Golint2 (#280)

* Fix linter errors

* More linting fixes

* More docs and making members private that dont need to be public

* Fix linter errors

* More linting fixes

* More docs and making members private that dont need to be public

* More lint fixes

This leaves:

~~~
middleware/kubernetes/nametemplate/nametemplate.go:64:6: exported type NameTemplate should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:71:1: exported method NameTemplate.SetTemplate should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:108:1: exported method NameTemplate.GetZoneFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:116:1: exported method NameTemplate.GetNamespaceFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:120:1: exported method NameTemplate.GetServiceFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:124:1: exported method NameTemplate.GetTypeFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:135:1: exported method NameTemplate.GetSymbolFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:167:1: exported method NameTemplate.IsValid should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:182:6: exported type NameValues should have comment or be unexported
middleware/kubernetes/util/util.go:1:1: package comment should be of the form "Package util ..."
middleware/kubernetes/util/util.go:27:2: exported const WildcardStar should have comment (or a comment on this block) or be unexported
middleware/proxy/lookup.go:66:1: exported method Proxy.Forward should have comment or be unexported
middleware/proxy/proxy.go:24:6: exported type Client should have comment or be unexported
middleware/proxy/proxy.go:107:1: exported function Clients should have comment or be unexported
middleware/proxy/reverseproxy.go:10:6: exported type ReverseProxy should have comment or be unexported
middleware/proxy/reverseproxy.go:16:1: exported method ReverseProxy.ServeDNS should have comment or be unexported
middleware/proxy/upstream.go:42:6: exported type Options should have comment or be unexported
~~~

I plan on reworking the proxy anyway, so I'll leave that be.

middleware/cache/cache.go

@@ -20,6 +20,7 @@ type Cache struct {
 	cap   time.Duration
 }
 
+// NewCache returns a new cache.
 func NewCache(ttl int, zones []string, next middleware.Handler) Cache {
 	return Cache{Next: next, Zones: zones, cache: gcache.New(defaultDuration, purgeDuration), cap: time.Duration(ttl) * time.Second}
 }
@@ -46,17 +47,20 @@ func cacheKey(m *dns.Msg, t response.Type, do bool) string {
 	return ""
 }
 
-type CachingResponseWriter struct {
+// ResponseWriter is a response writer that caches the reply message.
+type ResponseWriter struct {
 	dns.ResponseWriter
 	cache *gcache.Cache
 	cap   time.Duration
 }
 
-func NewCachingResponseWriter(w dns.ResponseWriter, cache *gcache.Cache, cap time.Duration) *CachingResponseWriter {
+// NewCachingResponseWriter returns a new ResponseWriter.
-	return &CachingResponseWriter{w, cache, cap}
+func NewCachingResponseWriter(w dns.ResponseWriter, cache *gcache.Cache, cap time.Duration) *ResponseWriter {
+	return &ResponseWriter{w, cache, cap}
 }
 
-func (c *CachingResponseWriter) WriteMsg(res *dns.Msg) error {
+// WriteMsg implements the dns.ResponseWriter interface.
+func (c *ResponseWriter) WriteMsg(res *dns.Msg) error {
 	do := false
 	mt, opt := response.Classify(res)
 	if opt != nil {
@@ -73,7 +77,7 @@ func (c *CachingResponseWriter) WriteMsg(res *dns.Msg) error {
 	return c.ResponseWriter.WriteMsg(res)
 }
 
-func (c *CachingResponseWriter) set(m *dns.Msg, key string, mt response.Type) {
+func (c *ResponseWriter) set(m *dns.Msg, key string, mt response.Type) {
 	if key == "" {
 		log.Printf("[ERROR] Caching called with empty cache key")
 		return
@@ -83,14 +87,14 @@ func (c *CachingResponseWriter) set(m *dns.Msg, key string, mt response.Type) {
 	switch mt {
 	case response.Success, response.Delegation:
 		if c.cap == 0 {
-			duration = minTtl(m.Answer, mt)
+			duration = minTTL(m.Answer, mt)
 		}
 		i := newItem(m, duration)
 
 		c.cache.Set(key, i, duration)
 	case response.NameError, response.NoData:
 		if c.cap == 0 {
-			duration = minTtl(m.Ns, mt)
+			duration = minTTL(m.Ns, mt)
 		}
 		i := newItem(m, duration)
 
@@ -102,23 +106,25 @@ func (c *CachingResponseWriter) set(m *dns.Msg, key string, mt response.Type) {
 	}
 }
 
-func (c *CachingResponseWriter) Write(buf []byte) (int, error) {
+// Write implements the dns.ResponseWriter interface.
+func (c *ResponseWriter) Write(buf []byte) (int, error) {
 	log.Printf("[WARNING] Caching called with Write: not caching reply")
 	n, err := c.ResponseWriter.Write(buf)
 	return n, err
 }
 
-func (c *CachingResponseWriter) Hijack() {
+// Hijack implements the dns.ResponseWriter interface.
+func (c *ResponseWriter) Hijack() {
 	c.ResponseWriter.Hijack()
 	return
 }
 
-func minTtl(rrs []dns.RR, mt response.Type) time.Duration {
+func minTTL(rrs []dns.RR, mt response.Type) time.Duration {
 	if mt != response.Success && mt != response.NameError && mt != response.NoData {
 		return 0
 	}
 
-	minTtl := maxTtl
+	minTTL := maxTTL
 	for _, r := range rrs {
 		switch mt {
 		case response.NameError, response.NoData:
@@ -126,17 +132,17 @@ func minTtl(rrs []dns.RR, mt response.Type) time.Duration {
 				return time.Duration(r.(*dns.SOA).Minttl) * time.Second
 			}
 		case response.Success, response.Delegation:
-			if r.Header().Ttl < minTtl {
+			if r.Header().Ttl < minTTL {
-				minTtl = r.Header().Ttl
+				minTTL = r.Header().Ttl
 			}
 		}
 	}
-	return time.Duration(minTtl) * time.Second
+	return time.Duration(minTTL) * time.Second
 }
 
 const (
 	purgeDuration          = 1 * time.Minute
 	defaultDuration        = 20 * time.Minute
-	baseTtl                = 5 // minimum ttl that we will allow
+	baseTTL                = 5 // minimum TTL that we will allow
-	maxTtl          uint32 = 2 * 3600
+	maxTTL          uint32 = 2 * 3600
 )

middleware/cache/cache_test.go

@@ -65,7 +65,7 @@ func cacheMsg(m *dns.Msg, tc cacheTestCase) *dns.Msg {
 	return m
 }
 
-func newTestCache() (Cache, *CachingResponseWriter) {
+func newTestCache() (Cache, *ResponseWriter) {
 	c := NewCache(0, []string{"."}, nil)
 	crr := NewCachingResponseWriter(nil, c.cache, time.Duration(0))
 	return c, crr

middleware/cache/item.go

@@ -15,7 +15,7 @@ type item struct {
 	Ns                 []dns.RR
 	Extra              []dns.RR
 
-	origTtl uint32
+	origTTL uint32
 	stored  time.Time
 }
 
@@ -38,7 +38,7 @@ func newItem(m *dns.Msg, d time.Duration) *item {
 	}
 	i.Extra = i.Extra[:j]
 
-	i.origTtl = uint32(d.Seconds())
+	i.origTTL = uint32(d.Seconds())
 	i.stored = time.Now().UTC()
 
 	return i
@@ -57,9 +57,9 @@ func (i *item) toMsg(m *dns.Msg) *dns.Msg {
 	m1.Ns = i.Ns
 	m1.Extra = i.Extra
 
-	ttl := int(i.origTtl) - int(time.Now().UTC().Sub(i.stored).Seconds())
+	ttl := int(i.origTTL) - int(time.Now().UTC().Sub(i.stored).Seconds())
-	if ttl < baseTtl {
+	if ttl < baseTTL {
-		ttl = baseTtl
+		ttl = baseTTL
 	}
 	setCap(m1, uint32(ttl))
 	return m1

middleware/chaos/chaos.go

@@ -18,6 +18,7 @@ type Chaos struct {
 	Authors map[string]bool
 }
 
+// ServeDNS implements the middleware.Handler interface.
 func (c Chaos) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 	if state.QClass() != dns.ClassCHAOS || state.QType() != dns.TypeTXT {
@@ -32,7 +33,7 @@ func (c Chaos) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (
 	default:
 		return c.Next.ServeDNS(ctx, w, r)
 	case "authors.bind.":
-		for a, _ := range c.Authors {
+		for a := range c.Authors {
 			m.Answer = append(m.Answer, &dns.TXT{Hdr: hdr, Txt: []string{trim(a)}})
 		}
 	case "version.bind.", "version.server.":

middleware/dnssec/dnskey.go

@@ -13,6 +13,7 @@ import (
 	"github.com/miekg/dns"
 )
 
+// DNSKEY holds a DNSSEC public and private key used for on-the-fly signing.
 type DNSKEY struct {
 	K      *dns.DNSKEY
 	s      crypto.Signer

middleware/dnssec/dnssec.go

@@ -12,6 +12,7 @@ import (
 	gcache "github.com/patrickmn/go-cache"
 )
 
+// Dnssec signs the reply on-the-fly.
 type Dnssec struct {
 	Next middleware.Handler
 
@@ -21,6 +22,7 @@ type Dnssec struct {
 	cache    *gcache.Cache
 }
 
+// New returns a new Dnssec.
 func New(zones []string, keys []*DNSKEY, next middleware.Handler) Dnssec {
 	return Dnssec{Next: next,
 		zones:    zones,
@@ -95,7 +97,7 @@ func (d Dnssec) sign(rrs []dns.RR, signerName string, ttl, incep, expir uint32)
 		sigs := make([]dns.RR, len(d.keys))
 		var e error
 		for i, k := range d.keys {
-			sig := k.NewRRSIG(signerName, ttl, incep, expir)
+			sig := k.newRRSIG(signerName, ttl, incep, expir)
 			e = sig.Sign(k.s, rrs)
 			sigs[i] = sig
 		}

middleware/dnssec/handler.go

@@ -35,7 +35,7 @@ func (d Dnssec) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
 		}
 	}
 
-	drr := NewDnssecResponseWriter(w, d)
+	drr := &ResponseWriter{w, d}
 	return d.Next.ServeDNS(ctx, drr, r)
 }
 

middleware/dnssec/responsewriter.go

@@ -10,15 +10,13 @@ import (
 	"github.com/miekg/dns"
 )
 
+// ResponseWriter sign the response on the fly.
 type ResponseWriter struct {
 	dns.ResponseWriter
 	d Dnssec
 }
 
-func NewDnssecResponseWriter(w dns.ResponseWriter, d Dnssec) *ResponseWriter {
+// WriteMsg implements the dns.ResponseWriter interface.
-	return &ResponseWriter{w, d}
-}
-
 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.
@@ -38,13 +36,12 @@ func (d *ResponseWriter) WriteMsg(res *dns.Msg) error {
 	return d.ResponseWriter.WriteMsg(res)
 }
 
