all: gometalinter (#843)

* kubernetes/reverse: remove deadcode
* deadcode in errors and kubernetes removed
* unnecessary conversion
* constants
* proxy: time.Since()
* simplications
* static check
* Disable test/external_test

25 files changed, 105 insertions, 150 deletions

diff --git a/core/dnsserver/server.go b/core/dnsserver/server.go
index 61ef6ac65..fb8653c18 100644
--- a/core/dnsserver/server.go
+++ b/core/dnsserver/server.go
@@ -187,7 +187,8 @@ func (s *Server) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
 
 	q := r.Question[0].Name
 	b := make([]byte, len(q))
-	off, end := 0, false
+	var off int
+	var end bool
 
 	var dshandler *Config
 
diff --git a/middleware/auto/setup.go b/middleware/auto/setup.go
index 1f8fd3b6c..6bda11238 100644
--- a/middleware/auto/setup.go
+++ b/middleware/auto/setup.go
@@ -74,7 +74,7 @@ func setup(c *caddy.Controller) error {
 
 func autoParse(c *caddy.Controller) (Auto, error) {
 	var a = Auto{
-		loader: loader{template: "${1}", re: regexp.MustCompile(`db\.(.*)`), duration: time.Duration(60 * time.Second)},
+		loader: loader{template: "${1}", re: regexp.MustCompile(`db\.(.*)`), duration: 60 * time.Second},
 		Zones:  &Zones{},
 	}
 
diff --git a/middleware/backend_lookup.go b/middleware/backend_lookup.go
index 7621851c9..7ad011b98 100644
--- a/middleware/backend_lookup.go
+++ b/middleware/backend_lookup.go
@@ -218,7 +218,7 @@ func SRV(b ServiceBackend, zone string, state request.Request, opt Options) (rec
 			// Internal name, we should have some info on them, either v4 or v6
 			// Clients expect a complete answer, because we are a recursor in their view.
 			state1 := state.NewWithQuestion(srv.Target, dns.TypeA)
-			addr, debugAddr, e1 := A(b, zone, state1, nil, Options(opt))
+			addr, debugAddr, e1 := A(b, zone, state1, nil, opt)
 			if e1 == nil {
 				extra = append(extra, addr...)
 				debug = append(debug, debugAddr...)
diff --git a/middleware/dnssec/cache_test.go b/middleware/dnssec/cache_test.go
index b9434fcbe..7d42a90df 100644
--- a/middleware/dnssec/cache_test.go
+++ b/middleware/dnssec/cache_test.go
@@ -25,7 +25,7 @@ func TestCacheSet(t *testing.T) {
 	state := request.Request{Req: m}
 	k := hash(m.Answer) // calculate *before* we add the sig
 	d := New([]string{"miek.nl."}, []*DNSKEY{dnskey}, nil, c)
-	m = d.Sign(state, "miek.nl.", time.Now().UTC())
+	d.Sign(state, "miek.nl.", time.Now().UTC())
 
 	_, ok := d.get(k)
 	if !ok {
diff --git a/middleware/dnstap/handler.go b/middleware/dnstap/handler.go
index 20121ff2e..0cf281e69 100644
--- a/middleware/dnstap/handler.go
+++ b/middleware/dnstap/handler.go
@@ -2,9 +2,10 @@ package dnstap
 
 import (
 	"fmt"
-	"golang.org/x/net/context"
 	"io"
 
+	"golang.org/x/net/context"
+
 	"github.com/coredns/coredns/middleware"
 	"github.com/coredns/coredns/middleware/dnstap/msg"
 	"github.com/coredns/coredns/middleware/dnstap/taprw"
@@ -33,10 +34,10 @@ func (h Dnstap) TapMessage(m *tap.Message) error {
 }
 
 func (h Dnstap) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
-	rw := taprw.ResponseWriter{ResponseWriter: w, Taper: &h, Query: r, Pack: h.Pack}
+	rw := &taprw.ResponseWriter{ResponseWriter: w, Taper: &h, Query: r, Pack: h.Pack}
 	rw.QueryEpoch()
 
