ncutils.RunCmd("resolvectl default-route "+ifacename+" false", true)
-			if err != nil {
-				log.Println("WARNING: Error encountered setting default-route on dns. Aborted setting dns.")
-			} else {
-				_, err = ncutils.RunCmd("resolvectl dns "+ifacename+" "+nameserver, true)
-				if err != nil {
-					log.Println("WARNING: Error encountered running resolvectl dns " + ifacename + " " + nameserver)
-				}
-			}
-		}
-	}
-	return err
-}
-
-// IsDNSReachable - checks if nameserver is reachable
-func IsDNSReachable(nameserver string) bool {
-	port := "53"
-	protocols := [2]string{"tcp", "udp"}
-	for _, proto := range protocols {
-		timeout := time.Second
-		conn, err := net.DialTimeout(proto, net.JoinHostPort(nameserver, port), timeout)
-		if err != nil {
-			return false
-		}
-		if conn != nil {
-			defer conn.Close()
-		} else {
-			return false
-		}
-	}
-	return true
-}
-
-// IsDNSWorking - checks if record is returned by correct nameserver
-func IsDNSWorking(network string, nameserver string) bool {
-	var isworking bool
-	servers, err := net.LookupNS("netmaker" + "." + network)
-	if err != nil {
-		return isworking
-	}
-	for _, ns := range servers {
-		if strings.Contains(ns.Host, nameserver) {
-			isworking = true
-		}
-	}
-	return isworking
-}
diff --git a/netclient/wireguard/common.go b/netclient/wireguard/common.go
index 04f0871c..d96241ea 100644
--- a/netclient/wireguard/common.go
+++ b/netclient/wireguard/common.go
@@ -245,7 +245,7 @@ func SetWGConfig(network string, peerupdate bool, peers []wgtypes.PeerConfig) er
 	if err != nil {
 		return err
 	}
-	servercfg := cfg.Server
+
 	nodecfg := cfg.Node
 
 	privkey, err := RetrievePrivKey(network)
@@ -267,9 +267,7 @@ func SetWGConfig(network string, peerupdate bool, peers []wgtypes.PeerConfig) er
 	} else {
 		err = InitWireguard(&nodecfg, privkey, peers, false)
 	}
-	if nodecfg.DNSOn == "yes" {
-		_ = local.UpdateDNS(nodecfg.Interface, nodecfg.Network, servercfg.CoreDNSAddr)
-	}
+
 	return err
 }