+// Write implements the dns.ResponseWriter interface.
 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 *ResponseWriter) Hijack() {
+// Hijack implements the dns.ResponseWriter interface.
-	d.ResponseWriter.Hijack()
+func (d *ResponseWriter) Hijack() { d.ResponseWriter.Hijack() }
-	return
-}

middleware/dnssec/rrsig.go

@@ -3,7 +3,7 @@ package dnssec
 import "github.com/miekg/dns"
 
 // newRRSIG return a new RRSIG, with all fields filled out, except the signed data.
-func (k *DNSKEY) NewRRSIG(signerName string, ttl, incep, expir uint32) *dns.RRSIG {
+func (k *DNSKEY) newRRSIG(signerName string, ttl, incep, expir uint32) *dns.RRSIG {
 	sig := new(dns.RRSIG)
 
 	sig.Hdr.Rrtype = dns.TypeRRSIG
@@ -11,7 +11,7 @@ func (k *DNSKEY) NewRRSIG(signerName string, ttl, incep, expir uint32) *dns.RRSI
 	sig.KeyTag = k.keytag
 	sig.SignerName = signerName
 	sig.Hdr.Ttl = ttl
-	sig.OrigTtl = origTtl
+	sig.OrigTtl = origTTL
 
 	sig.Inception = incep
 	sig.Expiration = expir
@@ -50,4 +50,4 @@ func rrSets(rrs []dns.RR) map[rrset][]dns.RR {
 	return nil
 }
 
-const origTtl = 3600
+const origTTL = 3600

middleware/dnssec/setup.go

@@ -52,7 +52,7 @@ func dnssecParse(c *caddy.Controller) ([]string, []*DNSKEY, error) {
 			}
 		}
 	}
-	for i, _ := range zones {
+	for i := range zones {
 		zones[i] = middleware.Host(zones[i]).Normalize()
 	}
 	return zones, keys, nil

middleware/errors/errors.go

@@ -15,15 +15,16 @@ import (
 	"golang.org/x/net/context"
 )
 
-// ErrorHandler handles DNS errors (and errors from other middleware).
+// errorHandler handles DNS errors (and errors from other middleware).
-type ErrorHandler struct {
+type errorHandler struct {
 	Next    middleware.Handler
 	LogFile string
 	Log     *log.Logger
 	Debug   bool // if true, errors are written out to client rather than to a log
 }
 
-func (h ErrorHandler) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+// ServeDNS implements the middleware.Handler interface.
+func (h errorHandler) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	defer h.recovery(ctx, w, r)
 
 	rcode, err := h.Next.ServeDNS(ctx, w, r)
@@ -47,7 +48,7 @@ func (h ErrorHandler) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns
 	return rcode, err
 }
 
-func (h ErrorHandler) recovery(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) {
+func (h errorHandler) recovery(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) {
 	rec := recover()
 	if rec == nil {
 		return

middleware/errors/errors_test.go

@@ -18,7 +18,7 @@ import (
 
 func TestErrors(t *testing.T) {
 	buf := bytes.Buffer{}
-	em := ErrorHandler{Log: log.New(&buf, "", 0)}
+	em := errorHandler{Log: log.New(&buf, "", 0)}
 
 	testErr := errors.New("test error")
 	tests := []struct {
@@ -68,7 +68,7 @@ func TestErrors(t *testing.T) {
 
 func TestVisibleErrorWithPanic(t *testing.T) {
 	const panicMsg = "I'm a panic"
-	eh := ErrorHandler{
+	eh := errorHandler{
 		Debug: true,
 		Next: middleware.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 			panic(panicMsg)

middleware/errors/setup.go

@@ -62,8 +62,8 @@ func setup(c *caddy.Controller) error {
 	return nil
 }
 
-func errorsParse(c *caddy.Controller) (ErrorHandler, error) {
+func errorsParse(c *caddy.Controller) (errorHandler, error) {
-	handler := ErrorHandler{}
+	handler := errorHandler{}
 
 	optionalBlock := func() (bool, error) {
 		var hadBlock bool

middleware/errors/setup_test.go

@@ -10,19 +10,19 @@ func TestErrorsParse(t *testing.T) {
 	tests := []struct {
 		inputErrorsRules     string
 		shouldErr            bool
-		expectedErrorHandler ErrorHandler
+		expectedErrorHandler errorHandler
 	}{
-		{`errors`, false, ErrorHandler{
+		{`errors`, false, errorHandler{
 			LogFile: "",
 		}},
-		{`errors errors.txt`, false, ErrorHandler{
+		{`errors errors.txt`, false, errorHandler{
 			LogFile: "errors.txt",
 		}},
-		{`errors visible`, false, ErrorHandler{
+		{`errors visible`, false, errorHandler{
 			LogFile: "",
 			Debug:   true,
 		}},
-		{`errors { log visible }`, false, ErrorHandler{
+		{`errors { log visible }`, false, errorHandler{
 			LogFile: "",
 			Debug:   true,
 		}},

middleware/etcd/etcd.go

@@ -16,6 +16,7 @@ import (
 	"golang.org/x/net/context"
 )
 
+// Etcd is a middleware talks to an etcd cluster.
 type Etcd struct {
 	Next       middleware.Handler
 	Zones      []string
@@ -113,7 +114,7 @@ Nodes:
 		bx[b] = true
 
 		serv.Key = n.Key
-		serv.Ttl = e.TTL(n, serv)
+		serv.TTL = e.TTL(n, serv)
 		if serv.Priority == 0 {
 			serv.Priority = priority
 		}
@@ -127,19 +128,19 @@ Nodes:
 func (e *Etcd) TTL(node *etcdc.Node, serv *msg.Service) uint32 {
 	etcdTTL := uint32(node.TTL)
 
-	if etcdTTL == 0 && serv.Ttl == 0 {
+	if etcdTTL == 0 && serv.TTL == 0 {
 		return ttl
 	}
 	if etcdTTL == 0 {
-		return serv.Ttl
+		return serv.TTL
 	}
-	if serv.Ttl == 0 {
+	if serv.TTL == 0 {
 		return etcdTTL
 	}
-	if etcdTTL < serv.Ttl {
+	if etcdTTL < serv.TTL {
 		return etcdTTL
 	}
-	return serv.Ttl
+	return serv.TTL
 }
 
 // etcNameError checks if the error is ErrorCodeKeyNotFound from etcd.

middleware/etcd/handler.go

@@ -5,12 +5,14 @@ import (
 
 	"github.com/miekg/coredns/middleware"
 	"github.com/miekg/coredns/middleware/etcd/msg"
+	"github.com/miekg/coredns/middleware/pkg/dnsutil"
 	"github.com/miekg/coredns/request"
 
 	"github.com/miekg/dns"
 	"golang.org/x/net/context"
 )
 
+// ServeDNS implements the middleware.Handler interface.
 func (e *Etcd) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	opt := Options{}
 	state := request.Request{W: w, Req: r}
@@ -108,7 +110,7 @@ func (e *Etcd) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (
 		m.Extra = append(m.Extra, servicesToTxt(debug)...)
 	}
 
-	m = dedup(m)
+	m = dnsutil.Dedup(m)
 	state.SizeAndDo(m)
 	m, _ = state.Scrub(m)
 	w.WriteMsg(m)
@@ -133,11 +135,3 @@ func (e *Etcd) Err(zone string, rcode int, state request.Request, debug []msg.Se
 	// Return success as the rcode to signal we have written to the client.
 	return dns.RcodeSuccess, nil
 }
-
-func dedup(m *dns.Msg) *dns.Msg {
-	// TODO(miek): expensive!
-	m.Answer = dns.Dedup(m.Answer, nil)
-	m.Ns = dns.Dedup(m.Ns, nil)
-	m.Extra = dns.Dedup(m.Extra, nil)
-	return m
-}

middleware/etcd/lookup.go

@@ -14,8 +14,9 @@ import (
 	"github.com/miekg/dns"
 )
 
+// Options are extra options that can be specified for a lookup.
 type Options struct {
-	Debug string
+	Debug string // This is a debug query. A query prefixed with debug.o-o
 }
 
 func (e Etcd) records(state request.Request, exact bool, opt Options) (services, debug []msg.Service, err error) {
@@ -30,6 +31,7 @@ func (e Etcd) records(state request.Request, exact bool, opt Options) (services,
 	return
 }
 
+// A returns A records from etcd or an error.
 func (e Etcd) A(zone string, state request.Request, previousRecords []dns.RR, opt Options) (records []dns.RR, debug []msg.Service, err error) {
 	services, debug, err := e.records(state, false, opt)
 	if err != nil {
@@ -92,6 +94,7 @@ func (e Etcd) A(zone string, state request.Request, previousRecords []dns.RR, op
 	return records, debug, nil
 }
 
+// AAAA returns AAAA records from etcd or an error.
 func (e Etcd) AAAA(zone string, state request.Request, previousRecords []dns.RR, opt Options) (records []dns.RR, debug []msg.Service, err error) {
 	services, debug, err := e.records(state, false, opt)
 	if err != nil {
@@ -313,6 +316,7 @@ func (e Etcd) MX(zone string, state request.Request, opt Options) (records, extr
 	return records, extra, debug, nil
 }
 
+// CNAME returns CNAME records from etcd or an error.
 func (e Etcd) CNAME(zone string, state request.Request, opt Options) (records []dns.RR, debug []msg.Service, err error) {
 	services, debug, err := e.records(state, true, opt)
 	if err != nil {
@@ -343,6 +347,7 @@ func (e Etcd) PTR(zone string, state request.Request, opt Options) (records []dn
 	return records, debug, nil
 }
 
+// TXT returns TXT records from etcd or an error.
 func (e Etcd) TXT(zone string, state request.Request, opt Options) (records []dns.RR, debug []msg.Service, err error) {
 	services, debug, err := e.records(state, false, opt)
 	if err != nil {
@@ -358,6 +363,7 @@ func (e Etcd) TXT(zone string, state request.Request, opt Options) (records []dn
 	return records, debug, nil
 }
 
+// NS returns NS records from etcd or an error.
 func (e Etcd) NS(zone string, state request.Request, opt Options) (records, extra []dns.RR, debug []msg.Service, err error) {
 	// NS record for this zone live in a special place, ns.dns.<zone>. Fake our lookup.
 	// only a tad bit fishy...
@@ -390,7 +396,7 @@ func (e Etcd) NS(zone string, state request.Request, opt Options) (records, extr
 	return records, extra, debug, nil
 }
 
-// SOA Record returns a SOA record.
+// SOA returns a SOA record from etcd.
 func (e Etcd) SOA(zone string, state request.Request, opt Options) ([]dns.RR, []msg.Service, error) {
 	header := dns.RR_Header{Name: zone, Rrtype: dns.TypeSOA, Ttl: 300, Class: dns.ClassINET}
 

middleware/etcd/msg/path.go

@@ -27,7 +27,7 @@ func Domain(s string) string {
 	return dns.Fqdn(strings.Join(l[1:len(l)-1], "."))
 }
 