-	code, err := middleware.NextOrFailure(h.Name(), h.Next, ctx, &rw, r)
+	code, err := middleware.NextOrFailure(h.Name(), h.Next, ctx, rw, r)
 	if err != nil {
 		// ignore dnstap errors
 		return code, err
diff --git a/middleware/erratic/setup.go b/middleware/erratic/setup.go
index 714fc309b..cdfc3407d 100644
--- a/middleware/erratic/setup.go
+++ b/middleware/erratic/setup.go
@@ -65,7 +65,7 @@ func parseErratic(c *caddy.Controller) (*Erratic, error) {
 
 				// Defaults.
 				e.delay = 2
-				e.duration = time.Duration(100 * time.Millisecond)
+				e.duration = 100 * time.Millisecond
 				if len(args) == 0 {
 					continue
 				}
diff --git a/middleware/errors/errors.go b/middleware/errors/errors.go
index 057e65089..9b0bfa946 100644
--- a/middleware/errors/errors.go
+++ b/middleware/errors/errors.go
@@ -76,11 +76,4 @@ func (h errorHandler) recovery(ctx context.Context, w dns.ResponseWriter, r *dns
 	h.Log.Printf(panicMsg)
 }
 
-// debugMsg creates a debug message that gets send back to the client.
-func debugMsg(rcode int, r *dns.Msg) *dns.Msg {
-	answer := new(dns.Msg)
-	answer.SetRcode(r, rcode)
-	return answer
-}
-
 const timeFormat = "02/Jan/2006:15:04:05 -0700"
diff --git a/middleware/file/lookup.go b/middleware/file/lookup.go
index 2ca1ec943..89e0f5a47 100644
--- a/middleware/file/lookup.go
+++ b/middleware/file/lookup.go
@@ -231,7 +231,7 @@ func (z *Zone) Lookup(state request.Request, qname string) ([]dns.RR, []dns.RR,
 
 	ret := z.soa(do)
 	if do {
-		deny, found := z.Tree.Prev(qname)
+		deny, _ := z.Tree.Prev(qname) // TODO(miek): *found* was not used here.
 		nsec := z.typeFromElem(deny, dns.TypeNSEC, do)
 		ret = append(ret, nsec...)
 
diff --git a/middleware/file/notify.go b/middleware/file/notify.go
index e8f518d25..b1628c3a6 100644
--- a/middleware/file/notify.go
+++ b/middleware/file/notify.go
@@ -61,12 +61,12 @@ func notify(zone string, to []string) error {
 	return nil
 }
 
-func notifyAddr(c *dns.Client, m *dns.Msg, s string) (err error) {
-	ret := new(dns.Msg)
+func notifyAddr(c *dns.Client, m *dns.Msg, s string) error {
+	var err error
 
 	code := dns.RcodeServerFailure
 	for i := 0; i < 3; i++ {
-		ret, _, err = c.Exchange(m, s)
+		ret, _, err := c.Exchange(m, s)
 		if err != nil {
 			continue
 		}
diff --git a/middleware/kubernetes/controller.go b/middleware/kubernetes/controller.go
index 29562c0a7..3d60718ee 100644
--- a/middleware/kubernetes/controller.go
+++ b/middleware/kubernetes/controller.go
@@ -51,11 +51,10 @@ type dnsControl struct {
 
 	selector *labels.Selector
 
-	svcController  *cache.Controller
-	podController  *cache.Controller
-	nsController   *cache.Controller
-	epController   *cache.Controller
-	nodeController *cache.Controller
+	svcController *cache.Controller
+	podController *cache.Controller
+	nsController  *cache.Controller
+	epController  *cache.Controller
 
