diff --git a/.gitea/workflows/lint.yml b/.gitea/workflows/job_lint.yml
similarity index 57%
rename from .gitea/workflows/lint.yml
rename to .gitea/workflows/job_lint.yml
index 1cc293dc..a47bf298 100644
--- a/.gitea/workflows/lint.yml
+++ b/.gitea/workflows/job_lint.yml
@@ -1,24 +1,26 @@
 name: lint
+
 on:
   pull_request:
+    types: [opened, reopened, synchronize]
     branches:
     - master
     - v3
+    - v4
+
 jobs:
   lint:
-    name: lint
     runs-on: ubuntu-latest
     steps:
     - name: setup-go
-      uses: actions/setup-go@v3
+      uses: actions/setup-go@v5
       with:
-        go-version: 1.21
+        go-version: 'stable'
     - name: checkout
       uses: actions/checkout@v3
     - name: deps
       run: go get -v -d ./...
     - name: lint
-      uses: https://github.com/golangci/golangci-lint-action@v3.4.0
-      continue-on-error: true
+      uses: https://github.com/golangci/golangci-lint-action@v6
       with:
-        version: v1.52
+        version: 'latest'
diff --git a/.gitea/workflows/pr.yml b/.gitea/workflows/job_test.yml
similarity index 59%
rename from .gitea/workflows/pr.yml
rename to .gitea/workflows/job_test.yml
index b3e67b06..15716f1d 100644
--- a/.gitea/workflows/pr.yml
+++ b/.gitea/workflows/job_test.yml
@@ -1,22 +1,30 @@
-name: pr
+name: test
+
 on:
   pull_request:
+    types: [opened, reopened, synchronize]
     branches:
     - master
     - v3
+    - v4
+  push:
+    branches:
+    - master
+    - v3
+    - v4
+
 jobs:
   test:
-    name: test
     runs-on: ubuntu-latest
     steps:
+    - name: setup-go
+      uses: actions/setup-go@v5
+      with:
+        go-version: 'stable'
     - name: checkout
       uses: actions/checkout@v3
-    - name: setup-go
-      uses: actions/setup-go@v3
-      with:
-        go-version: 1.21
     - name: deps
-      run: go get -v -t -d ./...
+      run: go get -v -d ./...
     - name: test
       env:
         INTEGRATION_TESTS: yes
diff --git a/.golangci.yml b/.golangci.yml
index 524fc7f8..2bb1c300 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -1,44 +1,5 @@
 run:
-  concurrency: 4
+  concurrency: 8
   deadline: 5m
   issues-exit-code: 1
   tests: true
-
-linters-settings:
-  govet:
-    check-shadowing: true
-    enable:
-      - fieldalignment
-
-linters:
-  enable:
-    - govet
-    - deadcode
-    - errcheck
-    - govet
-    - ineffassign
-    - staticcheck
-    - structcheck
-    - typecheck
-    - unused
-    - varcheck
-    - bodyclose
-    - gci
-    - goconst
-    - gocritic
-    - gosimple
-    - gofmt
-    - gofumpt
-    - goimports
-    - revive
-    - gosec
-    - makezero
-    - misspell
-    - nakedret
-    - nestif
-    - nilerr
-    - noctx
-    - prealloc
-    - unconvert
-    - unparam
-  disable-all: false
diff --git a/client/noop.go b/client/noop.go
index 7d570fca..db960e62 100644
--- a/client/noop.go
+++ b/client/noop.go
@@ -222,7 +222,7 @@ func (n *noopClient) Call(ctx context.Context, req Request, rsp interface{}, opt
 	ts := time.Now()
 	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Inc()
 	var sp tracer.Span
-	ctx, sp = n.opts.Tracer.Start(ctx, req.Endpoint()+" rpc-client",
+	ctx, sp = n.opts.Tracer.Start(ctx, "rpc-client",
 		tracer.WithSpanKind(tracer.SpanKindClient),
 		tracer.WithSpanLabels("endpoint", req.Endpoint()),
 	)
@@ -385,7 +385,7 @@ func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption
 	ts := time.Now()
 	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Inc()
 	var sp tracer.Span
-	ctx, sp = n.opts.Tracer.Start(ctx, req.Endpoint()+" rpc-client",
+	ctx, sp = n.opts.Tracer.Start(ctx, "rpc-client",
 		tracer.WithSpanKind(tracer.SpanKindClient),
 		tracer.WithSpanLabels("endpoint", req.Endpoint()),
 	)
diff --git a/logger/slog/slog.go b/logger/slog/slog.go
index ddb46955..ad0aacb1 100644
--- a/logger/slog/slog.go
+++ b/logger/slog/slog.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"log/slog"
 	"os"
+	"reflect"
 	"regexp"
 	"runtime"
 	"strconv"
@@ -171,7 +172,29 @@ func (s *slogLogger) Init(opts ...logger.Option) error {
 	}
 