-// As Path, but if a name contains wildcards (* or any), the name will be
+// PathWithWildcard ascts as Path, but if a name contains wildcards (* or any), the name will be
 // chopped of before the (first) wildcard, and we do a highler evel search and
 // later find the matching names.  So service.*.skydns.local, will look for all
 // services under skydns.local and will later check for names that match

middleware/etcd/msg/service.go

@@ -8,9 +8,9 @@ import (
 	"github.com/miekg/dns"
 )
 
-// This *is* the rdata from a SRV record, but with a twist.
+// Service defines a discoverable service in etcd. It is the rdata from a SRV
-// Host (Target in SRV) must be a domain name, but if it looks like an IP
+// record, but with a twist.  Host (Target in SRV) must be a domain name, but
-// address (4/6), we will treat it like an IP address.
+// if it looks like an IP address (4/6), we will treat it like an IP address.
 type Service struct {
 	Host     string `json:"host,omitempty"`
 	Port     int    `json:"port,omitempty"`
@@ -18,7 +18,7 @@ type Service struct {
 	Weight   int    `json:"weight,omitempty"`
 	Text     string `json:"text,omitempty"`
 	Mail     bool   `json:"mail,omitempty"` // Be an MX record. Priority becomes Preference.
-	Ttl      uint32 `json:"ttl,omitempty"`
+	TTL      uint32 `json:"ttl,omitempty"`
 
 	// When a SRV record with a "Host: IP-address" is added, we synthesize
 	// a srv.Target domain name.  Normally we convert the full Key where
@@ -54,7 +54,7 @@ func (s *Service) RR() *dns.TXT {
 	}
 	t := new(dns.TXT)
 	t.Hdr.Class = dns.ClassCHAOS
-	t.Hdr.Ttl = s.Ttl
+	t.Hdr.Ttl = s.TTL
 	t.Hdr.Rrtype = dns.TypeTXT
 	t.Hdr.Name = Domain(s.Key)
 
@@ -70,7 +70,7 @@ func (s *Service) RR() *dns.TXT {
 func (s *Service) NewSRV(name string, weight uint16) *dns.SRV {
 	host := targetStrip(dns.Fqdn(s.Host), s.TargetStrip)
 
-	return &dns.SRV{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeSRV, Class: dns.ClassINET, Ttl: s.Ttl},
+	return &dns.SRV{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeSRV, Class: dns.ClassINET, Ttl: s.TTL},
 		Priority: uint16(s.Priority), Weight: weight, Port: uint16(s.Port), Target: dns.Fqdn(host)}
 }
 
@@ -78,39 +78,39 @@ func (s *Service) NewSRV(name string, weight uint16) *dns.SRV {
 func (s *Service) NewMX(name string) *dns.MX {
 	host := targetStrip(dns.Fqdn(s.Host), s.TargetStrip)
 
-	return &dns.MX{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeMX, Class: dns.ClassINET, Ttl: s.Ttl},
+	return &dns.MX{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeMX, Class: dns.ClassINET, Ttl: s.TTL},
 		Preference: uint16(s.Priority), Mx: host}
 }
 
 // NewA returns a new A record based on the Service.
 func (s *Service) NewA(name string, ip net.IP) *dns.A {
-	return &dns.A{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.Ttl}, A: ip}
+	return &dns.A{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.TTL}, A: ip}
 }
 
 // NewAAAA returns a new AAAA record based on the Service.
 func (s *Service) NewAAAA(name string, ip net.IP) *dns.AAAA {
-	return &dns.AAAA{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.Ttl}, AAAA: ip}
+	return &dns.AAAA{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.TTL}, AAAA: ip}
 }
 
 // NewCNAME returns a new CNAME record based on the Service.
 func (s *Service) NewCNAME(name string, target string) *dns.CNAME {
-	return &dns.CNAME{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeCNAME, Class: dns.ClassINET, Ttl: s.Ttl}, Target: dns.Fqdn(target)}
+	return &dns.CNAME{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeCNAME, Class: dns.ClassINET, Ttl: s.TTL}, Target: dns.Fqdn(target)}
 }
 
 // NewTXT returns a new TXT record based on the Service.
 func (s *Service) NewTXT(name string) *dns.TXT {
-	return &dns.TXT{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: s.Ttl}, Txt: split255(s.Text)}
+	return &dns.TXT{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: s.TTL}, Txt: split255(s.Text)}
 }
 
 // NewPTR returns a new PTR record based on the Service.
 func (s *Service) NewPTR(name string, target string) *dns.PTR {
-	return &dns.PTR{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypePTR, Class: dns.ClassINET, Ttl: s.Ttl}, Ptr: dns.Fqdn(target)}
+	return &dns.PTR{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypePTR, Class: dns.ClassINET, Ttl: s.TTL}, Ptr: dns.Fqdn(target)}
 }
 
 // NewNS returns a new NS record based on the Service.
 func (s *Service) NewNS(name string) *dns.NS {
 	host := targetStrip(dns.Fqdn(s.Host), s.TargetStrip)
-	return &dns.NS{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeNS, Class: dns.ClassINET, Ttl: s.Ttl}, Ns: host}
+	return &dns.NS{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeNS, Class: dns.ClassINET, Ttl: s.TTL}, Ns: host}
 }
 
 // Group checks the services in sx, it looks for a Group attribute on the shortest

middleware/etcd/setup.go

@@ -171,7 +171,7 @@ func newEtcdClient(endpoints []string, tlsCert, tlsKey, tlsCACert string) (etcdc
 }
 
 func newHTTPSTransport(tlsCertFile, tlsKeyFile, tlsCACertFile string) etcdc.CancelableTransport {
-	var cc *tls.Config = nil
+	var cc *tls.Config
 
 	if tlsCertFile != "" && tlsKeyFile != "" {
 		var rpool *x509.CertPool

middleware/etcd/stub.go

@@ -13,6 +13,7 @@ import (
 	"github.com/miekg/dns"
 )
 
+// UpdateStubZones checks etcd for an update on the stubzones.
 func (e *Etcd) UpdateStubZones() {
 	go func() {
 		for {

middleware/etcd/stub_handler.go

@@ -16,6 +16,7 @@ type Stub struct {
 	Zone string // for what zone (and thus what nameservers are we called)
 }
 
+// ServeDNS implements the middleware.Handler interface.
 func (s Stub) ServeDNS(ctx context.Context, w dns.ResponseWriter, req *dns.Msg) (int, error) {
 	if hasStubEdns0(req) {
 		log.Printf("[WARNING] Forwarding cycle detected, refusing msg: %s", req.Question[0].Name)

middleware/file/delegation_test.go

@@ -46,7 +46,7 @@ var delegationTestCases = []test.Case{
 }
 
 func TestLookupDelegation(t *testing.T) {
-	zone, err := Parse(strings.NewReader(dbMiekNL_delegation), testzone, "stdin")
+	zone, err := Parse(strings.NewReader(dbMiekNLDelegation), testzone, "stdin")
 	if err != nil {
 		t.Fatalf("expect no error when reading zone, got %q", err)
 	}
@@ -85,7 +85,7 @@ func TestLookupDelegation(t *testing.T) {
 	}
 }
 
-const dbMiekNL_delegation = `
+const dbMiekNLDelegation = `
 $TTL    30M
 $ORIGIN miek.nl.
 @       IN      SOA     linode.atoom.net. miek.miek.nl. (

middleware/file/dnssec_test.go

@@ -105,7 +105,7 @@ var dnssecTestCases = []test.Case{
 }
 
 func TestLookupDNSSEC(t *testing.T) {
-	zone, err := Parse(strings.NewReader(dbMiekNL_signed), testzone, "stdin")
+	zone, err := Parse(strings.NewReader(dbMiekNLSigned), testzone, "stdin")
 	if err != nil {
 		t.Fatalf("expect no error when reading zone, got %q", err)
 	}
@@ -147,7 +147,7 @@ func TestLookupDNSSEC(t *testing.T) {
 }
 
 func BenchmarkLookupDNSSEC(b *testing.B) {
-	zone, err := Parse(strings.NewReader(dbMiekNL_signed), testzone, "stdin")
+	zone, err := Parse(strings.NewReader(dbMiekNLSigned), testzone, "stdin")
 	if err != nil {
 		return
 	}
@@ -178,7 +178,7 @@ func BenchmarkLookupDNSSEC(b *testing.B) {
 	}
 }
 
-const dbMiekNL_signed = `
+const dbMiekNLSigned = `
 ; File written on Sun Mar 27 04:13:01 2016
 ; dnssec_signzone version 9.10.3-P4-Ubuntu
 miek.nl.		1800	IN SOA	linode.atoom.net. miek.miek.nl. (

middleware/file/file.go

@@ -13,17 +13,20 @@ import (
 )
 
 type (
+	// File is the middleware that reads zone data from disk.
 	File struct {
 		Next  middleware.Handler
 		Zones Zones
 	}
 
+	// Zones maps zone names to a *Zone.
 	Zones struct {
 		Z     map[string]*Zone
 		Names []string
 	}
 )
 
+// ServeDNS implements the middleware.Handle interface.
 func (f File) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 

middleware/file/lookup.go

@@ -10,10 +10,15 @@ import (
 type Result int
 
 const (
+	// Success is a successful lookup.
 	Success Result = iota
+	// NameError indicates a nameerror
 	NameError
+	// Delegation indicates the lookup resulted in a delegation.
 	Delegation
+	// NoData indicates the lookup resulted in a NODATA.
 	NoData
+	// ServerFailure indicates a server failure during the lookup.
 	ServerFailure
 )
 

middleware/file/nsec3_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestParseNSEC3PARAM(t *testing.T) {
-	_, err := Parse(strings.NewReader(nsec3param_test), "miek.nl", "stdin")
+	_, err := Parse(strings.NewReader(nsec3paramTest), "miek.nl", "stdin")
 	if err == nil {
 		t.Fatalf("expected error when reading zone, got nothing")
 	}
@@ -14,17 +14,17 @@ func TestParseNSEC3PARAM(t *testing.T) {
 }
 
 func TestParseNSEC3(t *testing.T) {
-	_, err := Parse(strings.NewReader(nsec3_test), "miek.nl", "stdin")
+	_, err := Parse(strings.NewReader(nsec3Test), "miek.nl", "stdin")
 	if err == nil {
 		t.Fatalf("expected error when reading zone, got nothing")
 	}
 	t.Logf("%v\n", err)
 }
 
-const nsec3param_test = `miek.nl.	1800	IN	SOA	linode.atoom.net. miek.miek.nl. 1460175181 14400 3600 604800 14400
+const nsec3paramTest = `miek.nl.	1800	IN	SOA	linode.atoom.net. miek.miek.nl. 1460175181 14400 3600 604800 14400
 miek.nl.		1800	IN	NS	omval.tednet.nl.
 miek.nl.		0	IN	NSEC3PARAM 1 0 5 A3DEBC9CC4F695C7`
 