 	svcLister cache.StoreToServiceLister
 	podLister cache.StoreToPodLister
diff --git a/middleware/kubernetes/handler_test.go b/middleware/kubernetes/handler_test.go
index 9e38bc59f..04d64722f 100644
--- a/middleware/kubernetes/handler_test.go
+++ b/middleware/kubernetes/handler_test.go
@@ -273,32 +273,32 @@ func TestServeDNS(t *testing.T) {
 	k.Next = testHandler(nextMWMap)
 
 	ctx := context.TODO()
-	runServeDNSTests(t, dnsTestCases, k, ctx)
-	runServeDNSTests(t, autopathCases, k, ctx)
-	runServeDNSTests(t, autopathBareSearch, k, ctx)
+	runServeDNSTests(ctx, t, dnsTestCases, k)
+	runServeDNSTests(ctx, t, autopathCases, k)
+	runServeDNSTests(ctx, t, autopathBareSearch, k)
 
 	//Set PodMode to Disabled
 	k.PodMode = PodModeDisabled
-	runServeDNSTests(t, podModeDisabledCases, k, ctx)
+	runServeDNSTests(ctx, t, podModeDisabledCases, k)
 	//Set PodMode to Insecure
 	k.PodMode = PodModeInsecure
-	runServeDNSTests(t, podModeInsecureCases, k, ctx)
+	runServeDNSTests(ctx, t, podModeInsecureCases, k)
 	//Set PodMode to Verified
 	k.PodMode = PodModeVerified
-	runServeDNSTests(t, podModeVerifiedCases, k, ctx)
+	runServeDNSTests(ctx, t, podModeVerifiedCases, k)
 
 	// Set ndots to 2 for the ndots test cases
 	k.AutoPath.NDots = 2
-	runServeDNSTests(t, autopath2NDotsCases, k, ctx)
+	runServeDNSTests(ctx, t, autopath2NDotsCases, k)
 	k.AutoPath.NDots = defautNdots
 	// Disable the NXDOMAIN override (enabled by default)
 	k.OnNXDOMAIN = dns.RcodeNameError
-	runServeDNSTests(t, autopathCases, k, ctx)
-	runServeDNSTests(t, autopathBareSearchExpectNameErr, k, ctx)
+	runServeDNSTests(ctx, t, autopathCases, k)
+	runServeDNSTests(ctx, t, autopathBareSearchExpectNameErr, k)
 
 }
 
-func runServeDNSTests(t *testing.T, dnsTestCases map[string](*test.Case), k Kubernetes, ctx context.Context) {
+func runServeDNSTests(ctx context.Context, t *testing.T, dnsTestCases map[string](*test.Case), k Kubernetes) {
 	for testname, tc := range dnsTestCases {
 		testname = "\nTest Case \"" + testname + "\""
 		r := tc.Msg()
diff --git a/middleware/kubernetes/kubernetes.go b/middleware/kubernetes/kubernetes.go
index 016cfc403..3649eb02c 100644
--- a/middleware/kubernetes/kubernetes.go
+++ b/middleware/kubernetes/kubernetes.go
@@ -100,13 +100,12 @@ type recordRequest struct {
 }
 
 var (
-	errNoItems           = errors.New("no items found")
-	errNsNotExposed      = errors.New("namespace is not exposed")
-	errInvalidRequest    = errors.New("invalid query name")
-	errZoneNotFound      = errors.New("zone not found")
-	errAPIBadPodType     = errors.New("expected type *api.Pod")
-	errPodsDisabled      = errors.New("pod records disabled")
-	errResolvConfReadErr = errors.New("resolv.conf read error")
+	errNoItems        = errors.New("no items found")
+	errNsNotExposed   = errors.New("namespace is not exposed")
+	errInvalidRequest = errors.New("invalid query name")
+	errZoneNotFound   = errors.New("zone not found")
+	errAPIBadPodType  = errors.New("expected type *api.Pod")
+	errPodsDisabled   = errors.New("pod records disabled")
 )
 
 // Services implements the ServiceBackend interface.
@@ -468,13 +467,6 @@ func (k *Kubernetes) getRecordsForK8sItems(services []service, pods []pod, r rec
 	return records
 }
 
