cleanup: go vet and golint run (#736)

* cleanup: go vet and golint run

Various cleanups trickered by go vet and golint.

* Fix tests and lowercase all errors

Lowercase all errors, some tests in kubernetes use errors from
kubernetes which do start with a capital letter.

core/dnsserver/server-grpc.go

@@ -16,8 +16,8 @@ import (
 	"github.com/coredns/coredns/pb"
 )
 
-// servergRPC represents an instance of a DNS-over-gRPC server.
-type servergRPC struct {
+// ServergRPC represents an instance of a DNS-over-gRPC server.
+type ServergRPC struct {
 	*Server
 	grpcServer *grpc.Server
 
@@ -25,18 +25,18 @@ type servergRPC struct {
 }
 
 // NewServergRPC returns a new CoreDNS GRPC server and compiles all middleware in to it.
-func NewServergRPC(addr string, group []*Config) (*servergRPC, error) {
+func NewServergRPC(addr string, group []*Config) (*ServergRPC, error) {
 
 	s, err := NewServer(addr, group)
 	if err != nil {
 		return nil, err
 	}
-	gs := &servergRPC{Server: s}
+	gs := &ServergRPC{Server: s}
 	return gs, nil
 }
 
 // Serve implements caddy.TCPServer interface.
-func (s *servergRPC) Serve(l net.Listener) error {
+func (s *ServergRPC) Serve(l net.Listener) error {
 	s.m.Lock()
 	s.listenAddr = l.Addr()
 	s.m.Unlock()
@@ -57,10 +57,10 @@ func (s *servergRPC) Serve(l net.Listener) error {
 }
 
 // ServePacket implements caddy.UDPServer interface.
-func (s *servergRPC) ServePacket(p net.PacketConn) error { return nil }
+func (s *ServergRPC) ServePacket(p net.PacketConn) error { return nil }
 
 // Listen implements caddy.TCPServer interface.
-func (s *servergRPC) Listen() (net.Listener, error) {
+func (s *ServergRPC) Listen() (net.Listener, error) {
 
 	// The *tls* middleware must make sure that multiple conflicting
 	// TLS configuration return an error: it can only be specified once.
@@ -88,11 +88,11 @@ func (s *servergRPC) Listen() (net.Listener, error) {
 }
 
 // ListenPacket implements caddy.UDPServer interface.
-func (s *servergRPC) ListenPacket() (net.PacketConn, error) { return nil, nil }
+func (s *ServergRPC) ListenPacket() (net.PacketConn, error) { return nil, nil }
 
 // OnStartupComplete lists the sites served by this server
 // and any relevant information, assuming Quiet is false.
-func (s *servergRPC) OnStartupComplete() {
+func (s *ServergRPC) OnStartupComplete() {
 	if Quiet {
 		return
 	}
@@ -102,7 +102,7 @@ func (s *servergRPC) OnStartupComplete() {
 	}
 }
 
-func (s *servergRPC) Stop() (err error) {
+func (s *ServergRPC) Stop() (err error) {
 	s.m.Lock()
 	defer s.m.Unlock()
 	if s.grpcServer != nil {
@@ -114,7 +114,7 @@ func (s *servergRPC) Stop() (err error) {
 // Query is the main entry-point into the gRPC server. From here we call ServeDNS like
 // any normal server. We use a custom responseWriter to pick up the bytes we need to write
 // back to the client as a protobuf.
-func (s *servergRPC) Query(ctx context.Context, in *pb.DnsPacket) (*pb.DnsPacket, error) {
+func (s *ServergRPC) Query(ctx context.Context, in *pb.DnsPacket) (*pb.DnsPacket, error) {
 	msg := new(dns.Msg)
 	err := msg.Unpack(in.Msg)
 	if err != nil {
@@ -144,7 +144,7 @@ func (s *servergRPC) Query(ctx context.Context, in *pb.DnsPacket) (*pb.DnsPacket
 	return &pb.DnsPacket{Msg: packed}, nil
 }
 
-func (s *servergRPC) Shutdown() error {
+func (s *ServergRPC) Shutdown() error {
 	if s.grpcServer != nil {
 		s.grpcServer.Stop()
 	}

middleware/cache/freq/freq.go

@@ -7,6 +7,7 @@ import (
 	"time"
 )
 
+// Freq tracks the frequence of things.
 type Freq struct {
 	// Last time we saw a query for this element.
 	last time.Time
@@ -21,7 +22,7 @@ func New(t time.Time) *Freq {
 	return &Freq{last: t, hits: 0}
 }
 