 	attrs, _ := s.argsAttrs(s.opts.Fields)
-	s.handler = &wrapper{h: slog.NewJSONHandler(s.opts.Out, handleOpt).WithAttrs(attrs)}
+
+	var h slog.Handler
+	if s.opts.Context != nil {
+		if v, ok := s.opts.Context.Value(handlerKey{}).(slog.Handler); ok && v != nil {
+			h = v
+		}
+
+		if fn := s.opts.Context.Value(handlerFnKey{}); fn != nil {
+			if rfn := reflect.ValueOf(fn); rfn.Kind() == reflect.Func {
+				if ret := rfn.Call([]reflect.Value{reflect.ValueOf(s.opts.Out), reflect.ValueOf(handleOpt)}); len(ret) == 1 {
+					if iface, ok := ret[0].Interface().(slog.Handler); ok && iface != nil {
+						h = iface
+					}
+				}
+			}
+		}
+	}
+
+	if h == nil {
+		h = slog.NewJSONHandler(s.opts.Out, handleOpt)
+	}
+
+	s.handler = &wrapper{h: h.WithAttrs(attrs)}
 	s.handler.level.Store(int64(loggerToSlogLevel(s.opts.Level)))
 	s.mu.Unlock()
 
@@ -329,3 +352,15 @@ func (s *slogLogger) argsAttrs(args []interface{}) ([]slog.Attr, error) {
 
 	return attrs, err
 }
+
+type handlerKey struct{}
+
+func WithHandler(h slog.Handler) logger.Option {
+	return logger.SetOption(handlerKey{}, h)
+}
+
+type handlerFnKey struct{}
+
+func WithHandlerFunc(fn any) logger.Option {
+	return logger.SetOption(handlerFnKey{}, fn)
+}
diff --git a/logger/slog/slog_test.go b/logger/slog/slog_test.go
index 7350a8f3..6aa73e81 100644
--- a/logger/slog/slog_test.go
+++ b/logger/slog/slog_test.go
@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"log/slog"
 	"strings"
 	"testing"
 
@@ -14,6 +15,23 @@ import (
 	"go.unistack.org/micro/v3/metadata"
 )
 
+func TestWithHandlerFunc(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.InfoLevel), logger.WithOutput(buf),
+		WithHandlerFunc(slog.NewTextHandler),
+	)
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Info(ctx, "msg1")
+
+	if !bytes.Contains(buf.Bytes(), []byte(`msg=msg1`)) {
+		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
+	}
+}
+
 func TestWithAddFields(t *testing.T) {
 	ctx := context.TODO()
 	buf := bytes.NewBuffer(nil)
diff --git a/logger/unwrap/unwrap.go b/logger/unwrap/unwrap.go
index f1f615a7..8bab179d 100644
--- a/logger/unwrap/unwrap.go
+++ b/logger/unwrap/unwrap.go
@@ -36,14 +36,14 @@ var (
 	circularShortBytes = []byte("<shown>")
 	invalidAngleBytes  = []byte("<invalid>")
 	filteredBytes      = []byte("<filtered>")
-	openBracketBytes   = []byte("[")
-	closeBracketBytes  = []byte("]")
-	percentBytes       = []byte("%")
-	precisionBytes     = []byte(".")
-	openAngleBytes     = []byte("<")
-	closeAngleBytes    = []byte(">")
-	openMapBytes       = []byte("{")
-	closeMapBytes      = []byte("}")
+	// openBracketBytes   = []byte("[")
+	// closeBracketBytes  = []byte("]")
+	percentBytes    = []byte("%")
+	precisionBytes  = []byte(".")
+	openAngleBytes  = []byte("<")
+	closeAngleBytes = []byte(">")
+	openMapBytes    = []byte("{")
+	closeMapBytes   = []byte("}")
 )
 
