net/dns/resolver: remove unused err return value.

Signed-off-by: David Anderson <danderson@tailscale.com>

net/dns/resolver/tsdns.go

@@ -98,7 +98,7 @@ type Resolver struct {
 
 // New returns a new resolver.
 // linkMon optionally specifies a link monitor to use for socket rebinding.
-func New(logf logger.Logf, linkMon *monitor.Mon) (*Resolver, error) {
+func New(logf logger.Logf, linkMon *monitor.Mon) *Resolver {
 	r := &Resolver{
 		logf:      logger.WithPrefix(logf, "dns: "),
 		linkMon:   linkMon,
@@ -117,7 +117,7 @@ func New(logf logger.Logf, linkMon *monitor.Mon) (*Resolver, error) {
 	r.wg.Add(1)
 	go r.poll()
 
-	return r, nil
+	return r
 }
 
 func isFQDN(s string) bool {

net/dns/resolver/tsdns_test.go

@@ -187,10 +187,7 @@ func TestRDNSNameToIPv6(t *testing.T) {
 }
 
 func TestResolveLocal(t *testing.T) {
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	r.SetConfig(dnsCfg)
@@ -230,10 +227,7 @@ func TestResolveLocal(t *testing.T) {
 }
 
 func TestResolveLocalReverse(t *testing.T) {
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	r.SetConfig(dnsCfg)
@@ -287,10 +281,7 @@ func TestDelegate(t *testing.T) {
 		"nxdomain.site.", resolveToNXDOMAIN)
 	defer v6server.Shutdown()
 
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	cfg := dnsCfg
@@ -365,10 +356,7 @@ func TestDelegateSplitRoute(t *testing.T) {
 		"test.other.", resolveToIP(test4, test6, "dns.other."))
 	defer server2.Shutdown()
 
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	cfg := dnsCfg
@@ -425,10 +413,7 @@ func TestDelegateCollision(t *testing.T) {
 		"test.site.", resolveToIP(testipv4, testipv6, "dns.test.site."))
 	defer server.Shutdown()
 
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	cfg := dnsCfg
@@ -642,10 +627,7 @@ var emptyResponse = []byte{
 }
 
 func TestFull(t *testing.T) {
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	r.SetConfig(dnsCfg)
@@ -681,10 +663,7 @@ func TestFull(t *testing.T) {
 }
 
 func TestAllocs(t *testing.T) {
-	r, err := New(t.Logf, nil)
+	r := New(t.Logf, nil)
-	if err != nil {
-		t.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 	r.SetConfig(dnsCfg)
 
@@ -739,10 +718,7 @@ func BenchmarkFull(b *testing.B) {
 		"test.site.", resolveToIP(testipv4, testipv6, "dns.test.site."))
 	defer server.Shutdown()
 
-	r, err := New(b.Logf, nil)
+	r := New(b.Logf, nil)
-	if err != nil {
-		b.Fatalf("start: %v", err)
-	}
 	defer r.Close()
 
 	cfg := dnsCfg

wgengine/userspace.go

@@ -230,11 +230,7 @@ func NewUserspaceEngine(logf logger.Logf, conf Config) (_ Engine, reterr error)
 		e.linkMonOwned = true
 	}
 
-	var err error
+	e.resolver = resolver.New(logf, e.linkMon)
-	e.resolver, err = resolver.New(logf, e.linkMon)
-	if err != nil {
-		return nil, err
-	}
 
 	logf("link state: %+v", e.linkMon.InterfaceState())
 
@@ -262,6 +258,7 @@ func NewUserspaceEngine(logf logger.Logf, conf Config) (_ Engine, reterr error)
 		LinkMonitor:      e.linkMon,
 	}
 
+	var err error
 	e.magicConn, err = magicsock.NewConn(magicsockOpts)
 	if err != nil {
 		return nil, fmt.Errorf("wgengine: %v", err)