Run golint and go vet (#276)

Cleanup the errors and removed deadcode along the way. The leaves
some error laying around, mostly about commenting exported identifier.
We should look hard if those really are needed.

17 files changed, 42 insertions, 33 deletions

diff --git a/middleware/cache/setup.go b/middleware/cache/setup.go
index 05811a276..c0b09024b 100644
--- a/middleware/cache/setup.go
+++ b/middleware/cache/setup.go
@@ -56,7 +56,7 @@ func cacheParse(c *caddy.Controller) (int, []string, error) {
 				}
 			}
 
-			for i, _ := range origins {
+			for i := range origins {
 				origins[i] = middleware.Host(origins[i]).Normalize()
 			}
 			return ttl, origins, nil
diff --git a/middleware/dnssec/responsewriter.go b/middleware/dnssec/responsewriter.go
index 0032fa7ba..95378c091 100644
--- a/middleware/dnssec/responsewriter.go
+++ b/middleware/dnssec/responsewriter.go
@@ -10,16 +10,16 @@ import (
 	"github.com/miekg/dns"
 )
 
-type DnssecResponseWriter struct {
+type ResponseWriter struct {
 	dns.ResponseWriter
 	d Dnssec
 }
 
-func NewDnssecResponseWriter(w dns.ResponseWriter, d Dnssec) *DnssecResponseWriter {
-	return &DnssecResponseWriter{w, d}
+func NewDnssecResponseWriter(w dns.ResponseWriter, d Dnssec) *ResponseWriter {
+	return &ResponseWriter{w, d}
 }
 
-func (d *DnssecResponseWriter) WriteMsg(res *dns.Msg) error {
+func (d *ResponseWriter) WriteMsg(res *dns.Msg) error {
 	// By definition we should sign anything that comes back, we should still figure out for
 	// which zone it should be.
 	state := request.Request{W: d.ResponseWriter, Req: res}
@@ -38,13 +38,13 @@ func (d *DnssecResponseWriter) WriteMsg(res *dns.Msg) error {
 	return d.ResponseWriter.WriteMsg(res)
 }
 
-func (d *DnssecResponseWriter) Write(buf []byte) (int, error) {
+func (d *ResponseWriter) Write(buf []byte) (int, error) {
 	log.Printf("[WARNING] Dnssec called with Write: not signing reply")
 	n, err := d.ResponseWriter.Write(buf)
 	return n, err
 }
 
-func (d *DnssecResponseWriter) Hijack() {
+func (d *ResponseWriter) Hijack() {
 	d.ResponseWriter.Hijack()
 	return
 }
diff --git a/middleware/file/reload_test.go b/middleware/file/reload_test.go
index 1ba9f4bcf..02d789c66 100644
--- a/middleware/file/reload_test.go
+++ b/middleware/file/reload_test.go
@@ -39,7 +39,7 @@ func TestZoneReload(t *testing.T) {
 		t.Fatalf("expected 5 RRs, got %d", len(z.All()))
 	}
 	if err := ioutil.WriteFile(fileName, []byte(reloadZone2Test), 0644); err != nil {
-		t.Fatalf("failed to write new zone data", err)
+		t.Fatalf("failed to write new zone data: %s", err)
 	}
 	// Could still be racy, but we need to wait a bit for the event to be seen
 	time.Sleep(1 * time.Second)
diff --git a/middleware/file/secondary.go b/middleware/file/secondary.go
index 9493a7fdd..ef44e124f 100644
--- a/middleware/file/secondary.go
+++ b/middleware/file/secondary.go
@@ -176,7 +176,6 @@ Restart:
 			}
 		}
 	}
-	return nil
 }
 
 // The maximum difference between two serial numbers. If the difference between
diff --git a/middleware/file/tree/less.go b/middleware/file/tree/less.go
index 32d87b683..595dc9213 100644
--- a/middleware/file/tree/less.go
+++ b/middleware/file/tree/less.go
@@ -39,7 +39,6 @@ func less(a, b string) int {
 		i++
 		aj, bj = ai, bi
 	}
-	return 0
 }
 