 type protoMessage interface {
diff --git a/logger/unwrap/unwrap_test.go b/logger/unwrap/unwrap_test.go
index 79f816e8..af55db0a 100644
--- a/logger/unwrap/unwrap_test.go
+++ b/logger/unwrap/unwrap_test.go
@@ -82,12 +82,12 @@ func TestTagged(t *testing.T) {
 func TestTaggedNested(t *testing.T) {
 	type val struct {
 		key string `logger:"take"`
-		val string `logger:"omit"`
+		// val string `logger:"omit"`
 		unk string
 	}
 	type str struct {
-		val *val   `logger:"take"`
-		key string `logger:"omit"`
+		// key string `logger:"omit"`
+		val *val `logger:"take"`
 	}
 
 	var iface interface{}
diff --git a/metadata/metadata_test.go b/metadata/metadata_test.go
index 84738f81..a0932d39 100644
--- a/metadata/metadata_test.go
+++ b/metadata/metadata_test.go
@@ -83,6 +83,7 @@ func TestPassing(t *testing.T) {
 	if ok {
 		t.Fatalf("create outgoing context")
 	}
+	_ = md
 
 	ctx = NewOutgoingContext(ctx, New(1))
 	testCtx(ctx)
diff --git a/micro.go b/micro.go
index 9a9f637d..e2dc1e62 100644
--- a/micro.go
+++ b/micro.go
@@ -65,6 +65,8 @@ func As(b any, target any) bool {
 			break
 		case targetType.Implements(routerType):
 			break
+		case targetType.Implements(tracerType):
+			break
 		default:
 			return false
 		}
diff --git a/options.go b/options.go
index a7172acc..cee1b9bb 100644
--- a/options.go
+++ b/options.go
@@ -294,8 +294,8 @@ type loggerOptions struct {
 	brokers   []string
 	registers []string
 	stores    []string
-	meters    []string
-	tracers   []string
+	// meters    []string
+	tracers []string
 }
 
 /*
diff --git a/register/memory/memory_test.go b/register/memory/memory_test.go
index 8d2619ec..03928dcb 100644
--- a/register/memory/memory_test.go
+++ b/register/memory/memory_test.go
@@ -302,19 +302,17 @@ func TestWatcher(t *testing.T) {
 	}
 	defer wc.Stop()
 
+	cherr := make(chan error, 10)
 	var wg sync.WaitGroup
 	wg.Add(1)
 	go func() {
-		for {
-			_, err := wc.Next()
-			if err != nil {
-				t.Fatal("unexpected err", err)
-			}
-			// t.Logf("changes %#+v", ch.Service)
-			wc.Stop()
-			wg.Done()
-			return
+		_, err := wc.Next()
+		if err != nil {
+			cherr <- fmt.Errorf("unexpected err %v", err)
 		}
+		// t.Logf("changes %#+v", ch.Service)
+		wc.Stop()
+		wg.Done()
 	}()
 
 	if err := m.Register(ctx, testSrv); err != nil {
diff --git a/semconv/cache.go b/semconv/cache.go
new file mode 100644
index 00000000..d23d0cb5
--- /dev/null
+++ b/semconv/cache.go
@@ -0,0 +1,14 @@
+package semconv
+
+var (
+	// CacheRequestDurationSeconds specifies meter metric name
+	CacheRequestDurationSeconds = "micro_cache_request_duration_seconds"
+	// CacheRequestLatencyMicroseconds specifies meter metric name
+	CacheRequestLatencyMicroseconds = "micro_cache_request_latency_microseconds"
+	// CacheRequestTotal specifies meter metric name
+	CacheRequestTotal = "micro_cache_request_total"
+	// CacheRequestInflight specifies meter metric name
+	CacheRequestInflight = "micro_cache_request_inflight"
+	// CacheItemsTotal specifies total cache items
+	CacheItemsTotal = "micro_cache_items_total"
+)
diff --git a/semconv/store.go b/semconv/store.go
index a9044f48..f1f2e684 100644
--- a/semconv/store.go
+++ b/semconv/store.go
@@ -3,7 +3,7 @@ package semconv
 var (
 	// StoreRequestDurationSeconds specifies meter metric name
 	StoreRequestDurationSeconds = "micro_store_request_duration_seconds"
-	// ClientRequestLatencyMicroseconds specifies meter metric name
+	// StoreRequestLatencyMicroseconds specifies meter metric name
 	StoreRequestLatencyMicroseconds = "micro_store_request_latency_microseconds"
 	// StoreRequestTotal specifies meter metric name
 	StoreRequestTotal = "micro_store_request_total"
diff --git a/server/noop.go b/server/noop.go
index d19ffa17..d742706c 100644
--- a/server/noop.go
+++ b/server/noop.go
@@ -171,7 +171,6 @@ type rpcMessage struct {
 	header      metadata.Metadata
 	topic       string
 	contentType string
-	body        []byte
 }
 