-func ipFromPodName(podname string) string {
-	if strings.Count(podname, "-") == 3 && !strings.Contains(podname, "--") {
-		return strings.Replace(podname, "-", ".", -1)
-	}
-	return strings.Replace(podname, "-", ":", -1)
-}
-
 func (k *Kubernetes) findPodWithIP(ip string) (p *api.Pod) {
 	if !k.AutoPath.Enabled {
 		return nil
diff --git a/middleware/kubernetes/kubernetes_test.go b/middleware/kubernetes/kubernetes_test.go
index 268028c1e..ae3fbf149 100644
--- a/middleware/kubernetes/kubernetes_test.go
+++ b/middleware/kubernetes/kubernetes_test.go
@@ -260,23 +260,6 @@ func TestEndpointHostname(t *testing.T) {
 	}
 }
 
-func TestIpFromPodName(t *testing.T) {
-	var tests = []struct {
-		ip       string
-		expected string
-	}{
-		{"10-11-12-13", "10.11.12.13"},
-		{"1-2-3-4", "1.2.3.4"},
-		{"1-2-3--A-B-C", "1:2:3::A:B:C"},
-	}
-	for _, test := range tests {
-		result := ipFromPodName(test.ip)
-		if result != test.expected {
-			t.Errorf("Expected ip for podname '%v' to be '%v', but got '%v'", test.ip, test.expected, result)
-		}
-	}
-}
-
 type APIConnServiceTest struct{}
 
 func (APIConnServiceTest) Run()                          { return }
diff --git a/middleware/kubernetes/setup.go b/middleware/kubernetes/setup.go
index a12673a13..d56b788f9 100644
--- a/middleware/kubernetes/setup.go
+++ b/middleware/kubernetes/setup.go
@@ -242,7 +242,6 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 
 const (
 	defaultResyncPeriod   = 5 * time.Minute
-	defaultPodMode        = PodModeDisabled
 	defautNdots           = 0
 	defaultResolvConfFile = "/etc/resolv.conf"
 	defaultOnNXDOMAIN     = dns.RcodeSuccess
diff --git a/middleware/kubernetes/setup_test.go b/middleware/kubernetes/setup_test.go
index c8e84a724..9512c8fbf 100644
--- a/middleware/kubernetes/setup_test.go
+++ b/middleware/kubernetes/setup_test.go
@@ -54,7 +54,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -70,7 +70,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -87,7 +87,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -105,7 +105,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -123,7 +123,7 @@ func TestKubernetesParse(t *testing.T) {
 			1,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -141,7 +141,7 @@ func TestKubernetesParse(t *testing.T) {
 			2,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -159,7 +159,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			30 * time.Second,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -177,7 +177,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			15 * time.Minute,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -195,7 +195,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"environment=prod",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -213,7 +213,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"application=nginx,environment in (production,qa,staging)",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -235,7 +235,7 @@ func TestKubernetesParse(t *testing.T) {
 			2,
 			15 * time.Minute,
 			"application=nginx,environment in (production,qa,staging)",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			true,
 			nil,
@@ -252,7 +252,7 @@ func TestKubernetesParse(t *testing.T) {
 			-1,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -268,7 +268,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -286,7 +286,7 @@ func TestKubernetesParse(t *testing.T) {
 			-1,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -304,7 +304,7 @@ func TestKubernetesParse(t *testing.T) {
 			-1,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -322,7 +322,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			0 * time.Minute,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -340,7 +340,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			0 * time.Second,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -358,7 +358,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			0 * time.Second,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -376,7 +376,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			0 * time.Second,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -394,7 +394,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			0 * time.Second,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -489,7 +489,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			[]net.IPNet{parseCidr("10.0.0.0/24"), parseCidr("10.0.1.0/24")},
 			false,
 			nil,
@@ -508,7 +508,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -527,7 +527,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -546,7 +546,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			[]string{"13.14.15.16:53"},
@@ -565,7 +565,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -585,7 +585,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -607,7 +607,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -626,7 +626,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -650,7 +650,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -668,7 +668,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -686,7 +686,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
@@ -704,7 +704,7 @@ func TestKubernetesParse(t *testing.T) {
 			0,
 			defaultResyncPeriod,
 			"",
-			defaultPodMode,
+			PodModeDisabled,
 			nil,
 			false,
 			nil,
diff --git a/middleware/metrics/test/scrape.go b/middleware/metrics/test/scrape.go
index c748be209..a21c0061d 100644
--- a/middleware/metrics/test/scrape.go
+++ b/middleware/metrics/test/scrape.go
@@ -69,7 +69,7 @@ type (
 func Scrape(t *testing.T, url string) []*MetricFamily {
 	mfChan := make(chan *dto.MetricFamily, 1024)
 