 func doDDD(b []byte) {
diff --git a/middleware/kubernetes/setup.go b/middleware/kubernetes/setup.go
index f976ba75b..dfa8c7ce4 100644
--- a/middleware/kubernetes/setup.go
+++ b/middleware/kubernetes/setup.go
@@ -107,7 +107,7 @@ func kubernetesParse(c *caddy.Controller) (Kubernetes, error) {
 					if len(args) != 0 {
 						k8s.ResyncPeriod, err = time.ParseDuration(args[0])
 						if err != nil {
-							err = errors.New(fmt.Sprintf("Unable to parse resync duration value. Value provided was '%v'. Example valid values: '15s', '5m', '1h'. Error was: %v", args[0], err))
+							err = fmt.Errorf("Unable to parse resync duration value. Value provided was '%v'. Example valid values: '15s', '5m', '1h'. Error was: %v", args[0], err)
 							return Kubernetes{}, err
 						}
 					} else {
@@ -119,7 +119,7 @@ func kubernetesParse(c *caddy.Controller) (Kubernetes, error) {
 						labelSelectorString := strings.Join(args, " ")
 						k8s.LabelSelector, err = unversionedapi.ParseToLabelSelector(labelSelectorString)
 						if err != nil {
-							err = errors.New(fmt.Sprintf("Unable to parse label selector. Value provided was '%v'. Error was: %v", labelSelectorString, err))
+							err = fmt.Errorf("Unable to parse label selector. Value provided was '%v'. Error was: %v", labelSelectorString, err)
 							return Kubernetes{}, err
 						}
 					} else {
diff --git a/middleware/kubernetes/subzone_test.go b/middleware/kubernetes/subzone_test.go
index c48e66c12..b1a9541b3 100644
--- a/middleware/kubernetes/subzone_test.go
+++ b/middleware/kubernetes/subzone_test.go
@@ -21,7 +21,7 @@ var examplesSubzoneConflict = map[string]bool{
 	"":        false,
 }
 
-func TestsubzoneConflict(t *testing.T) {
+func TestSubzoneConflict(t *testing.T) {
 	for z, expected := range examplesSubzoneConflict {
 		actual, conflicts := subzoneConflict(confZones, z)
 
diff --git a/middleware/metrics/metrics.go b/middleware/metrics/metrics.go
index 3a72bc3bb..a9d09c202 100644
--- a/middleware/metrics/metrics.go
+++ b/middleware/metrics/metrics.go
@@ -30,7 +30,7 @@ type Metrics struct {
 	Addr      string
 	ln        net.Listener
 	mux       *http.ServeMux
-	Once      sync.Once
+	Once      *sync.Once
 	ZoneNames []string
 }
 
diff --git a/middleware/metrics/setup.go b/middleware/metrics/setup.go
index eee886f00..077a809d5 100644
--- a/middleware/metrics/setup.go
+++ b/middleware/metrics/setup.go
@@ -47,7 +47,7 @@ func prometheusParse(c *caddy.Controller) (Metrics, error) {
 		}
 		met.ZoneNames = make([]string, len(c.ServerBlockKeys))
 		copy(met.ZoneNames, c.ServerBlockKeys)
-		for i, _ := range met.ZoneNames {
+		for i := range met.ZoneNames {
 			met.ZoneNames[i] = middleware.Host(met.ZoneNames[i]).Normalize()
 		}
 		args := c.RemainingArgs()
@@ -79,6 +79,6 @@ func prometheusParse(c *caddy.Controller) (Metrics, error) {
 	return met, err
 }
 
-var metricsOnce sync.Once
+var metricsOnce *sync.Once
 
 const addr = "localhost:9153"
diff --git a/middleware/normalize.go b/middleware/normalize.go
index e28ed96ea..2d153ba78 100644
--- a/middleware/normalize.go
+++ b/middleware/normalize.go
@@ -7,6 +7,7 @@ import (
 	"github.com/miekg/dns"
 )
 
+// Zones respresents a lists of zone names.
 type Zones []string
 
 // Matches checks is qname is a subdomain of any of the zones in z.  The match
@@ -27,7 +28,7 @@ func (z Zones) Matches(qname string) string {
 
 // Normalize fully qualifies all zones in z.
 func (z Zones) Normalize() {
-	for i, _ := range z {
+	for i := range z {
 		z[i] = Name(z[i]).Normalize()
 	}
 }
@@ -47,10 +48,11 @@ func (n Name) Matches(child string) bool {
 // Normalize lowercases and makes n fully qualified.
 func (n Name) Normalize() string { return strings.ToLower(dns.Fqdn(string(n))) }
 
-// Host represents a host from the Corefile, may contain port.
 type (
-	Host string
-	Addr string
+	// Host represents a host from the Corefile, may contain port.
+	Host string // Host represents a host from the Corefile, may contain port.
+	// Addr resprents an address in the Corefile.
+	Addr string // Addr resprents an address in the Corefile.
 )
 
 // Normalize will return the host portion of host, stripping
diff --git a/middleware/pkg/rcode/rcode.go b/middleware/pkg/rcode/rcode.go
index 006440071..e871a96ca 100644
--- a/middleware/pkg/rcode/rcode.go
+++ b/middleware/pkg/rcode/rcode.go
@@ -6,6 +6,8 @@ import (
 	"github.com/miekg/dns"
 )
 
+// ToString convert the rcode to the offical DNS string, or to "RCODE"+value if the RCODE
+// value is unknown.
 func ToString(rcode int) string {
 	if str, ok := dns.RcodeToString[rcode]; ok {
 		return str
diff --git a/middleware/pkg/response/classify.go b/middleware/pkg/response/classify.go
index adbaa6526..65055dff4 100644
--- a/middleware/pkg/response/classify.go
+++ b/middleware/pkg/response/classify.go
@@ -2,14 +2,20 @@ package response
 
 import "github.com/miekg/dns"
 