-const nsec3_test = `example.org.		1800	IN	SOA	sns.dns.icann.org. noc.dns.icann.org. 2016082508 7200 3600 1209600 3600
+const nsec3Test = `example.org.		1800	IN	SOA	sns.dns.icann.org. noc.dns.icann.org. 2016082508 7200 3600 1209600 3600
 aub8v9ce95ie18spjubsr058h41n7pa5.example.org. 284 IN NSEC3 1 1 5 D0CBEAAF0AC77314 AUB95P93VPKP55G6U5S4SGS7LS61ND85 NS SOA TXT RRSIG DNSKEY NSEC3PARAM
 aub8v9ce95ie18spjubsr058h41n7pa5.example.org. 284 IN RRSIG NSEC3 8 2 600 20160910232502 20160827231002 14028 example.org. XBNpA7KAIjorPbXvTinOHrc1f630aHic2U716GHLHA4QMx9cl9ss4QjR Wj2UpDM9zBW/jNYb1xb0yjQoez/Jv200w0taSWjRci5aUnRpOi9bmcrz STHb6wIUjUsbJ+NstQsUwVkj6679UviF1FqNwr4GlJnWG3ZrhYhE+NI6 s0k=`

middleware/file/secondary.go

@@ -178,7 +178,6 @@ Restart:
 	}
 }
 
-// The maximum difference between two serial numbers. If the difference between
+// MaxSerialIncrement is the maximum difference between two serial numbers. If the difference between
-// two serials is greater than this number, the smaller one is considered
+// two serials is greater than this number, the smaller one is considered greater.
-// greater.
 const MaxSerialIncrement uint32 = 2147483647

middleware/file/setup.go

@@ -70,7 +70,7 @@ func fileParse(c *caddy.Controller) (Zones, error) {
 				return Zones{}, err
 			}
 
-			for i, _ := range origins {
+			for i := range origins {
 				origins[i] = middleware.Host(origins[i]).Normalize()
 				zone, err := Parse(reader, origins[i], fileName)
 				if err == nil {
@@ -116,7 +116,7 @@ func TransferParse(c *caddy.Controller) (tos, froms []string, err error) {
 	case "transfer":
 		if value == "to" {
 			tos = c.RemainingArgs()
-			for i, _ := range tos {
+			for i := range tos {
 				if tos[i] != "*" {
 					if x := net.ParseIP(tos[i]); x == nil {
 						return nil, nil, fmt.Errorf("must specify an IP addres: `%s'", tos[i])
@@ -127,7 +127,7 @@ func TransferParse(c *caddy.Controller) (tos, froms []string, err error) {
 		}
 		if value == "from" {
 			froms = c.RemainingArgs()
-			for i, _ := range froms {
+			for i := range froms {
 				if froms[i] != "*" {
 					if x := net.ParseIP(froms[i]); x == nil {
 						return nil, nil, fmt.Errorf("must specify an IP addres: `%s'", froms[i])

middleware/file/tree/elem.go

@@ -2,6 +2,7 @@ package tree
 
 import "github.com/miekg/dns"
 
+// Elem is an element in the tree.
 type Elem struct {
 	m map[uint16][]dns.RR
 }

middleware/file/tree/tree.go

@@ -19,13 +19,14 @@ package tree
 import "github.com/miekg/dns"
 
 const (
-	TD234 = iota
+	td234 = iota
-	BU23
+	bu23
 )
 
 // Result is a result of a Search.
 type Result int
 
+// Various constants that indicated the type a resource returned.
 const (
 	Found Result = iota
 	NameError
@@ -34,10 +35,10 @@ const (
 )
 
 // Operation mode of the LLRB tree.
-const Mode = BU23
+const mode = bu23
 
 func init() {
-	if Mode != TD234 && Mode != BU23 {
+	if mode != td234 && mode != bu23 {
 		panic("tree: unknown mode")
 	}
 }
@@ -48,8 +49,8 @@ type Color bool
 const (
 	// Red as false give us the defined behaviour that new nodes are red. Although this
 	// is incorrect for the root node, that is resolved on the first insertion.
-	Red   Color = false
+	red   Color = false
-	Black Color = true
+	black Color = true
 )
 
 // A Node represents a node in the LLRB tree.
@@ -70,7 +71,7 @@ type Tree struct {
 // color returns the effect color of a Node. A nil node returns black.
 func (n *Node) color() Color {
 	if n == nil {
-		return Black
+		return black
 	}
 	return n.Color
 }
@@ -82,7 +83,7 @@ func (n *Node) rotateLeft() (root *Node) {
 	n.Right = root.Left
 	root.Left = n
 	root.Color = n.Color
-	n.Color = Red
+	n.Color = red
 	return
 }
 
@@ -93,7 +94,7 @@ func (n *Node) rotateRight() (root *Node) {
 	n.Left = root.Right
 	root.Right = n
 	root.Color = n.Color
-	n.Color = Red
+	n.Color = red
 	return
 }
 
@@ -108,16 +109,16 @@ func (n *Node) flipColors() {
 // fixUp ensures that black link balance is correct, that red nodes lean left,
 // and that 4 nodes are split in the case of BU23 and properly balanced in TD234.
 func (n *Node) fixUp() *Node {
-	if n.Right.color() == Red {
+	if n.Right.color() == red {
-		if Mode == TD234 && n.Right.Left.color() == Red {
+		if mode == td234 && n.Right.Left.color() == red {
 			n.Right = n.Right.rotateRight()
 		}
 		n = n.rotateLeft()
 	}
-	if n.Left.color() == Red && n.Left.Left.color() == Red {
+	if n.Left.color() == red && n.Left.Left.color() == red {
 		n = n.rotateRight()
 	}
-	if Mode == BU23 && n.Left.color() == Red && n.Right.color() == Red {
+	if mode == bu23 && n.Left.color() == red && n.Right.color() == red {
 		n.flipColors()
 	}
 	return n
@@ -125,11 +126,11 @@ func (n *Node) fixUp() *Node {
 
 func (n *Node) moveRedLeft() *Node {
 	n.flipColors()
-	if n.Right.Left.color() == Red {
+	if n.Right.Left.color() == red {
 		n.Right = n.Right.rotateRight()
 		n = n.rotateLeft()
 		n.flipColors()
-		if Mode == TD234 && n.Right.Right.color() == Red {
+		if mode == td234 && n.Right.Right.color() == red {
 			n.Right = n.Right.rotateLeft()
 		}
 	}
@@ -138,7 +139,7 @@ func (n *Node) moveRedLeft() *Node {
 
 func (n *Node) moveRedRight() *Node {
 	n.flipColors()
-	if n.Left.Left.color() == Red {
+	if n.Left.Left.color() == red {
 		n = n.rotateRight()
 		n.flipColors()
 	}
@@ -212,7 +213,7 @@ func (t *Tree) Insert(rr dns.RR) {
 	var d int
 	t.Root, d = t.Root.insert(rr)
 	t.Count += d
-	t.Root.Color = Black
+	t.Root.Color = black
 }
 
 func (n *Node) insert(rr dns.RR) (root *Node, d int) {
@@ -223,8 +224,8 @@ func (n *Node) insert(rr dns.RR) (root *Node, d int) {
 		return n, 1
 	}
 
-	if Mode == TD234 {
+	if mode == td234 {
-		if n.Left.color() == Red && n.Right.color() == Red {
+		if n.Left.color() == red && n.Right.color() == red {
 			n.flipColors()
 		}
 	}
@@ -238,15 +239,15 @@ func (n *Node) insert(rr dns.RR) (root *Node, d int) {
 		n.Right, d = n.Right.insert(rr)
 	}
 
-	if n.Right.color() == Red && n.Left.color() == Black {
+	if n.Right.color() == red && n.Left.color() == black {
 		n = n.rotateLeft()
 	}
-	if n.Left.color() == Red && n.Left.Left.color() == Red {
+	if n.Left.color() == red && n.Left.Left.color() == red {
 		n = n.rotateRight()
 	}
 
-	if Mode == BU23 {
+	if mode == bu23 {
-		if n.Left.color() == Red && n.Right.color() == Red {
+		if n.Left.color() == red && n.Right.color() == red {
 			n.flipColors()
 		}
 	}
@@ -267,14 +268,14 @@ func (t *Tree) DeleteMin() {
 	if t.Root == nil {
 		return
 	}
-	t.Root.Color = Black
+	t.Root.Color = black
 }
 
 func (n *Node) deleteMin() (root *Node, d int) {
 	if n.Left == nil {
 		return nil, -1
 	}
-	if n.Left.color() == Black && n.Left.Left.color() == Black {
+	if n.Left.color() == black && n.Left.Left.color() == black {
 		n = n.moveRedLeft()
 	}
 	n.Left, d = n.Left.deleteMin()
@@ -295,17 +296,17 @@ func (t *Tree) DeleteMax() {
 	if t.Root == nil {
 		return
 	}
-	t.Root.Color = Black
+	t.Root.Color = black
 }
 
 func (n *Node) deleteMax() (root *Node, d int) {
-	if n.Left != nil && n.Left.color() == Red {
+	if n.Left != nil && n.Left.color() == red {
 		n = n.rotateRight()
 	}
 	if n.Right == nil {
 		return nil, -1
 	}
-	if n.Right.color() == Black && n.Right.Left.color() == Black {
+	if n.Right.color() == black && n.Right.Left.color() == black {
 		n = n.moveRedRight()
 	}
 	n.Right, d = n.Right.deleteMax()
@@ -345,26 +346,26 @@ func (t *Tree) DeleteNode(rr dns.RR) {
 	if t.Root == nil {
 		return
 	}
-	t.Root.Color = Black
+	t.Root.Color = black
 }
 
 func (n *Node) delete(rr dns.RR) (root *Node, d int) {
 	if Less(n.Elem, rr.Header().Name) < 0 {
 		if n.Left != nil {
-			if n.Left.color() == Black && n.Left.Left.color() == Black {
+			if n.Left.color() == black && n.Left.Left.color() == black {
 				n = n.moveRedLeft()
 			}
 			n.Left, d = n.Left.delete(rr)
 		}
 	} else {
-		if n.Left.color() == Red {
+		if n.Left.color() == red {
 			n = n.rotateRight()
 		}
 		if n.Right == nil && Less(n.Elem, rr.Header().Name) == 0 {
 			return nil, -1
 		}
 		if n.Right != nil {
-			if n.Right.color() == Black && n.Right.Left.color() == Black {
+			if n.Right.color() == black && n.Right.Left.color() == black {
 				n = n.moveRedRight()
 			}
 			if Less(n.Elem, rr.Header().Name) == 0 {

middleware/file/wildcard_test.go

@@ -46,7 +46,7 @@ var wildcardTestCases = []test.Case{
 }
 
 func TestLookupWildcard(t *testing.T) {
-	zone, err := Parse(strings.NewReader(dbDnssexNL_signed), testzone1, "stdin")
+	zone, err := Parse(strings.NewReader(dbDnssexNLSigned), testzone1, "stdin")
 	if err != nil {
 		t.Fatalf("expect no error when reading zone, got %q", err)
 	}
@@ -85,7 +85,7 @@ func TestLookupWildcard(t *testing.T) {
 	}
 }
 
-const dbDnssexNL_signed = `
+const dbDnssexNLSigned = `
 ; File written on Tue Mar 29 21:02:24 2016
 ; dnssec_signzone version 9.10.3-P4-Ubuntu
 dnssex.nl.		1800	IN SOA	linode.atoom.net. miek.miek.nl. (

middleware/file/xfr.go

@@ -10,13 +10,12 @@ import (
 	"golang.org/x/net/context"
 )
 