 func (r *rpcMessage) ContentType() string {
diff --git a/service.go b/service.go
index cf661c44..b5b053f8 100644
--- a/service.go
+++ b/service.go
@@ -23,10 +23,8 @@ import (
 )
 
 func init() {
-	if _, err := maxprocs.Set(); err != nil {
-		panic(err)
-	}
-	if _, err := memlimit.SetGoMemLimitWithOpts(
+	_, _ = maxprocs.Set()
+	_, _ = memlimit.SetGoMemLimitWithOpts(
 		memlimit.WithRatio(0.9),
 		memlimit.WithProvider(
 			memlimit.ApplyFallback(
@@ -34,11 +32,12 @@ func init() {
 				memlimit.FromSystem,
 			),
 		),
-	); err != nil {
-		panic(err)
-	}
+	)
 
-	net.DefaultResolver = utildns.NewNetResolver(utildns.Timeout(1 * time.Second))
+	net.DefaultResolver = utildns.NewNetResolver(
+		utildns.Timeout(1*time.Second),
+		utildns.MinCacheTTL(5*time.Second),
+	)
 }
 
 // Service is an interface that wraps the lower level components.
diff --git a/store/store.go b/store/store.go
index 9c02d649..531a022c 100644
--- a/store/store.go
+++ b/store/store.go
@@ -105,3 +105,7 @@ func NewWatchOptions(opts ...WatchOption) (WatchOptions, error) {
 
 	return options, err
 }
+
+func Watch(context.Context) (Watcher, error) {
+	return nil, nil
+}
diff --git a/util/dns/cache.go b/util/dns/cache.go
index de184819..f9b06bde 100644
--- a/util/dns/cache.go
+++ b/util/dns/cache.go
@@ -6,6 +6,9 @@ import (
 	"net"
 	"sync"
 	"time"
+
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/semconv"
 )
 
 // DialFunc is a [net.Resolver.Dial] function.
@@ -19,6 +22,11 @@ func NewNetResolver(opts ...Option) *net.Resolver {
 		o(&options)
 	}
 
+	if options.Meter == nil {
+		options.Meter = meter.DefaultMeter
+		opts = append(opts, Meter(options.Meter))
+	}
+
 	return &net.Resolver{
 		PreferGo:     true,
 		StrictErrors: options.Resolver.StrictErrors,
@@ -56,6 +64,7 @@ type Options struct {
 	PreferIPV4      bool
 	PreferIPV6      bool
 	Timeout         time.Duration
+	Meter           meter.Meter
 }
 
 // MaxCacheEntries sets the maximum number of entries to cache.
@@ -87,6 +96,13 @@ func NegativeCache(b bool) Option {
 	}
 }
 
+// Meter sets meter.Meter
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
 // Timeout sets upstream *net.Resolver timeout
 func Timeout(td time.Duration) Option {
 	return func(o *Options) {
@@ -156,7 +172,6 @@ func (c *cache) put(req string, res string) {
 	}
 
 	c.Lock()
-	defer c.Unlock()
 	if c.entries == nil {
 		c.entries = make(map[string]cacheEntry)
 	}
@@ -165,6 +180,8 @@ func (c *cache) put(req string, res string) {
 	var tested, evicted int
 	for k, e := range c.entries {
 		if time.Until(e.deadline) <= 0 {
+			c.opts.Meter.Counter(semconv.CacheItemsTotal, "type", "dns").Dec()
+			c.opts.Meter.Counter(semconv.CacheRequestTotal, "type", "dns", "method", "evict").Inc()
 			// delete expired entry
 			delete(c.entries, k)
 			evicted++
@@ -175,6 +192,8 @@ func (c *cache) put(req string, res string) {
 			continue
 		}
 		if evicted == 0 && c.opts.MaxCacheEntries > 0 && len(c.entries) >= c.opts.MaxCacheEntries {
+			c.opts.Meter.Counter(semconv.CacheItemsTotal, "type", "dns").Dec()
+			c.opts.Meter.Counter(semconv.CacheRequestTotal, "type", "dns", "method", "evict").Inc()
 			// delete at least one entry
 			delete(c.entries, k)
 		}
@@ -186,6 +205,9 @@ func (c *cache) put(req string, res string) {
 		deadline: time.Now().Add(ttl),
 		value:    res[2:],
 	}
+
+	c.opts.Meter.Counter(semconv.CacheItemsTotal, "type", "dns").Inc()
+	c.Unlock()
 }
 
 func (c *cache) get(req string) (res string) {
@@ -210,6 +232,7 @@ func (c *cache) get(req string) (res string) {
 		// prepend correct ID
 		return req[:2] + entry.value
 	}
+
 	return ""
 }
 
