mw/kubernetes: remove subzones (#878)

Only use was in k8s middleware; no tests other than subzone_test.go
existed; not exercised: remove.

middleware/kubernetes/setup.go

@@ -68,14 +68,16 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
 		if c.Val() == "kubernetes" {
 			zones := c.RemainingArgs()
 
-			if len(zones) == 0 {
+			if len(zones) != 0 {
+				k8s.Zones = zones
+				middleware.Zones(k8s.Zones).Normalize()
+			} else {
 				k8s.Zones = make([]string, len(c.ServerBlockKeys))
-				copy(k8s.Zones, c.ServerBlockKeys)
+				for i := 0; i < len(c.ServerBlockKeys); i++ {
+					k8s.Zones[i] = middleware.Host(c.ServerBlockKeys[i]).Normalize()
+				}
 			}
 
-			k8s.Zones = NormalizeZoneList(zones)
-			middleware.Zones(k8s.Zones).Normalize()
-
 			if k8s.Zones == nil || len(k8s.Zones) < 1 {
 				return nil, errors.New("zone name must be provided for kubernetes middleware")
 			}

middleware/kubernetes/subzone.go

-package kubernetes
-
-import (
-	"log"
-
-	"github.com/miekg/dns"
-)
-
-// NormalizeZoneList filters the zones argument to remove
-// array items that conflict with other items in zones.
-// For example, providing the following zones array:
-//    [ "a.b.c", "b.c", "a", "e.d.f", "a.b" ]
-// Returns:
-//    [ "a.b.c", "a", "e.d.f", "a.b" ]
-// Zones filted out:
-//    - "b.c" because "a.b.c" and "b.c" share the common top
-//      level "b.c". First listed zone wins if there is a conflict.
-//
-// Note: This may prove to be too restrictive in practice.
-//       Need to find counter-example use-cases.
-func NormalizeZoneList(zones []string) []string {
-	filteredZones := []string{}
-
-	for _, z := range zones {
-		zoneConflict, _ := subzoneConflict(filteredZones, z)
-		if zoneConflict {
-			log.Printf("[WARN] new zone '%v' from Corefile conflicts with existing zones: %v\n        Ignoring zone '%v'\n", z, filteredZones, z)
-		} else {
-			filteredZones = append(filteredZones, z)
-		}
-	}
-
-	return filteredZones
-}
-
-// subzoneConflict returns true if name is a child or parent zone of
-// any element in zones. If conflicts exist, return the conflicting zones.
-func subzoneConflict(zones []string, name string) (bool, []string) {
-	conflicts := []string{}
-
-	for _, z := range zones {
-		if dns.IsSubDomain(z, name) || dns.IsSubDomain(name, z) {
-			conflicts = append(conflicts, z)
-		}
-	}
-
-	return (len(conflicts) != 0), conflicts
-}

middleware/kubernetes/subzone_test.go

-package kubernetes
-
-import (
-	"testing"
-)
-
-// List of configured zones to test against
-var confZones = []string{
-	"a.b.c",
-	"d",
-}
-
-// Map of zonename :: expected boolean result
-var examplesSubzoneConflict = map[string]bool{
-	"a.b.c":   true,  // conflicts with zone "a.b.c"
-	"b.c":     true,  // conflicts with zone "a.b.c"
-	"c":       true,  // conflicts with zone "a.b.c"
-	"e":       false, // no conflict
-	"a.b.c.e": false, // no conflict
-	"a.b.c.d": true,  // conflicts with zone "d"
-	"":        false,
-}
-
-func TestSubzoneConflict(t *testing.T) {
-	for z, expected := range examplesSubzoneConflict {
-		actual, conflicts := subzoneConflict(confZones, z)
-
-		if actual != expected {
-			t.Errorf("Expected conflict result '%v' for example '%v'. Instead got '%v'. Conflicting zones are: %v", expected, z, actual, conflicts)
-		}
-	}
-}