-	go fetchMetricFamilies(t, url, mfChan)
+	go fetchMetricFamilies(url, mfChan)
 
 	result := []*MetricFamily{}
 	for mf := range mfChan {
@@ -177,20 +177,20 @@ func makeBuckets(m *dto.Metric) map[string]string {
 	return result
 }
 
-func fetchMetricFamilies(t *testing.T, url string, ch chan<- *dto.MetricFamily) {
+func fetchMetricFamilies(url string, ch chan<- *dto.MetricFamily) {
 	defer close(ch)
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
-		t.Fatalf("creating GET request for URL %q failed: %s", url, err)
+		return
 	}
 	req.Header.Add("Accept", acceptHeader)
 	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
-		t.Fatalf("executing GET request for URL %q failed: %s", url, err)
+		return
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("GET request for URL %q returned HTTP status %s", url, resp.Status)
+		return
 	}
 
 	mediatype, params, err := mime.ParseMediaType(resp.Header.Get("Content-Type"))
@@ -203,7 +203,7 @@ func fetchMetricFamilies(t *testing.T, url string, ch chan<- *dto.MetricFamily)
 				if err == io.EOF {
 					break
 				}
-				t.Fatalf("reading metric family protocol buffer failed: %s", err)
+				return
 			}
 			ch <- mf
 		}
@@ -214,7 +214,7 @@ func fetchMetricFamilies(t *testing.T, url string, ch chan<- *dto.MetricFamily)
 		var parser expfmt.TextParser
 		metricFamilies, err := parser.TextToMetricFamilies(resp.Body)
 		if err != nil {
-			t.Fatal("reading text format failed:", err)
+			return
 		}
 		for _, mf := range metricFamilies {
 			ch <- mf
diff --git a/middleware/pkg/replacer/replacer.go b/middleware/pkg/replacer/replacer.go
index 5227808ae..5f5e15cd7 100644
--- a/middleware/pkg/replacer/replacer.go
+++ b/middleware/pkg/replacer/replacer.go
@@ -60,7 +60,7 @@ func New(r *dns.Msg, rr *dnsrecorder.Recorder, emptyValue string) Replacer {
 
 	// Header placeholders (case-insensitive)
 	rep.replacements[headerReplacer+"id}"] = strconv.Itoa(int(r.Id))
-	rep.replacements[headerReplacer+"opcode}"] = strconv.Itoa(int(r.Opcode))
+	rep.replacements[headerReplacer+"opcode}"] = strconv.Itoa(r.Opcode)
 	rep.replacements[headerReplacer+"do}"] = boolToString(req.Do())
 	rep.replacements[headerReplacer+"bufsize}"] = strconv.Itoa(req.Size())
 
diff --git a/middleware/proxy/lookup.go b/middleware/proxy/lookup.go
index fa6d1ddf2..a6c714f39 100644
--- a/middleware/proxy/lookup.go
+++ b/middleware/proxy/lookup.go
@@ -97,7 +97,7 @@ func (p Proxy) lookup(state request.Request) (*dns.Msg, error) {
 