-type (
+// Xfr serves up an AXFR.
-	Xfr struct {
+type Xfr struct {
-		*Zone
+	*Zone
-	}
+}
-)
 
-// Serve an AXFR (and fallback of IXFR) as well.
+// ServeDNS implements the middleware.Handler interface.
 func (x Xfr) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 	if !x.TransferAllowed(state) {

middleware/file/zone.go

@@ -15,6 +15,7 @@ import (
 	"github.com/miekg/dns"
 )
 
+// Zone defines a structure that contains all data related to a DNS zone.
 type Zone struct {
 	origin string
 	file   string
@@ -31,6 +32,7 @@ type Zone struct {
 	// TODO: shutdown watcher channel
 }
 
+// Apex contains the apex records of a zone: SOA, NS and their potential signatures.
 type Apex struct {
 	SOA    *dns.SOA
 	NS     []dns.RR
@@ -135,6 +137,7 @@ func (z *Zone) All() []dns.RR {
 	return append([]dns.RR{z.Apex.SOA}, records...)
 }
 
+// Reload reloads a zone when it is changed on disk. If z.NoRoload is true, no reloading will be done.
 func (z *Zone) Reload(shutdown chan bool) error {
 	if z.NoReload {
 		return nil

middleware/health/health.go

@@ -10,32 +10,33 @@ import (
 
 var once sync.Once
 
-type Health struct {
+type health struct {
 	Addr string
 
 	ln  net.Listener
 	mux *http.ServeMux
 }
 
-func health(w http.ResponseWriter, r *http.Request) {
+func (h *health) Startup() error {
-	io.WriteString(w, ok)
-}
-
-func (h *Health) Startup() error {
 	if h.Addr == "" {
 		h.Addr = defAddr
 	}
 
 	once.Do(func() {
-		if ln, err := net.Listen("tcp", h.Addr); err != nil {
+		ln, err := net.Listen("tcp", h.Addr)
+		if err != nil {
 			log.Printf("[ERROR] Failed to start health handler: %s", err)
 			return
-		} else {
-			h.ln = ln
 		}
+
+		h.ln = ln
+
 		h.mux = http.NewServeMux()
 
-		h.mux.HandleFunc(path, health)
+		h.mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+			io.WriteString(w, ok)
+		})
+
 		go func() {
 			http.Serve(h.ln, h.mux)
 		}()
@@ -43,7 +44,7 @@ func (h *Health) Startup() error {
 	return nil
 }
 
-func (h *Health) Shutdown() error {
+func (h *health) Shutdown() error {
 	if h.ln != nil {
 		return h.ln.Close()
 	}

middleware/health/health_test.go

@@ -10,14 +10,14 @@ import (
 func TestHealth(t *testing.T) {
 	// We use a random port instead of a fixed port like 8080 that may have been
 	// occupied by some other process.
-	health := Health{Addr: ":0"}
+	h := health{Addr: ":0"}
-	if err := health.Startup(); err != nil {
+	if err := h.Startup(); err != nil {
 		t.Fatalf("Unable to startup the health server: %v", err)
 	}
-	defer health.Shutdown()
+	defer h.Shutdown()
 
 	// Reconstruct the http address based on the port allocated by operating system.
-	address := fmt.Sprintf("http://%s%s", health.ln.Addr().String(), path)
+	address := fmt.Sprintf("http://%s%s", h.ln.Addr().String(), path)
 
 	response, err := http.Get(address)
 	if err != nil {

middleware/health/setup.go

@@ -19,9 +19,9 @@ func setup(c *caddy.Controller) error {
 		return middleware.Error("health", err)
 	}
 
-	health := &Health{Addr: addr}
+	h := &health{Addr: addr}
-	c.OnStartup(health.Startup)
+	c.OnStartup(h.Startup)
-	c.OnShutdown(health.Shutdown)
+	c.OnShutdown(h.Shutdown)
 
 	// Don't do AddMiddleware, as health is not *really* a middleware just a separate
 	// webserver running.

middleware/kubernetes/handler.go

@@ -11,6 +11,7 @@ import (
 	"golang.org/x/net/context"
 )
 
+// ServeDNS implements the middleware.Handler interface.
 func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 	if state.QClass() != dns.ClassINET {
@@ -29,7 +30,7 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 			srvPTR := &records[0]
 			m.Answer = append(m.Answer, srvPTR.NewPTR(state.QName(), ip))
 
-			m = dedup(m)
+			m = dnsutil.Dedup(m)
 			state.SizeAndDo(m)
 			m, _ = state.Scrub(m)
 			w.WriteMsg(m)
@@ -93,14 +94,14 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 	m.Answer = append(m.Answer, records...)
 	m.Extra = append(m.Extra, extra...)
 
-	m = dedup(m)
+	m = dnsutil.Dedup(m)
 	state.SizeAndDo(m)
 	m, _ = state.Scrub(m)
 	w.WriteMsg(m)
 	return dns.RcodeSuccess, nil
 }
 
-// NoData write a nodata response to the client.
+// Err writes an error response back to the client.
 func (k Kubernetes) Err(zone string, rcode int, state request.Request) (int, error) {
 	m := new(dns.Msg)
 	m.SetRcode(state.Req, rcode)
@@ -109,11 +110,3 @@ func (k Kubernetes) Err(zone string, rcode int, state request.Request) (int, err
 	state.W.WriteMsg(m)
 	return rcode, nil
 }
-
-func dedup(m *dns.Msg) *dns.Msg {
-	// TODO(miek): expensive!
-	m.Answer = dns.Dedup(m.Answer, nil)
-	m.Ns = dns.Dedup(m.Ns, nil)
-	m.Extra = dns.Dedup(m.Extra, nil)
-	return m
-}

middleware/kubernetes/kubernetes.go

@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/miekg/coredns/middleware"
-	"github.com/miekg/coredns/middleware/kubernetes/msg"
+	"github.com/miekg/coredns/middleware/etcd/msg"
 	"github.com/miekg/coredns/middleware/kubernetes/nametemplate"
 	"github.com/miekg/coredns/middleware/kubernetes/util"
 	"github.com/miekg/coredns/middleware/pkg/dnsutil"
@@ -22,6 +22,7 @@ import (
 	"k8s.io/kubernetes/pkg/labels"
 )
 
+// Kubernetes implements a middleware that connects to a Kubernetes cluster.
 type Kubernetes struct {
 	Next          middleware.Handler
 	Zones         []string
@@ -35,6 +36,8 @@ type Kubernetes struct {
 	Selector      *labels.Selector
 }
 
+// InitKubeCache initializes a new Kubernetes cache.
+// TODO(miek): is this correct?
 func (k *Kubernetes) InitKubeCache() error {
 	// For a custom api server or running outside a k8s cluster
 	// set URL in env.KUBERNETES_MASTER or set endpoint in Corefile
@@ -232,7 +235,7 @@ func (k *Kubernetes) getServiceRecordForIP(ip, name string) []msg.Service {
 const (
 	priority   = 10  // default priority when nothing is set
 	ttl        = 300 // default ttl when nothing is set
-	minTtl     = 60
+	minTTL     = 60
 	hostmaster = "hostmaster"
 	k8sTimeout = 5 * time.Second
 )

middleware/kubernetes/lookup.go

@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/miekg/coredns/middleware"
-	"github.com/miekg/coredns/middleware/kubernetes/msg"
+	"github.com/miekg/coredns/middleware/etcd/msg"
 	"github.com/miekg/coredns/middleware/pkg/dnsutil"
 	"github.com/miekg/coredns/request"
 
@@ -24,6 +24,7 @@ func (k Kubernetes) records(state request.Request, exact bool) ([]msg.Service, e
 	return services, nil
 }
 
+// A returns A records from kubernetes or an error.
 func (k Kubernetes) A(zone string, state request.Request, previousRecords []dns.RR) (records []dns.RR, err error) {
 	services, err := k.records(state, false)
 	if err != nil {
@@ -83,6 +84,7 @@ func (k Kubernetes) A(zone string, state request.Request, previousRecords []dns.
 	return records, nil
 }
 
+// AAAA returns AAAA records from kubernetes or an error.
 func (k Kubernetes) AAAA(zone string, state request.Request, previousRecords []dns.RR) (records []dns.RR, err error) {
 	services, err := k.records(state, false)
 	if err != nil {
@@ -144,7 +146,8 @@ func (k Kubernetes) AAAA(zone string, state request.Request, previousRecords []d
 }
 
 // SRV returns SRV records from kubernetes.
-// If the Target is not a name but an IP address, a name is created on the fly.
+// If the Target is not a name but an IP address, a name is created on the fly and the IP address is put in
+// the additional section.
 func (k Kubernetes) SRV(zone string, state request.Request) (records []dns.RR, extra []dns.RR, err error) {
 	services, err := k.records(state, false)
 	if err != nil {
@@ -226,21 +229,22 @@ func (k Kubernetes) SRV(zone string, state request.Request) (records []dns.RR, e
 	return records, extra, nil
 }
 
-// Returning MX records from kubernetes not implemented.
+// MX returns MX records from kubernetes. Not implemented!
 func (k Kubernetes) MX(zone string, state request.Request) (records []dns.RR, extra []dns.RR, err error) {
 	return nil, nil, err
 }
 
-// Returning CNAME records from kubernetes not implemented.
+// CNAME returns CNAME records from kubernetes. Not implemented!
 func (k Kubernetes) CNAME(zone string, state request.Request) (records []dns.RR, err error) {
 	return nil, err
 }
 
-// Returning TXT records from kubernetes not implemented.
+// TXT returns TXT records from kubernetes. Not implemented!
 func (k Kubernetes) TXT(zone string, state request.Request) (records []dns.RR, err error) {
 	return nil, err
 }
 
+// NS returns NS records from kubernetes.
 func (k Kubernetes) NS(zone string, state request.Request) (records, extra []dns.RR, err error) {
 	// NS record for this zone live in a special place, ns.dns.<zone>. Fake our lookup.
 	// only a tad bit fishy...
@@ -273,7 +277,7 @@ func (k Kubernetes) NS(zone string, state request.Request) (records, extra []dns
 	return records, extra, nil
 }
 
-// SOA Record returns a SOA record.
+// SOA Record returns a SOA record from kubernetes.
 func (k Kubernetes) SOA(zone string, state request.Request) *dns.SOA {
 	header := dns.RR_Header{Name: zone, Rrtype: dns.TypeSOA, Ttl: 300, Class: dns.ClassINET}
 	return &dns.SOA{Hdr: header,
@@ -287,6 +291,7 @@ func (k Kubernetes) SOA(zone string, state request.Request) *dns.SOA {
 	}
 }
 