-// Updates updates the number of hits. Last time seen will be set to now.
+// Update updates the number of hits. Last time seen will be set to now.
 // If the last time we've seen this entity is within now - d, we increment hits, otherwise
 // we reset hits to 1. It returns the number of hits.
 func (f *Freq) Update(d time.Duration, now time.Time) int {

middleware/debug/debug_test.go

@@ -43,7 +43,7 @@ func TestDebug(t *testing.T) {
 			}
 		}
 		if cfg.Debug != test.expectedDebug {
-			t.Fatalf("Test %d: Expected debug to be: %t, but got: %t, input: %s", i, test.expectedDebug, test.input)
+			t.Fatalf("Test %d: Expected debug to be: %t, but got: %t, input: %s", i, test.expectedDebug, cfg.Debug, test.input)
 		}
 	}
 }

middleware/file/notify.go

@@ -71,7 +71,7 @@ func notifyAddr(c *dns.Client, m *dns.Msg, s string) (err error) {
 		}
 	}
 	if err != nil {
-		return fmt.Errorf("Notify for zone %q was not accepted by %q: %q", m.Question[0].Name, s, err)
+		return fmt.Errorf("notify for zone %q was not accepted by %q: %q", m.Question[0].Name, s, err)
 	}
-	return fmt.Errorf("Notify for zone %q was not accepted by %q: rcode was %q", m.Question[0].Name, s, rcode.ToString(code))
+	return fmt.Errorf("notify for zone %q was not accepted by %q: rcode was %q", m.Question[0].Name, s, rcode.ToString(code))
 }

middleware/file/reload.go

@@ -60,7 +60,7 @@ func (z *Zone) Reload() error {
 	return nil
 }
 
-// SOASerialIfDefind returns the SOA's serial if the zone has a SOA record in the Apex, or
+// SOASerialIfDefined returns the SOA's serial if the zone has a SOA record in the Apex, or
 // -1 otherwise.
 func (z *Zone) SOASerialIfDefined() int64 {
 	z.reloadMu.Lock()

middleware/kubernetes/federation.go

@@ -7,6 +7,7 @@ import (
 	"github.com/coredns/coredns/middleware/etcd/msg"
 )
 
+// Federation holds TODO(...).
 type Federation struct {
 	name string
 	zone string
@@ -26,8 +27,8 @@ const (
 	//
 	// But importing above breaks coredns with flag collision of 'log_dir'
 
-	LabelAvailabilityZone = "failure-domain.beta.kubernetes.io/zone"
-	LabelRegion           = "failure-domain.beta.kubernetes.io/region"
+	labelAvailabilityZone = "failure-domain.beta.kubernetes.io/zone"
+	labelRegion           = "failure-domain.beta.kubernetes.io/region"
 )
 
 // stripFederation removes the federation segment from the segment list, if it
@@ -66,12 +67,12 @@ func (k *Kubernetes) federationCNAMERecord(r recordRequest) msg.Service {
 		if r.endpoint == "" {
 			return msg.Service{
 				Key:  strings.Join([]string{msg.Path(r.zone, "coredns"), r.typeName, r.federation, r.namespace, r.service}, "/"),
-				Host: strings.Join([]string{r.service, r.namespace, r.federation, r.typeName, node.Labels[LabelAvailabilityZone], node.Labels[LabelRegion], f.zone}, "."),
+				Host: strings.Join([]string{r.service, r.namespace, r.federation, r.typeName, node.Labels[labelAvailabilityZone], node.Labels[labelRegion], f.zone}, "."),
 			}
 		}
 		return msg.Service{
 			Key:  strings.Join([]string{msg.Path(r.zone, "coredns"), r.typeName, r.federation, r.namespace, r.service, r.endpoint}, "/"),
-			Host: strings.Join([]string{r.endpoint, r.service, r.namespace, r.federation, r.typeName, node.Labels[LabelAvailabilityZone], node.Labels[LabelRegion], f.zone}, "."),
+			Host: strings.Join([]string{r.endpoint, r.service, r.namespace, r.federation, r.typeName, node.Labels[labelAvailabilityZone], node.Labels[labelRegion], f.zone}, "."),
 		}
 	}
 

middleware/kubernetes/federation_test.go

@@ -66,8 +66,8 @@ func (apiConnFedTest) GetNodeByName(name string) (api.Node, error) {
 		ObjectMeta: api.ObjectMeta{
 			Name: "test.node.foo.bar",
 			Labels: map[string]string{
-				LabelRegion:           "fd-r",
-				LabelAvailabilityZone: "fd-az",
+				labelRegion:           "fd-r",
+				labelAvailabilityZone: "fd-az",
 			},
 		},
 	}, nil