 		// Since Select() should give us "up" hosts, keep retrying
 		// hosts until timeout (or until we get a nil host).
-		for time.Now().Sub(start) < tryDuration {
+		for time.Since(start) < tryDuration {
 			host := upstream.Select()
 			if host == nil {
 				return nil, errUnreachable
diff --git a/middleware/proxy/proxy.go b/middleware/proxy/proxy.go
index 4a574982d..8780330ed 100644
--- a/middleware/proxy/proxy.go
+++ b/middleware/proxy/proxy.go
@@ -109,7 +109,7 @@ func (p Proxy) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (
 
 		// Since Select() should give us "up" hosts, keep retrying
 		// hosts until timeout (or until we get a nil host).
-		for time.Now().Sub(start) < tryDuration {
+		for time.Since(start) < tryDuration {
 			host := upstream.Select()
 			if host == nil {
 
diff --git a/middleware/reverse/network.go b/middleware/reverse/network.go
index da3cb613b..80d533382 100644
--- a/middleware/reverse/network.go
+++ b/middleware/reverse/network.go
@@ -74,25 +74,6 @@ func (network *network) ipToHostname(ip net.IP) (name string) {
 	return strings.Replace(network.Template, templateNameIP, name, 1)
 }
 
-// just the same from net.ip package, but with uint8
-func uitoa(val uint8) string {
-	if val == 0 {
-		// avoid string allocation
-		return "0"
-	}
-	var buf [20]byte // big enough for 64bit value base 10
-	i := len(buf) - 1
-	for val >= 10 {
-		q := val / 10
-		buf[i] = byte('0' + val - q*10)
-		i--
-		val = q
-	}
-	// val < 10
-	buf[i] = byte('0' + val)
-	return string(buf[i:])
-}
-
 type networks []network
 
 func (n networks) Len() int      { return len(n) }
diff --git a/middleware/rewrite/edns0.go b/middleware/rewrite/edns0.go
index 1a0685312..913299a14 100644
--- a/middleware/rewrite/edns0.go
+++ b/middleware/rewrite/edns0.go
@@ -37,20 +37,21 @@ func (rule *edns0NsidRule) Rewrite(r *dns.Msg) Result {
 	result := RewriteIgnored
 	o := setupEdns0Opt(r)
 	found := false
+Option:
 	for _, s := range o.Option {
 		switch e := s.(type) {
 		case *dns.EDNS0_NSID:
-			if rule.action == "replace" || rule.action == "set" {
+			if rule.action == Replace || rule.action == Set {
 				e.Nsid = "" // make sure it is empty for request
 				result = RewriteDone
 			}
 			found = true
-			break
+			break Option
 		}
 	}
 
 	// add option if not found
-	if !found && (rule.action == "append" || rule.action == "set") {
+	if !found && (rule.action == Append || rule.action == Set) {
 		o.SetDo(true)
 		o.Option = append(o.Option, &dns.EDNS0_NSID{Code: dns.EDNS0NSID, Nsid: ""})
 		result = RewriteDone
@@ -68,7 +69,7 @@ func (rule *edns0LocalRule) Rewrite(r *dns.Msg) Result {
 		switch e := s.(type) {
 		case *dns.EDNS0_LOCAL:
 			if rule.code == e.Code {
-				if rule.action == "replace" || rule.action == "set" {
+				if rule.action == Replace || rule.action == Set {
 					e.Data = rule.data
 					result = RewriteDone
 				}
@@ -79,7 +80,7 @@ func (rule *edns0LocalRule) Rewrite(r *dns.Msg) Result {
 	}
 
