Run golint and go vet (#276)

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

middleware/pkg/rcode/rcode.go

@@ -6,6 +6,8 @@ import (
 	"github.com/miekg/dns"
 )
 
+// ToString convert the rcode to the offical DNS string, or to "RCODE"+value if the RCODE
+// value is unknown.
 func ToString(rcode int) string {
 	if str, ok := dns.RcodeToString[rcode]; ok {
 		return str

middleware/pkg/response/classify.go

@@ -2,14 +2,20 @@ package response
 
 import "github.com/miekg/dns"
 
+// Type is the type of the message
 type Type int
 
 const (
-	Success    Type = iota
-	NameError       // NXDOMAIN in header, SOA in auth.
-	NoData          // NOERROR in header, SOA in auth.
-	Delegation      // NOERROR in header, NS in auth, optionally fluff in additional (not checked).
-	OtherError      // Don't cache these.
+	// Success indicates a positive reply
+	Success Type = iota
+	// NameError is a NXDOMAIN in header, SOA in auth.
+	NameError
+	// NoData indicated name found, but not the type: NOERROR in header, SOA in auth.
+	NoData
+	// Delegation is a msg with a pointer to another nameserver: NOERROR in header, NS in auth, optionally fluff in additional (not checked).
+	Delegation
+	// OtherError indicated any other error: don't cache these.
+	OtherError
 )
 
 // Classify classifies a message, it returns the Type.

middleware/pkg/storage/fs.go

@@ -25,7 +25,7 @@ type dir http.Dir
 //
 // CoreDir will default to "$HOME/.coredns" on Unix, but it's location can be overriden with the COREDNSPATH
 // environment variable.
-var CoreDir dir = dir(fsPath())
+var CoreDir = dir(fsPath())
 
 func (d dir) Zone(z string) dir {
 	if z != "." && z[len(z)-2] == '.' {

middleware/pkg/storage/fs_test.go

@@ -7,7 +7,7 @@ import (
 	"testing"
 )
 
-func TestfsPath(t *testing.T) {
+func TestFsPath(t *testing.T) {
 	if actual := fsPath(); !strings.HasSuffix(actual, ".coredns") {
 		t.Errorf("Expected path to be a .coredns folder, got: %v", actual)
 	}