@@ -310,10 +333,18 @@ func getUint32(s string) int {
 
 func cachingRoundTrip(cache *cache, network, address string) roundTripper {
 	return func(ctx context.Context, req string) (res string, err error) {
+		cache.opts.Meter.Counter(semconv.CacheRequestInflight, "type", "dns").Inc()
+		defer cache.opts.Meter.Counter(semconv.CacheRequestInflight, "type", "dns").Dec()
 		// check cache
 		if res = cache.get(req); res != "" {
 			return res, nil
 		}
+		cache.opts.Meter.Counter(semconv.CacheRequestTotal, "type", "dns", "method", "get", "status", "miss").Inc()
+		ts := time.Now()
+		defer func() {
+			cache.opts.Meter.Summary(semconv.CacheRequestLatencyMicroseconds, "type", "dns", "method", "get").UpdateDuration(ts)
+			cache.opts.Meter.Histogram(semconv.CacheRequestDurationSeconds, "type", "dns", "method", "get").UpdateDuration(ts)
+		}()
 
 		switch {
 		case cache.opts.PreferIPV4 && cache.opts.PreferIPV6:
@@ -340,6 +371,7 @@ func cachingRoundTrip(cache *cache, network, address string) roundTripper {
 			var d net.Dialer
 			conn, err = d.DialContext(ctx, network, address)
 		}
+
 		if err != nil {
 			return "", err
 		}
diff --git a/util/dns/cache_test.go b/util/dns/cache_test.go
index 6e2fb1d1..1c939145 100644
--- a/util/dns/cache_test.go
+++ b/util/dns/cache_test.go
@@ -12,5 +12,11 @@ func TestCache(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	t.Logf("addrs %v", addrs)
+
+	addrs, err = net.LookupHost("unistack.org")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = addrs
 }
diff --git a/util/dns/conn.go b/util/dns/conn.go
index e7e11eea..e8b5f426 100644
--- a/util/dns/conn.go
+++ b/util/dns/conn.go
@@ -67,15 +67,20 @@ func (c *dnsConn) RemoteAddr() net.Addr {
 }
 
 func (c *dnsConn) SetDeadline(t time.Time) error {
-	_ = c.SetReadDeadline(t)
-	_ = c.SetWriteDeadline(t)
+	var err error
+	if err = c.SetReadDeadline(t); err != nil {
+		return err
+	}
+	if err = c.SetWriteDeadline(t); err != nil {
+		return err
+	}
 	return nil
 }
 
 func (c *dnsConn) SetReadDeadline(t time.Time) error {
 	c.Lock()
-	defer c.Unlock()
 	c.deadline = t
+	c.Unlock()
 	return nil
 }
 
diff --git a/util/jitter/ticker.go b/util/jitter/ticker.go
index f4184899..b5b86f70 100644
--- a/util/jitter/ticker.go
+++ b/util/jitter/ticker.go
@@ -16,7 +16,6 @@ type Ticker struct {
 	C    chan time.Time
 	min  int64
 	max  int64
-	exp  int64
 	exit bool
 	rng  rand.Rand
 }
diff --git a/util/reflect/reflect.go b/util/reflect/reflect.go
index 729b4e02..859beb20 100644
--- a/util/reflect/reflect.go
+++ b/util/reflect/reflect.go
@@ -91,7 +91,7 @@ func Merge(dst interface{}, mp map[string]interface{}, opts ...Option) error {
 	}
 
 	if mapper, ok := dst.(map[string]interface{}); ok {
-		dst = mergeMap(mapper, mp, 0)
+		mergeMap(mapper, mp, 0)
 		return nil
 	}
 
diff --git a/util/reflect/reflect_test.go b/util/reflect/reflect_test.go
index ccb78e49..cbfc13fc 100644
--- a/util/reflect/reflect_test.go
+++ b/util/reflect/reflect_test.go
@@ -1,9 +1,38 @@
 package reflect
 
 import (
+	"fmt"
 	"testing"
 )
 