middleware/kubernetes/kubernetes.go

@@ -230,7 +230,7 @@ func (k *Kubernetes) InitKubeCache() (err error) {
 
 	kubeClient, err := kubernetes.NewForConfig(config)
 	if err != nil {
-		return fmt.Errorf("Failed to create kubernetes notification controller: %v", err)
+		return fmt.Errorf("failed to create kubernetes notification controller: %v", err)
 	}
 
 	if k.LabelSelector != nil {
@@ -238,7 +238,7 @@ func (k *Kubernetes) InitKubeCache() (err error) {
 		selector, err = unversionedapi.LabelSelectorAsSelector(k.LabelSelector)
 		k.Selector = &selector
 		if err != nil {
-			return fmt.Errorf("Unable to create Selector for LabelSelector '%s'.Error was: %s", k.LabelSelector, err)
+			return fmt.Errorf("unable to create Selector for LabelSelector '%s'.Error was: %s", k.LabelSelector, err)
 		}
 	}
 

middleware/kubernetes/kubernetes_test.go

@@ -431,8 +431,8 @@ func (APIConnServiceTest) GetNodeByName(name string) (api.Node, error) {
 		ObjectMeta: api.ObjectMeta{
 			Name: "test.node.foo.bar",
 			Labels: map[string]string{
-				LabelRegion:           "fd-r",
-				LabelAvailabilityZone: "fd-az",
+				labelRegion:           "fd-r",
+				labelAvailabilityZone: "fd-az",
 			},
 		},
 	}, nil

middleware/kubernetes/setup.go

@@ -96,7 +96,7 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 						for _, cidrStr := range args {
 							_, cidr, err := net.ParseCIDR(cidrStr)
 							if err != nil {
-								return nil, errors.New("Invalid cidr: " + cidrStr)
+								return nil, fmt.Errorf("invalid cidr: %s", cidrStr)
 							}
 							k8s.ReverseCidrs = append(k8s.ReverseCidrs, *cidr)
 
@@ -111,7 +111,7 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 						case PodModeDisabled, PodModeInsecure, PodModeVerified:
 							k8s.PodMode = args[0]
 						default:
-							return nil, errors.New("Value for pods must be one of: disabled, verified, insecure")
+							return nil, fmt.Errorf("wrong value for pods: %s,  must be one of: disabled, verified, insecure", args[0])
 						}
 						continue
 					}
@@ -142,7 +142,7 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 					if len(args) > 0 {
 						rp, err := time.ParseDuration(args[0])
 						if err != nil {
-							return nil, 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 nil, fmt.Errorf("unable to parse resync duration value: '%v': %v", args[0], err)
 						}
 						k8s.ResyncPeriod = rp
 						continue
@@ -154,7 +154,7 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 						labelSelectorString := strings.Join(args, " ")
 						ls, err := unversionedapi.ParseToLabelSelector(labelSelectorString)
 						if err != nil {
-							return nil, fmt.Errorf("Unable to parse label selector. Value provided was '%v'. Error was: %v", labelSelectorString, err)
+							return nil, fmt.Errorf("unable to parse label selector value: '%v': %v", labelSelectorString, err)
 						}
 						k8s.LabelSelector = ls
 						continue
@@ -185,17 +185,15 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 							zone: args[1],
 						})
 						continue
-					} else {
-						return nil, fmt.Errorf("Incorrect number of arguments for federation. Got %v, expect 2.", len(args))
 					}
-					return nil, c.ArgErr()
+					return nil, fmt.Errorf("incorrect number of arguments for federation, got %v, expected 2", len(args))
 
 				}
 			}
 			return k8s, nil
 		}
 	}
-	return nil, errors.New("Kubernetes setup called without keyword 'kubernetes' in Corefile")
+	return nil, errors.New("kubernetes setup called without keyword 'kubernetes' in Corefile")
 }
 