+// PTR Record returns PTR records from kubernetes.
 func (k Kubernetes) PTR(zone string, state request.Request) ([]dns.RR, error) {
 	reverseIP := dnsutil.ExtractAddressFromReverse(state.Name())
 	if reverseIP == "" {

middleware/kubernetes/msg/service.go

@@ -1,171 +0,0 @@
-package msg
-
-import (
-	"net"
-	"strings"
-
-	"github.com/miekg/dns"
-)
-
-// This *is* the rdata from a SRV record, but with a twist.
-// Host (Target in SRV) must be a domain name, but if it looks like an IP
-// address (4/6), we will treat it like an IP address.
-type Service struct {
-	Host     string `json:"host,omitempty"`
-	Port     int    `json:"port,omitempty"`
-	Priority int    `json:"priority,omitempty"`
-	Weight   int    `json:"weight,omitempty"`
-	Text     string `json:"text,omitempty"`
-	Mail     bool   `json:"mail,omitempty"` // Be an MX record. Priority becomes Preference.
-	Ttl      uint32 `json:"ttl,omitempty"`
-
-	// When a SRV record with a "Host: IP-address" is added, we synthesize
-	// a srv.Target domain name.  Normally we convert the full Key where
-	// the record lives to a DNS name and use this as the srv.Target.  When
-	// TargetStrip > 0 we strip the left most TargetStrip labels from the
-	// DNS name.
-	TargetStrip int `json:"targetstrip,omitempty"`
-
-	// Group is used to group (or *not* to group) different services
-	// together. Services with an identical Group are returned in the same
-	// answer.
-	Group string `json:"group,omitempty"`
-
-	// Etcd key where we found this service and ignored from json un-/marshalling
-	Key string `json:"-"`
-}
-
-// NewSRV returns a new SRV record based on the Service.
-func (s *Service) NewSRV(name string, weight uint16) *dns.SRV {
-	host := targetStrip(dns.Fqdn(s.Host), s.TargetStrip)
-
-	return &dns.SRV{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeSRV, Class: dns.ClassINET, Ttl: s.Ttl},
-		Priority: uint16(s.Priority), Weight: weight, Port: uint16(s.Port), Target: dns.Fqdn(host)}
-}
-
-// NewMX returns a new MX record based on the Service.
-func (s *Service) NewMX(name string) *dns.MX {
-	host := targetStrip(dns.Fqdn(s.Host), s.TargetStrip)
-
-	return &dns.MX{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeMX, Class: dns.ClassINET, Ttl: s.Ttl},
-		Preference: uint16(s.Priority), Mx: host}
-}
-
-// NewA returns a new A record based on the Service.
-func (s *Service) NewA(name string, ip net.IP) *dns.A {
-	return &dns.A{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.Ttl}, A: ip}
-}
-
-// NewAAAA returns a new AAAA record based on the Service.
-func (s *Service) NewAAAA(name string, ip net.IP) *dns.AAAA {
-	return &dns.AAAA{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.Ttl}, AAAA: ip}
-}
-
-// NewCNAME returns a new CNAME record based on the Service.
-func (s *Service) NewCNAME(name string, target string) *dns.CNAME {
-	return &dns.CNAME{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeCNAME, Class: dns.ClassINET, Ttl: s.Ttl}, Target: dns.Fqdn(target)}
-}
-
-// NewTXT returns a new TXT record based on the Service.
-func (s *Service) NewTXT(name string) *dns.TXT {
-	return &dns.TXT{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: s.Ttl}, Txt: split255(s.Text)}
-}
-
-// NewNS returns a new NS record based on the Service.
-func (s *Service) NewNS(name string) *dns.NS {
-	host := targetStrip(dns.Fqdn(s.Host), s.TargetStrip)
-	return &dns.NS{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeNS, Class: dns.ClassINET, Ttl: s.Ttl}, Ns: host}
-}
-
-// NewPTR returns a new PTR record based on the Service.
-func (s *Service) NewPTR(name string, target string) *dns.PTR {
-	return &dns.PTR{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypePTR, Class: dns.ClassINET, Ttl: s.Ttl}, Ptr: dns.Fqdn(target)}
-}
-
-// Group checks the services in sx, it looks for a Group attribute on the shortest
-// keys. If there are multiple shortest keys *and* the group attribute disagrees (and
-// is not empty), we don't consider it a group.
-// If a group is found, only services with *that* group (or no group) will be returned.
-func Group(sx []Service) []Service {
-	if len(sx) == 0 {
-		return sx
-	}
-
-	// Shortest key with group attribute sets the group for this set.
-	group := sx[0].Group
-	slashes := strings.Count(sx[0].Key, "/")
-	length := make([]int, len(sx))
-	for i, s := range sx {
-		x := strings.Count(s.Key, "/")
-		length[i] = x
-		if x < slashes {
-			if s.Group == "" {
-				break
-			}
-			slashes = x
-			group = s.Group
-		}
-	}
-
-	if group == "" {
-		return sx
-	}
-
-	ret := []Service{} // with slice-tricks in sx we can prolly save this allocation (TODO)
-
-	for i, s := range sx {
-		if s.Group == "" {
-			ret = append(ret, s)
-			continue
-		}
-
-		// Disagreement on the same level
-		if length[i] == slashes && s.Group != group {
-			return sx
-		}
-
-		if s.Group == group {
-			ret = append(ret, s)
-		}
-	}
-	return ret
-}
-
-// Split255 splits a string into 255 byte chunks.
-func split255(s string) []string {
-	if len(s) < 255 {
-		return []string{s}
-	}
-	sx := []string{}
-	p, i := 0, 255
-	for {
-		if i <= len(s) {
-			sx = append(sx, s[p:i])
-		} else {
-			sx = append(sx, s[p:])
-			break
-
-		}
-		p, i = p+255, i+255
-	}
-
-	return sx
-}
-
-// targetStrip strips "targetstrip" labels from the left side of the fully qualified name.
-func targetStrip(name string, targetStrip int) string {
-	if targetStrip == 0 {
-		return name
-	}
-
-	offset, end := 0, false
-	for i := 0; i < targetStrip; i++ {
-		offset, end = dns.NextLabel(name, offset)
-	}
-	if end {
-		// We overshot the name, use the orignal one.
-		offset = 0
-	}
-	name = name[offset:]
-	return name
-}

middleware/kubernetes/msg/service_test.go

@@ -1,125 +0,0 @@
-package msg
-
-import "testing"
-
-func TestSplit255(t *testing.T) {
-	xs := split255("abc")
-	if len(xs) != 1 && xs[0] != "abc" {
-		t.Errorf("Failure to split abc")
-	}
-	s := ""
-	for i := 0; i < 255; i++ {
-		s += "a"
-	}
-	xs = split255(s)
-	if len(xs) != 1 && xs[0] != s {
-		t.Errorf("failure to split 255 char long string")
-	}
-	s += "b"
-	xs = split255(s)
-	if len(xs) != 2 || xs[1] != "b" {
-		t.Errorf("failure to split 256 char long string: %d", len(xs))
-	}
-	for i := 0; i < 255; i++ {
-		s += "a"
-	}
-	xs = split255(s)
-	if len(xs) != 3 || xs[2] != "a" {
-		t.Errorf("failure to split 510 char long string: %d", len(xs))
-	}
-}
-
-func TestGroup(t *testing.T) {
-	// Key are in the wrong order, but for this test it does not matter.
-	sx := Group(
-		[]Service{
-			{Host: "127.0.0.1", Group: "g1", Key: "b/sub/dom1/skydns/test"},
-			{Host: "127.0.0.2", Group: "g2", Key: "a/dom1/skydns/test"},
-		},
-	)
-	// Expecting to return the shortest key with a Group attribute.
-	if len(sx) != 1 {
-		t.Fatalf("failure to group zeroth set: %v", sx)
-	}
-	if sx[0].Key != "a/dom1/skydns/test" {
-		t.Fatalf("failure to group zeroth set: %v, wrong Key", sx)
-	}
-
-	// Groups disagree, so we will not do anything.
-	sx = Group(
-		[]Service{
-			{Host: "server1", Group: "g1", Key: "region1/skydns/test"},
-			{Host: "server2", Group: "g2", Key: "region1/skydns/test"},
-		},
-	)
-	if len(sx) != 2 {
-		t.Fatalf("failure to group first set: %v", sx)
-	}
-
-	// Group is g1, include only the top-level one.
-	sx = Group(
-		[]Service{
-			{Host: "server1", Group: "g1", Key: "a/dom/region1/skydns/test"},
-			{Host: "server2", Group: "g2", Key: "a/subdom/dom/region1/skydns/test"},
-		},
-	)
-	if len(sx) != 1 {
-		t.Fatalf("failure to group second set: %v", sx)
-	}
-
-	// Groupless services must be included.
-	sx = Group(
-		[]Service{
-			{Host: "server1", Group: "g1", Key: "a/dom/region1/skydns/test"},
-			{Host: "server2", Group: "g2", Key: "a/subdom/dom/region1/skydns/test"},
-			{Host: "server2", Group: "", Key: "b/subdom/dom/region1/skydns/test"},
-		},
-	)
-	if len(sx) != 2 {
-		t.Fatalf("failure to group third set: %v", sx)
-	}
-
-	// Empty group on the highest level: include that one also.
-	sx = Group(
-		[]Service{
-			{Host: "server1", Group: "g1", Key: "a/dom/region1/skydns/test"},
-			{Host: "server1", Group: "", Key: "b/dom/region1/skydns/test"},
-			{Host: "server2", Group: "g2", Key: "a/subdom/dom/region1/skydns/test"},
-		},
-	)
-	if len(sx) != 2 {
-		t.Fatalf("failure to group fourth set: %v", sx)
-	}
-
-	// Empty group on the highest level: include that one also, and the rest.
-	sx = Group(
-		[]Service{
-			{Host: "server1", Group: "g5", Key: "a/dom/region1/skydns/test"},
-			{Host: "server1", Group: "", Key: "b/dom/region1/skydns/test"},
-			{Host: "server2", Group: "g5", Key: "a/subdom/dom/region1/skydns/test"},
-		},
-	)
-	if len(sx) != 3 {
-		t.Fatalf("failure to group fith set: %v", sx)
-	}
-
-	// One group.
-	sx = Group(
-		[]Service{
-			{Host: "server1", Group: "g6", Key: "a/dom/region1/skydns/test"},
-		},
-	)
-	if len(sx) != 1 {
-		t.Fatalf("failure to group sixth set: %v", sx)
-	}
-
-	// No group, once service
-	sx = Group(
-		[]Service{
-			{Host: "server1", Key: "a/dom/region1/skydns/test"},
-		},
-	)
-	if len(sx) != 1 {
-		t.Fatalf("failure to group seventh set: %v", sx)
-	}
-}

middleware/kubernetes/nametemplate/nametemplate.go

@@ -60,6 +60,7 @@ var requiredSymbols = []string{
 //		 Where the query string is longer than the template, need to define which
 //		 symbol consumes the other segments. Most likely this would be the servicename.
 //		 Also consider how to handle static strings in the format template.
+
 type NameTemplate struct {
 	formatString string
 	splitFormat  []string
@@ -105,11 +106,11 @@ func (t *NameTemplate) SetTemplate(s string) error {
 //       step down the stack to find the right element.
 