+// Type is the type of the message
 type Type int
 
 const (
-	Success    Type = iota
-	NameError       // NXDOMAIN in header, SOA in auth.
-	NoData          // NOERROR in header, SOA in auth.
-	Delegation      // NOERROR in header, NS in auth, optionally fluff in additional (not checked).
-	OtherError      // Don't cache these.
+	// Success indicates a positive reply
+	Success Type = iota
+	// NameError is a NXDOMAIN in header, SOA in auth.
+	NameError
+	// NoData indicated name found, but not the type: NOERROR in header, SOA in auth.
+	NoData
+	// Delegation is a msg with a pointer to another nameserver: NOERROR in header, NS in auth, optionally fluff in additional (not checked).
+	Delegation
+	// OtherError indicated any other error: don't cache these.
+	OtherError
 )
 
 // Classify classifies a message, it returns the Type.
diff --git a/middleware/pkg/storage/fs.go b/middleware/pkg/storage/fs.go
index 3ee14b7ed..4cbf526ae 100644
--- a/middleware/pkg/storage/fs.go
+++ b/middleware/pkg/storage/fs.go
@@ -25,7 +25,7 @@ type dir http.Dir
 //
 // CoreDir will default to "$HOME/.coredns" on Unix, but it's location can be overriden with the COREDNSPATH
 // environment variable.
-var CoreDir dir = dir(fsPath())
+var CoreDir = dir(fsPath())
 
 func (d dir) Zone(z string) dir {
 	if z != "." && z[len(z)-2] == '.' {
diff --git a/middleware/pkg/storage/fs_test.go b/middleware/pkg/storage/fs_test.go
index f7e8ccf9d..5692b580e 100644
--- a/middleware/pkg/storage/fs_test.go
+++ b/middleware/pkg/storage/fs_test.go
@@ -7,7 +7,7 @@ import (
 	"testing"
 )
 
-func TestfsPath(t *testing.T) {
+func TestFsPath(t *testing.T) {
 	if actual := fsPath(); !strings.HasSuffix(actual, ".coredns") {
 		t.Errorf("Expected path to be a .coredns folder, got: %v", actual)
 	}
diff --git a/middleware/pprof/pprof.go b/middleware/pprof/pprof.go
index f538b3091..cbef104d3 100644
--- a/middleware/pprof/pprof.go
+++ b/middleware/pprof/pprof.go
@@ -13,13 +13,14 @@ type Handler struct {
 }
 
 func (h *Handler) Startup() error {
-	if ln, err := net.Listen("tcp", addr); err != nil {
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
 		log.Printf("[ERROR] Failed to start pprof handler: %s", err)
 		return err
-	} else {
-		h.ln = ln
 	}
 
+	h.ln = ln
+
 	h.mux = http.NewServeMux()
 	h.mux.HandleFunc(path+"/", pp.Index)
 	h.mux.HandleFunc(path+"/cmdline", pp.Cmdline)
diff --git a/middleware/secondary/setup.go b/middleware/secondary/setup.go
index d0367094d..eb112faf9 100644
--- a/middleware/secondary/setup.go
+++ b/middleware/secondary/setup.go
@@ -56,7 +56,7 @@ func secondaryParse(c *caddy.Controller) (file.Zones, error) {
 			if len(args) > 0 {
 				origins = args
 			}
-			for i, _ := range origins {
+			for i := range origins {
 				origins[i] = middleware.Host(origins[i]).Normalize()
 				z[origins[i]] = file.NewZone(origins[i], "stdin")
 				names = append(names, origins[i])
diff --git a/middleware/test/helpers.go b/middleware/test/helpers.go
index 8ed27261f..37d046cb3 100644
--- a/middleware/test/helpers.go
+++ b/middleware/test/helpers.go
@@ -149,12 +149,12 @@ func Section(t *testing.T, tc Case, sect Sect, rr []dns.RR) bool {
 				return false
 			}
 			if x.SignerName != section[i].(*dns.RRSIG).SignerName {
-				t.Errorf("rr %d should have a SignerName of %d, but has %d", i, section[i].(*dns.RRSIG).SignerName, x.SignerName)
+				t.Errorf("rr %d should have a SignerName of %s, but has %s", i, section[i].(*dns.RRSIG).SignerName, x.SignerName)
 				return false
 			}
 		case *dns.NSEC:
 			if x.NextDomain != section[i].(*dns.NSEC).NextDomain {
-				t.Errorf("rr %d should have a NextDomain of %d, but has %d", i, section[i].(*dns.NSEC).NextDomain, x.NextDomain)
+				t.Errorf("rr %d should have a NextDomain of %s, but has %s", i, section[i].(*dns.NSEC).NextDomain, x.NextDomain)
 				return false
 			}
 			// TypeBitMap