 const (

middleware/kubernetes/setup_test.go

@@ -223,7 +223,7 @@ func TestKubernetesParse(t *testing.T) {
 			"no kubernetes keyword",
 			"",
 			true,
-			"Kubernetes setup called without keyword 'kubernetes' in Corefile",
+			"kubernetes setup called without keyword 'kubernetes' in Corefile",
 			-1,
 			-1,
 			defaultResyncPeriod,
@@ -255,7 +255,7 @@ func TestKubernetesParse(t *testing.T) {
     endpoint
 }`,
 			true,
-			"Wrong argument count or unexpected line ending after 'endpoint'",
+			"rong argument count or unexpected line ending",
 			-1,
 			-1,
 			defaultResyncPeriod,
@@ -272,7 +272,7 @@ func TestKubernetesParse(t *testing.T) {
 	namespaces
 }`,
 			true,
-			"Parse error: Wrong argument count or unexpected line ending after 'namespaces'",
+			"rong argument count or unexpected line ending",
 			-1,
 			-1,
 			defaultResyncPeriod,
@@ -289,7 +289,7 @@ func TestKubernetesParse(t *testing.T) {
     resyncperiod
 }`,
 			true,
-			"Wrong argument count or unexpected line ending after 'resyncperiod'",
+			"rong argument count or unexpected line ending",
 			-1,
 			0,
 			0 * time.Minute,
@@ -306,7 +306,7 @@ func TestKubernetesParse(t *testing.T) {
     resyncperiod 15
 }`,
 			true,
-			"Unable to parse resync duration value. Value provided was ",
+			"unable to parse resync duration value",
 			-1,
 			0,
 			0 * time.Second,
@@ -323,7 +323,7 @@ func TestKubernetesParse(t *testing.T) {
     resyncperiod abc
 }`,
 			true,
-			"Unable to parse resync duration value. Value provided was ",
+			"unable to parse resync duration value",
 			-1,
 			0,
 			0 * time.Second,
@@ -340,7 +340,7 @@ func TestKubernetesParse(t *testing.T) {
     labels
 }`,
 			true,
-			"Wrong argument count or unexpected line ending after 'labels'",
+			"rong argument count or unexpected line ending",
 			-1,
 			0,
 			0 * time.Second,
@@ -357,7 +357,7 @@ func TestKubernetesParse(t *testing.T) {
     labels environment in (production, qa
 }`,
 			true,
-			"Unable to parse label selector. Value provided was",
+			"unable to parse label selector",
 			-1,
 			0,
 			0 * time.Second,
@@ -429,7 +429,7 @@ func TestKubernetesParse(t *testing.T) {
 	pods giant_seed
 }`,
 			true,
-			"Value for pods must be one of: disabled, verified, insecure",
+			"rong value for pods",
 			-1,
 			0,
 			defaultResyncPeriod,
@@ -460,12 +460,12 @@ func TestKubernetesParse(t *testing.T) {
 		},
 		// cidrs ok
 		{
-			"Invalid cidr: hard",
+			"invalid cidr: hard",
 			`kubernetes coredns.local {
 	cidrs hard dry
 }`,
 			true,
-			"Invalid cidr: hard",
+			"invalid cidr: hard",
 			-1,
 			0,
 			defaultResyncPeriod,
@@ -483,7 +483,7 @@ func TestKubernetesParse(t *testing.T) {
 	fallthrough junk
 }`,
 			true,
-			"Wrong argument count",
+			"rong argument count",
 			-1,
 			0,
 			defaultResyncPeriod,
@@ -559,7 +559,7 @@ func TestKubernetesParse(t *testing.T) {
 	federation starship
 }`,
 			true,
-			`Incorrect number of arguments for federation. Got 1, expect 2.`,
+			`incorrect number of arguments for federation`,
 			-1,
 			0,
 			defaultResyncPeriod,

middleware/pkg/response/typify.go

@@ -108,7 +108,7 @@ func Typify(m *dns.Msg, t time.Time) (Type, *dns.OPT) {
 		return NameError, opt
 	}
 
-	if ns > 0 && ns > 0 && m.Rcode == dns.RcodeSuccess {
+	if ns > 0 && m.Rcode == dns.RcodeSuccess {
 		return Delegation, opt
 	}
 

middleware/pkg/tls/tls.go

@@ -50,7 +50,7 @@ func NewTLSConfigFromArgs(args ...string) (*tls.Config, error) {
 		// Client cert, use specified CA
 		c, err = NewTLSConfig(args[0], args[1], args[2])
 	default:
-		err = fmt.Errorf("Maximum of three arguments allowed for TLS config, found %d", len(args))
+		err = fmt.Errorf("maximum of three arguments allowed for TLS config, found %d", len(args))
 	}
 	if err != nil {
 		return nil, err
@@ -64,7 +64,7 @@ func NewTLSConfigFromArgs(args ...string) (*tls.Config, error) {
 func NewTLSConfig(certPath, keyPath, caPath string) (*tls.Config, error) {
 	cert, err := tls.LoadX509KeyPair(certPath, keyPath)
 	if err != nil {
-		return nil, fmt.Errorf("Could not load TLS cert: %s", err)
+		return nil, fmt.Errorf("could not load TLS cert: %s", err)
 	}
 