 	// add option if not found
-	if !found && (rule.action == "append" || rule.action == "set") {
+	if !found && (rule.action == Append || rule.action == Set) {
 		o.SetDo(true)
 		var opt dns.EDNS0_LOCAL
 		opt.Code = rule.code
@@ -100,9 +101,9 @@ func newEdns0Rule(args ...string) (Rule, error) {
 	ruleType := strings.ToLower(args[0])
 	action := strings.ToLower(args[1])
 	switch action {
-	case "append":
-	case "replace":
-	case "set":
+	case Append:
+	case Replace:
+	case Set:
 	default:
 		return nil, fmt.Errorf("invalid action: %q", action)
 	}
@@ -139,3 +140,10 @@ func newEdns0LocalRule(action, code, data string) (*edns0LocalRule, error) {
 
 	return &edns0LocalRule{action: action, code: uint16(c), data: decoded}, nil
 }
+
+// These are all defined actions.
+const (
+	Replace = "replace"
+	Set     = "set"
+	Append  = "append"
+)
diff --git a/middleware/trace/setup.go b/middleware/trace/setup.go
index a6eb8c340..601472fee 100644
--- a/middleware/trace/setup.go
+++ b/middleware/trace/setup.go
@@ -97,7 +97,7 @@ func traceParse(c *caddy.Controller) (*trace, error) {
 func normalizeEndpoint(epType, ep string) (string, error) {
 	switch epType {
 	case "zipkin":
-		if strings.Index(ep, "http") == -1 {
+		if !strings.Contains(ep, "http") {
 			ep = "http://" + ep + "/api/v1/spans"
 		}
 		return ep, nil
diff --git a/middleware/trace/trace.go b/middleware/trace/trace.go
index 39b7d6750..86561871a 100644
--- a/middleware/trace/trace.go
+++ b/middleware/trace/trace.go
@@ -56,10 +56,8 @@ func (t *trace) setupZipkin() error {
 
 	recorder := zipkin.NewRecorder(collector, false, t.ServiceEndpoint, t.serviceName)
 	t.tracer, err = zipkin.NewTracer(recorder, zipkin.ClientServerSameSpan(t.clientServer))
-	if err != nil {
-		return err
-	}
-	return nil
+
+	return err
 }
 
 // Name implements the Handler interface.
diff --git a/request/request.go b/request/request.go
index d371d9c21..00a05b072 100644
--- a/request/request.go
+++ b/request/request.go
@@ -118,7 +118,7 @@ func (r *Request) Size() int {
 
 	size := 0
 	if o := r.Req.IsEdns0(); o != nil {
-		if o.Do() == true {
+		if o.Do() {
 			r.do = doTrue
 		} else {
 			r.do = doFalse
diff --git a/test/external_test.go b/test/external_test.go
index e5827a49c..9109f1f29 100644
--- a/test/external_test.go
+++ b/test/external_test.go
@@ -11,10 +11,12 @@ import (
 // Go get external example middleware, compile it into CoreDNS
 // and check if it is really there, but running coredns -plugins.
 
-func TestExternalMiddlewareCompile(t *testing.T) {
+// Dangerous test as it messes with your git tree, maybe use tag?
+func testExternalMiddlewareCompile(t *testing.T) {
 	if err := addExampleMiddleware(); err != nil {
 		t.Fatal(err)
 	}
+	defer run(t, gitReset)
 
 	if _, err := run(t, goGet); err != nil {
 		t.Fatal(err)
@@ -56,17 +58,15 @@ func addExampleMiddleware() error {
 	defer f.Close()
 
 	_, err = f.WriteString(example)
-	if err != nil {
-		return err
-	}
-	return nil
+	return err
 }
 
 var (
-	goBuild = exec.Command("go", "build")
-	goGen   = exec.Command("go", "generate")
-	goGet   = exec.Command("go", "get", "github.com/coredns/example")
-	coredns = exec.Command("./coredns", "-plugins")
+	goBuild  = exec.Command("go", "build")
+	goGen    = exec.Command("go", "generate")
+	goGet    = exec.Command("go", "get", "github.com/coredns/example")
+	gitReset = exec.Command("git", "checkout", "core/*")
+	coredns  = exec.Command("./coredns", "-plugins")
 )
 
 const example = "1001:example:github.com/coredns/example"