+func TestMergeMapStringInterface(t *testing.T) {
+	var dst interface{} //nolint:gosimple
+	dst = map[string]interface{}{
+		"xx": 11,
+	}
+
+	src := map[string]interface{}{
+		"zz": "aa",
+	}
+
+	if err := Merge(dst, src); err != nil {
+		t.Fatal(err)
+	}
+
+	mp, ok := dst.(map[string]interface{})
+	if !ok || mp == nil {
+		t.Fatalf("xxx %#+v\n", dst)
+	}
+
+	if fmt.Sprintf("%v", mp["xx"]) != "11" {
+		t.Fatalf("xxx zzzz %#+v", mp)
+	}
+
+	if fmt.Sprintf("%v", mp["zz"]) != "aa" {
+		t.Fatalf("xxx zzzz %#+v", mp)
+	}
+}
+
 func TestMergeMap(t *testing.T) {
 	src := map[string]interface{}{
 		"skey1": "sval1",
diff --git a/util/structfs/structfs.go b/util/structfs/structfs.go
index 462200db..3cffc750 100644
--- a/util/structfs/structfs.go
+++ b/util/structfs/structfs.go
@@ -221,6 +221,7 @@ func getValue(name string, iface interface{}, tag string) ([]byte, error) {
 	return nil, fmt.Errorf("failed to find %s in interface %T", name, iface)
 }
 
+/*
 func hasValidType(obj interface{}, types []reflect.Kind) bool {
 	for _, t := range types {
 		if reflect.TypeOf(obj).Kind() == t {
@@ -230,6 +231,7 @@ func hasValidType(obj interface{}, types []reflect.Kind) bool {
 
 	return false
 }
+*/
 
 func reflectValue(obj interface{}) reflect.Value {
 	var val reflect.Value
diff --git a/util/structfs/structfs_test.go b/util/structfs/structfs_test.go
index a245f3b1..ccf18bad 100644
--- a/util/structfs/structfs_test.go
+++ b/util/structfs/structfs_test.go
@@ -61,7 +61,7 @@ var doOrig = []byte(`{
 }
 `)
 
-func server(t *testing.T) {
+func server(t *testing.T, ch chan error) {
 	stfs := DigitalOceanMetadata{}
 	err := json.Unmarshal(doOrig, &stfs.Metadata.V1)
 	if err != nil {
@@ -71,7 +71,7 @@ func server(t *testing.T) {
 	http.Handle("/metadata/v1/", FileServer(&stfs, "json", time.Now()))
 	http.Handle("/metadata/v1.json", &stfs)
 	go func() {
-		t.Fatal(http.ListenAndServe("127.0.0.1:8080", nil))
+		ch <- http.ListenAndServe("127.0.0.1:8080", nil)
 	}()
 	time.Sleep(2 * time.Second)
 }
@@ -86,7 +86,8 @@ func get(path string) ([]byte, error) {
 }
 
 func TestAll(t *testing.T) {
-	server(t)
+	ch := make(chan error)
+	server(t, ch)
 
 	tests := []struct {
 		in  string
@@ -100,34 +101,44 @@ func TestAll(t *testing.T) {
 	}
 
 	for _, tt := range tests {
-		buf, err := get(tt.in)
+		select {
+		case err := <-ch:
+			t.Fatal(err)
+		default:
+			buf, err := get(tt.in)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if string(buf) != tt.out {
+				t.Errorf("req %s output %s not match requested %s", tt.in, string(buf), tt.out)
+			}
+		}
+	}
+
+	select {
+	case err := <-ch:
+		t.Fatal(err)
+	default:
+		doTest, err := get("http://127.0.0.1:8080/metadata/v1.json")
 		if err != nil {
 			t.Fatal(err)
 		}
-		if string(buf) != tt.out {
-			t.Errorf("req %s output %s not match requested %s", tt.in, string(buf), tt.out)
+
+		oSt := DigitalOceanMetadata{}
+		err = json.Unmarshal(doOrig, &oSt.Metadata.V1)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		nSt := DigitalOceanMetadata{}
+
+		err = json.Unmarshal(doTest, &nSt.Metadata.V1)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !reflect.DeepEqual(oSt, nSt) {
+			t.Fatalf("%v not match %v", oSt, nSt)
 		}
 	}
-
-	doTest, err := get("http://127.0.0.1:8080/metadata/v1.json")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	oSt := DigitalOceanMetadata{}
-	err = json.Unmarshal(doOrig, &oSt.Metadata.V1)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	nSt := DigitalOceanMetadata{}
-
-	err = json.Unmarshal(doTest, &nSt.Metadata.V1)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !reflect.DeepEqual(oSt, nSt) {
-		t.Fatalf("%v not match %v", oSt, nSt)
-	}
 }