 	roots, err := loadRoots(caPath)
@@ -94,11 +94,11 @@ func loadRoots(caPath string) (*x509.CertPool, error) {
 	roots := x509.NewCertPool()
 	pem, err := ioutil.ReadFile(caPath)
 	if err != nil {
-		return nil, fmt.Errorf("Error reading %s: %s", caPath, err)
+		return nil, fmt.Errorf("error reading %s: %s", caPath, err)
 	}
 	ok := roots.AppendCertsFromPEM(pem)
 	if !ok {
-		return nil, fmt.Errorf("Could not read root certs: %s", err)
+		return nil, fmt.Errorf("could not read root certs: %s", err)
 	}
 	return roots, nil
 }

middleware/proxy/dns.go

@@ -15,6 +15,7 @@ type dnsEx struct {
 	Options
 }
 
+// Options define the options understood by dns.Exchange.
 type Options struct {
 	ForceTCP bool // If true use TCP for upstream no matter what
 }

middleware/proxy/lookup.go

@@ -17,7 +17,7 @@ func NewLookup(hosts []string) Proxy {
 	return NewLookupWithOption(hosts, Options{})
 }
 
-// NewLookupWithForcedProto process creates a simple round robin forward with potentially forced proto for upstream.
+// NewLookupWithOption process creates a simple round robin forward with potentially forced proto for upstream.
 func NewLookupWithOption(hosts []string, opts Options) Proxy {
 	p := Proxy{Next: nil}
 

middleware/rewrite/condition.go

@@ -23,7 +23,7 @@ const (
 )
 
 func operatorError(operator string) error {
-	return fmt.Errorf("Invalid operator %v", operator)
+	return fmt.Errorf("invalid operator %v", operator)
 }
 
 func newReplacer(r *dns.Msg) replacer.Replacer {

middleware/rewrite/edns0.go

@@ -94,7 +94,7 @@ func (rule *edns0LocalRule) Rewrite(r *dns.Msg) Result {
 // newEdns0Rule creates an EDNS0 rule of the appropriate type based on the args
 func newEdns0Rule(args ...string) (Rule, error) {
 	if len(args) < 2 {
-		return nil, fmt.Errorf("Too few arguments for an EDNS0 rule")
+		return nil, fmt.Errorf("too few arguments for an EDNS0 rule")
 	}
 
 	ruleType := strings.ToLower(args[0])

middleware/rewrite/rewrite.go

@@ -64,7 +64,7 @@ type Rule interface {
 
 func newRule(args ...string) (Rule, error) {
 	if len(args) == 0 {
-		return nil, fmt.Errorf("No rule type specified for rewrite")
+		return nil, fmt.Errorf("no rule type specified for rewrite")
 	}
 
 	ruleType := strings.ToLower(args[0])

middleware/trace/trace.go

@@ -7,11 +7,12 @@ import (
 	"sync/atomic"
 
 	"github.com/coredns/coredns/middleware"
+	// Plugin the trace package.
 	_ "github.com/coredns/coredns/middleware/pkg/trace"
+
 	"github.com/miekg/dns"
 	ot "github.com/opentracing/opentracing-go"
 	zipkin "github.com/openzipkin/zipkin-go-opentracing"
-
 	"golang.org/x/net/context"
 )
 
@@ -40,7 +41,7 @@ func (t *trace) OnStartup() error {
 		case "zipkin":
 			err = t.setupZipkin()
 		default:
-			err = fmt.Errorf("Unknown endpoint type: %s", t.EndpointType)
+			err = fmt.Errorf("unknown endpoint type: %s", t.EndpointType)
 		}
 	})
 	return err

test/grpc_test.go

@@ -52,10 +52,10 @@ func TestGrpc(t *testing.T) {
 	}
 
 	if d.Rcode != dns.RcodeSuccess {
-		t.Errorf("Expected success but got %s", d.Rcode)
+		t.Errorf("Expected success but got %d", d.Rcode)
 	}
 
 	if len(d.Extra) != 2 {
-		t.Errorf("Expected 2 RRs in additional section, but got %s", len(d.Extra))
+		t.Errorf("Expected 2 RRs in additional section, but got %d", len(d.Extra))
 	}
 }

test/reload_test.go

@@ -45,6 +45,6 @@ func send(t *testing.T, server string) {
 		t.Fatalf("Expected successful reply, got %s", dns.RcodeToString[r.Rcode])
 	}
 	if len(r.Extra) != 2 {
-		t.Fatalf("Expected 2 RRs in additional, got %s", len(r.Extra))
+		t.Fatalf("Expected 2 RRs in additional, got %d", len(r.Extra))
 	}
 }