Add pkg/fall for Fallthrough (#1355)

* Add pkg/fall for Fallthrough

Move this into it's own package to facilitate tests. Important bug
was fixed: make the names fully qualified.

Add fall package to hosts, reverse, etcd, and fix kubernetes and any
tests. The k8s tests are still as-is, might need a future cleanup.

plugin/kubernetes/handler.go

@@ -59,7 +59,7 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 	}
 
 	if k.IsNameError(err) {
-		if plugin.Fallthrough(k.Fallthrough, state.Name()) {
+		if k.Fall.Through(state.Name()) {
 			return plugin.NextOrFailure(k.Name(), k.Next, ctx, w, r)
 		}
 		return plugin.BackendError(&k, zone, dns.RcodeNameError, state, nil /* err */, plugin.Options{})

plugin/kubernetes/kubernetes.go

@@ -12,6 +12,7 @@ import (
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/plugin/etcd/msg"
 	"github.com/coredns/coredns/plugin/pkg/dnsutil"
+	"github.com/coredns/coredns/plugin/pkg/fall"
 	"github.com/coredns/coredns/plugin/pkg/healthcheck"
 	"github.com/coredns/coredns/plugin/proxy"
 	"github.com/coredns/coredns/request"
@@ -40,7 +41,7 @@ type Kubernetes struct {
 	Namespaces       map[string]bool
 	podMode          string
 	endpointNameMode bool
-	Fallthrough      *[]string // nil = disabled, empty = all zones, o/w zones
+	Fall             *fall.F
 	ttl              uint32
 
 	primaryZoneIndex   int

plugin/kubernetes/setup.go

@@ -10,6 +10,7 @@ import (
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/plugin/pkg/dnsutil"
+	"github.com/coredns/coredns/plugin/pkg/fall"
 	"github.com/coredns/coredns/plugin/proxy"
 
 	"github.com/mholt/caddy"
@@ -172,8 +173,8 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, dnsControlOpts, error) {
 				}
 				return nil, opts, c.ArgErr()
 			case "fallthrough":
-				zones := c.RemainingArgs()
-				k8s.Fallthrough = &zones
+				k8s.Fall = fall.New()
+				k8s.Fall.SetZones(c.RemainingArgs())
 			case "upstream":
 				args := c.RemainingArgs()
 				if len(args) == 0 {

plugin/kubernetes/setup_test.go

@@ -347,7 +347,7 @@ func TestKubernetesParse(t *testing.T) {
 			defaultResyncPeriod,
 			"",
 			podModeDisabled,
-			&[]string{"ip6.arpa", "inaddr.arpa", "foo.com"},
+			&[]string{"ip6.arpa.", "inaddr.arpa.", "foo.com."},
 			nil,
 		},
 		// Valid upstream
@@ -443,7 +443,7 @@ func TestKubernetesParse(t *testing.T) {
 		}
 
 		// fallthrough
-		foundFallthrough := k8sController.Fallthrough
+		foundFallthrough := k8sController.Fall
 		if foundFallthrough != nil {
 			failed := false
 			if test.expectedFallthrough == nil {