 func (t *NameTemplate) GetZoneFromSegmentArray(segments []string) string {
-	if index, ok := t.Element["zone"]; !ok {
+	index, ok := t.Element["zone"]
+	if !ok {
 		return ""
-	} else {
-		return strings.Join(segments[index:len(segments)], ".")
 	}
+	return strings.Join(segments[index:len(segments)], ".")
 }
 
 func (t *NameTemplate) GetNamespaceFromSegmentArray(segments []string) string {
@@ -132,11 +133,11 @@ func (t *NameTemplate) GetTypeFromSegmentArray(segments []string) string {
 }
 
 func (t *NameTemplate) GetSymbolFromSegmentArray(symbol string, segments []string) string {
-	if index, ok := t.Element[symbol]; !ok {
+	index, ok := t.Element[symbol]
+	if !ok {
 		return ""
-	} else {
-		return segments[index]
 	}
+	return segments[index]
 }
 
 // GetRecordNameFromNameValues returns the string produced by applying the
@@ -164,6 +165,7 @@ func (t *NameTemplate) GetRecordNameFromNameValues(values NameValues) string {
 }
 
 func (t *NameTemplate) IsValid() bool {
+	// This is *only* used in a test, for the test this should be a private method.
 	result := true
 
 	// Ensure that all requiredSymbols are found in NameTemplate

middleware/loadbalance/handler.go

@@ -15,6 +15,6 @@ type RoundRobin struct {
 
 // ServeDNS implements the middleware.Handler interface.
 func (rr RoundRobin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
-	wrr := NewRoundRobinResponseWriter(w)
+	wrr := &RoundRobinResponseWriter{w}
 	return rr.Next.ServeDNS(ctx, wrr, r)
 }

middleware/loadbalance/loadbalance.go

@@ -6,14 +6,12 @@ import (
 	"github.com/miekg/dns"
 )
 
+// RoundRobinResponseWriter is a response writer that shuffles A and AAAA records.
 type RoundRobinResponseWriter struct {
 	dns.ResponseWriter
 }
 
-func NewRoundRobinResponseWriter(w dns.ResponseWriter) *RoundRobinResponseWriter {
+// WriteMsg implements the dns.ResponseWriter interface.
-	return &RoundRobinResponseWriter{w}
-}
-
 func (r *RoundRobinResponseWriter) WriteMsg(res *dns.Msg) error {
 	if res.Rcode != dns.RcodeSuccess {
 		return r.ResponseWriter.WriteMsg(res)
@@ -63,13 +61,15 @@ func roundRobin(in []dns.RR) []dns.RR {
 	return out
 }
 
-// Should we pack and unpack here to fiddle with the packet... Not likely.
+// Write implements the dns.ResponseWriter interface.
 func (r *RoundRobinResponseWriter) Write(buf []byte) (int, error) {
+	// Should we pack and unpack here to fiddle with the packet... Not likely.
 	log.Printf("[WARNING] RoundRobin called with Write: no shuffling records")
 	n, err := r.ResponseWriter.Write(buf)
 	return n, err
 }
 
+// Hijack implements the dns.ResponseWriter interface.
 func (r *RoundRobinResponseWriter) Hijack() {
 	r.ResponseWriter.Hijack()
 	return

middleware/log/log.go

@@ -23,6 +23,7 @@ type Logger struct {
 	ErrorFunc func(dns.ResponseWriter, *dns.Msg, int) // failover error handler
 }
 
+// ServeDNS implements the middleware.Handler interface.
 func (l Logger) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 	for _, rule := range l.Rules {

middleware/metrics/handler.go

@@ -12,6 +12,7 @@ import (
 	"golang.org/x/net/context"
 )
 
+// ServeDNS implements the Handler interface.
 func (m Metrics) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 

middleware/metrics/metrics.go

@@ -34,16 +34,19 @@ type Metrics struct {
 	ZoneNames []string
 }
 
-func (m *Metrics) Startup() error {
+// OnStartup sets up the metrics on startup.
+func (m *Metrics) OnStartup() error {
 	m.Once.Do(func() {
 		define()
 
-		if ln, err := net.Listen("tcp", m.Addr); err != nil {
+		ln, err := net.Listen("tcp", m.Addr)
+		if err != nil {
 			log.Printf("[ERROR] Failed to start metrics handler: %s", err)
 			return
-		} else {
-			m.ln = ln
 		}
+
+		m.ln = ln
+
 		m.mux = http.NewServeMux()
 
 		prometheus.MustRegister(requestCount)
@@ -66,7 +69,8 @@ func (m *Metrics) Startup() error {
 	return nil
 }
 
-func (m *Metrics) Shutdown() error {
+// OnShutdown tears down the metrics on shutdown.
+func (m *Metrics) OnShutdown() error {
 	if m.ln != nil {
 		return m.ln.Close()
 	}

middleware/metrics/setup.go

@@ -28,8 +28,8 @@ func setup(c *caddy.Controller) error {
 	})
 
 	metricsOnce.Do(func() {
-		c.OnStartup(m.Startup)
+		c.OnStartup(m.OnStartup)
-		c.OnShutdown(m.Shutdown)
+		c.OnShutdown(m.OnShutdown)
 	})
 
 	return nil

middleware/pkg/dnsutil/dedup.go

@@ -0,0 +1,12 @@
+package dnsutil
+
+import "github.com/miekg/dns"
+
+// Dedup de-duplicates a message.
+func Dedup(m *dns.Msg) *dns.Msg {
+	// TODO(miek): expensive!
+	m.Answer = dns.Dedup(m.Answer, nil)
+	m.Ns = dns.Dedup(m.Ns, nil)
+	m.Extra = dns.Dedup(m.Extra, nil)
+	return m
+}

middleware/pprof/pprof.go

@@ -7,12 +7,12 @@ import (
 	pp "net/http/pprof"
 )
 
-type Handler struct {
+type handler struct {
 	ln  net.Listener
 	mux *http.ServeMux
 }
 
-func (h *Handler) Startup() error {
+func (h *handler) Startup() error {
 	ln, err := net.Listen("tcp", addr)
 	if err != nil {
 		log.Printf("[ERROR] Failed to start pprof handler: %s", err)
@@ -34,7 +34,7 @@ func (h *Handler) Startup() error {
 	return nil
 }
 
-func (h *Handler) Shutdown() error {
+func (h *handler) Shutdown() error {
 	if h.ln != nil {
 		return h.ln.Close()
 	}

middleware/pprof/setup.go

@@ -29,10 +29,10 @@ func setup(c *caddy.Controller) error {
 		found = true
 	}
 
-	handler := &Handler{}
+	h := &handler{}
 	pprofOnce.Do(func() {
-		c.OnStartup(handler.Startup)
+		c.OnStartup(h.Startup)
-		c.OnShutdown(handler.Shutdown)
+		c.OnShutdown(h.Shutdown)
 	})
 
 	return nil

middleware/proxy/upstream.go

@@ -38,6 +38,7 @@ type staticUpstream struct {
 	IgnoredSubDomains []string
 	options           Options
 }
+
 type Options struct {
 	Ecs []*net.IPNet // EDNS0 CLIENT SUBNET address (v4/v6) to add in CIDR notaton.
 }

middleware/rewrite/reverter.go

@@ -2,7 +2,7 @@ package rewrite
 
 import "github.com/miekg/dns"
 
-// ResponseRevert reverses the operations done on the question section of a packet.
+// ResponseReverter reverses the operations done on the question section of a packet.
 // This is need because the client will otherwise disregards the response, i.e.
 // dig will complain with ';; Question section mismatch: got miek.nl/HINFO/IN'
 type ResponseReverter struct {
@@ -10,6 +10,7 @@ type ResponseReverter struct {
 	original dns.Question
 }
 
+// NewResponseReverter returns a pointer to a new ResponseReverter.
 func NewResponseReverter(w dns.ResponseWriter, r *dns.Msg) *ResponseReverter {
 	return &ResponseReverter{
 		ResponseWriter: w,

middleware/rewrite/rewrite.go

@@ -30,7 +30,7 @@ type Rewrite struct {
 	noRevert bool
 }
 
-// ServeHTTP implements the middleware.Handler interface.
+// ServeDNS implements the middleware.Handler interface.
 func (rw Rewrite) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	wr := NewResponseReverter(w, r)
 	for _, rule := range rw.Rules {

middleware/rewrite/setup.go

@@ -1,7 +1,6 @@
 package rewrite
 
 import (
-	"strconv"
 	"strings"
 
 	"github.com/miekg/coredns/core/dnsserver"
@@ -36,73 +35,76 @@ func rewriteParse(c *caddy.Controller) ([]Rule, error) {
 
 	for c.Next() {
 		var rule Rule
-		var err error
+		/*
-		var base = "."
+			var base = "."
-		var pattern, to string
+			var err error
-		var status int
+			var pattern, to string
-		var ext []string
+			var status int
+			var ifs []If
+			var ext []string
+		*/
 
 		args := c.RemainingArgs()
 
-		var ifs []If
-
 		switch len(args) {
 		case 1:
-			base = args[0]
+			/*
-			fallthrough
+				base = args[0]
+				fallthrough
+			*/
 		case 0:
-			for c.NextBlock() {
+			/*
-				switch c.Val() {
+				for c.NextBlock() {
-				case "r", "regexp":
+					switch c.Val() {
-					if !c.NextArg() {
+					case "r", "regexp":
+						if !c.NextArg() {
+							return nil, c.ArgErr()
+						}
+						pattern = c.Val()
+					case "to":
+						args1 := c.RemainingArgs()
+						if len(args1) == 0 {
+							return nil, c.ArgErr()
+						}
+						to = strings.Join(args1, " ")
+					case "ext": // TODO(miek): fix or remove
+						args1 := c.RemainingArgs()
+						if len(args1) == 0 {
+							return nil, c.ArgErr()
+						}
+						ext = args1
+					case "if":
+						args1 := c.RemainingArgs()
+						if len(args1) != 3 {
+							return nil, c.ArgErr()
+						}
+						ifCond, err := NewIf(args1[0], args1[1], args1[2])
+						if err != nil {
+							return nil, err
+						}
+						ifs = append(ifs, ifCond)
+					case "status": // TODO(miek): fix or remove
+						if !c.NextArg() {
+							return nil, c.ArgErr()
+						}
+						status, _ = strconv.Atoi(c.Val())
+						if status < 200 || (status > 299 && status < 400) || status > 499 {
+							return nil, c.Err("status must be 2xx or 4xx")
+						}
+					default:
 						return nil, c.ArgErr()
 					}
-					pattern = c.Val()
+				}
-				case "to":
+				// ensure to or status is specified
-					args1 := c.RemainingArgs()
+				if to == "" && status == 0 {
-					if len(args1) == 0 {
-						return nil, c.ArgErr()
-					}
-					to = strings.Join(args1, " ")
-				case "ext": // TODO(miek): fix or remove
-					args1 := c.RemainingArgs()
-					if len(args1) == 0 {
-						return nil, c.ArgErr()
-					}
-					ext = args1
-				case "if":
-					args1 := c.RemainingArgs()
-					if len(args1) != 3 {
-						return nil, c.ArgErr()
-					}
-					ifCond, err := NewIf(args1[0], args1[1], args1[2])
-					if err != nil {
-						return nil, err
-					}
-					ifs = append(ifs, ifCond)
-				case "status": // TODO(miek): fix or remove
-					if !c.NextArg() {
-						return nil, c.ArgErr()
-					}
-					status, _ = strconv.Atoi(c.Val())
-					if status < 200 || (status > 299 && status < 400) || status > 499 {
-						return nil, c.Err("status must be 2xx or 4xx")
-					}
-				default:
 					return nil, c.ArgErr()
 				}
-			}
+				// TODO(miek): complex rules
-			// ensure to or status is specified
+				if rule, err = NewComplexRule(base, pattern, to, status, ext, ifs); err != nil {
-			if to == "" && status == 0 {
+					return nil, err
-				return nil, c.ArgErr()
+				}
-			}
+				regexpRules = append(regexpRules, rule)
-			// TODO(miek): complex rules
+			*/
-			base, pattern, to, status, ext, ifs = base, pattern, to, status, ext, ifs
-			err = err
-			// if rule, err = NewComplexRule(base, pattern, to, status, ext, ifs); err != nil {
-			// return nil, err
-			// }
-			regexpRules = append(regexpRules, rule)
 
 		// the only unhandled case is 2 and above
 		default:

middleware/secondary/secondary.go

@@ -2,6 +2,8 @@ package secondary
 
 import "github.com/miekg/coredns/middleware/file"
 
+// Secondary implements a secondary middleware that allows CoreDNS to retrieve (via AXFR)
+// zone information from a primary server.
 type Secondary struct {
 	file.File
 }

middleware/test/helpers.go

@@ -7,21 +7,26 @@ import (
 	"golang.org/x/net/context"
 )
 
-type Sect int
+type sect int
 
 const (
-	Answer Sect = iota
+	// Answer is the answer section in an Msg.
+	Answer sect = iota
+	// Ns is the authrotitative section in an Msg.
 	Ns
+	// Extra is the additional section in an Msg.
 	Extra
 )
 
+// RRSet represents a list of RRs.
 type RRSet []dns.RR
 
 func (p RRSet) Len() int           { return len(p) }
 func (p RRSet) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
 func (p RRSet) Less(i, j int) bool { return p[i].String() < p[j].String() }
 
-// If the TTL of a record is 303 we don't care what the TTL is.
+// Case represents a test case that encapsulates various data from a query and response.
+// Note that is the TTL of a record is 303 we don't compare it with the TTL.
 type Case struct {
 	Qname  string
 	Qtype  uint16
@@ -32,6 +37,7 @@ type Case struct {
 	Extra  []dns.RR
 }
 
+// Msg returns a *dns.Msg embedded in c.
 func (c Case) Msg() *dns.Msg {
 	m := new(dns.Msg)
 	m.SetQuestion(dns.Fqdn(c.Qname), c.Qtype)
@@ -46,19 +52,43 @@ func (c Case) Msg() *dns.Msg {
 	return m
 }
 
-func A(rr string) *dns.A           { r, _ := dns.NewRR(rr); return r.(*dns.A) }
+// A returns an A record from rr. It panics on errors.
-func AAAA(rr string) *dns.AAAA     { r, _ := dns.NewRR(rr); return r.(*dns.AAAA) }
+func A(rr string) *dns.A { r, _ := dns.NewRR(rr); return r.(*dns.A) }
-func CNAME(rr string) *dns.CNAME   { r, _ := dns.NewRR(rr); return r.(*dns.CNAME) }
+
-func SRV(rr string) *dns.SRV       { r, _ := dns.NewRR(rr); return r.(*dns.SRV) }
+// AAAA returns an AAAA record from rr. It panics on errors.
-func SOA(rr string) *dns.SOA       { r, _ := dns.NewRR(rr); return r.(*dns.SOA) }
+func AAAA(rr string) *dns.AAAA { r, _ := dns.NewRR(rr); return r.(*dns.AAAA) }
-func NS(rr string) *dns.NS         { r, _ := dns.NewRR(rr); return r.(*dns.NS) }
+
-func PTR(rr string) *dns.PTR       { r, _ := dns.NewRR(rr); return r.(*dns.PTR) }
+// CNAME returns a CNAME record from rr. It panics on errors.
-func TXT(rr string) *dns.TXT       { r, _ := dns.NewRR(rr); return r.(*dns.TXT) }
+func CNAME(rr string) *dns.CNAME { r, _ := dns.NewRR(rr); return r.(*dns.CNAME) }
-func MX(rr string) *dns.MX         { r, _ := dns.NewRR(rr); return r.(*dns.MX) }
+
-func RRSIG(rr string) *dns.RRSIG   { r, _ := dns.NewRR(rr); return r.(*dns.RRSIG) }
+// SRV returns a SRV record from rr. It panics on errors.
-func NSEC(rr string) *dns.NSEC     { r, _ := dns.NewRR(rr); return r.(*dns.NSEC) }
+func SRV(rr string) *dns.SRV { r, _ := dns.NewRR(rr); return r.(*dns.SRV) }
+
+// SOA returns a SOA record from rr. It panics on errors.
+func SOA(rr string) *dns.SOA { r, _ := dns.NewRR(rr); return r.(*dns.SOA) }
+
+// NS returns an NS record from rr. It panics on errors.
+func NS(rr string) *dns.NS { r, _ := dns.NewRR(rr); return r.(*dns.NS) }
+
+// PTR returns a PTR record from rr. It panics on errors.
+func PTR(rr string) *dns.PTR { r, _ := dns.NewRR(rr); return r.(*dns.PTR) }
+
+// TXT returns a TXT record from rr. It panics on errors.
+func TXT(rr string) *dns.TXT { r, _ := dns.NewRR(rr); return r.(*dns.TXT) }
+
+// MX returns an MX record from rr. It panics on errors.
+func MX(rr string) *dns.MX { r, _ := dns.NewRR(rr); return r.(*dns.MX) }
+
+// RRSIG returns an RRSIG record from rr. It panics on errors.
+func RRSIG(rr string) *dns.RRSIG { r, _ := dns.NewRR(rr); return r.(*dns.RRSIG) }
+
+// NSEC returns an NSEC record from rr. It panics on errors.
+func NSEC(rr string) *dns.NSEC { r, _ := dns.NewRR(rr); return r.(*dns.NSEC) }
+
+// DNSKEY returns a DNSKEY record from rr. It panics on errors.
 func DNSKEY(rr string) *dns.DNSKEY { r, _ := dns.NewRR(rr); return r.(*dns.DNSKEY) }
 
+// OPT returns an OPT record with UDP buffer size set to bufsize and the DO bit set to do.
 func OPT(bufsize int, do bool) *dns.OPT {
 	o := new(dns.OPT)
 	o.Hdr.Name = "."
@@ -71,6 +101,7 @@ func OPT(bufsize int, do bool) *dns.OPT {
 	return o
 }
 
+// Header test if the header in resp matches the header as defined in tc.
 func Header(t *testing.T, tc Case, resp *dns.Msg) bool {
 	if resp.Rcode != tc.Rcode {
 		t.Errorf("rcode is %q, expected %q", dns.RcodeToString[resp.Rcode], dns.RcodeToString[tc.Rcode])
@@ -92,9 +123,10 @@ func Header(t *testing.T, tc Case, resp *dns.Msg) bool {
 	return true
 }
 
-func Section(t *testing.T, tc Case, sect Sect, rr []dns.RR) bool {
+// Section tests if the the section in tc matches rr.
+func Section(t *testing.T, tc Case, sec sect, rr []dns.RR) bool {
 	section := []dns.RR{}
-	switch sect {
+	switch sec {
 	case 0:
 		section = tc.Answer
 	case 1:
@@ -224,7 +256,7 @@ func Section(t *testing.T, tc Case, sect Sect, rr []dns.RR) bool {
 	return true
 }
 
-// ErrorHanlder returns a Handler that returns ServerFailure error when called.
+// ErrorHandler returns a Handler that returns ServerFailure error when called.
 func ErrorHandler() Handler {
 	return HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 		m := new(dns.Msg)
@@ -242,11 +274,13 @@ func NextHandler(rcode int, err error) Handler {
 }
 
 // Copied here to prevent an import cycle, so that we can define to above handlers.
+
 type (
 	// HandlerFunc is a convenience type like dns.HandlerFunc, except
 	// ServeDNS returns an rcode and an error.
 	HandlerFunc func(context.Context, dns.ResponseWriter, *dns.Msg) (int, error)
 
+	// Handler interface defines a middleware.
 	Handler interface {
 		ServeDNS(context.Context, dns.ResponseWriter, *dns.Msg) (int, error)
 	}

middleware/test/responsewriter.go

@@ -25,9 +25,20 @@ func (t *ResponseWriter) RemoteAddr() net.Addr {
 	return &net.UDPAddr{IP: ip, Port: port, Zone: ""}
 }
 
-func (t *ResponseWriter) WriteMsg(m *dns.Msg) error     { return nil }
+// WriteMsg implement dns.ResponseWriter interface.
+func (t *ResponseWriter) WriteMsg(m *dns.Msg) error { return nil }
+
+// Write implement dns.ResponseWriter interface.
 func (t *ResponseWriter) Write(buf []byte) (int, error) { return len(buf), nil }
-func (t *ResponseWriter) Close() error                  { return nil }
+
-func (t *ResponseWriter) TsigStatus() error             { return nil }
+// Close implement dns.ResponseWriter interface.
-func (t *ResponseWriter) TsigTimersOnly(bool)           { return }
+func (t *ResponseWriter) Close() error { return nil }
-func (t *ResponseWriter) Hijack()                       { return }
+
+// TsigStatus implement dns.ResponseWriter interface.
+func (t *ResponseWriter) TsigStatus() error { return nil }
+
+// TsigTimersOnly implement dns.ResponseWriter interface.
+func (t *ResponseWriter) TsigTimersOnly(bool) { return }
+
+// Hijack implement dns.ResponseWriter interface.
+func (t *ResponseWriter) Hijack() { return }

middleware/test/server.go

@@ -9,6 +9,7 @@ import (
 	"github.com/miekg/dns"
 )
 
+// TCPServer starts a DNS server with a TCP listener on laddr.
 func TCPServer(t *testing.T, laddr string) (*dns.Server, string, error) {
 	l, err := net.Listen("tcp", laddr)
 	if err != nil {
@@ -30,6 +31,7 @@ func TCPServer(t *testing.T, laddr string) (*dns.Server, string, error) {
 	return server, l.Addr().String(), nil
 }
 
+// UDPServer starts a DNS server with an UDP listener on laddr.
 func UDPServer(t *testing.T, laddr string) (*dns.Server, string, error) {
 	pc, err := net.ListenPacket("udp", laddr)
 	if err != nil {

middleware/whoami/whoami.go

@@ -11,10 +11,13 @@ import (
 	"golang.org/x/net/context"
 )
 
+// Whoami is a middleware that returns your IP address, port and the protocol used for connecting
+// to CoreDNS.
 type Whoami struct {
 	Next middleware.Handler
 }
 
+// ServeDNS implements the middleware.Handler interface.
 func (wh Whoami) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}