Don't try and create default namespace (hashicorp#396)

namespaces/namespaces.go

@@ -8,13 +8,16 @@ import (
 	capi "github.com/hashicorp/consul/api"
 )
 
-const WildcardNamespace string = "*"
+const (
+	WildcardNamespace = "*"
+	DefaultNamespace  = "default"
+)
 
 // EnsureExists ensures a Consul namespace with name ns exists. If it doesn't,
 // it will create it and set crossNSACLPolicy as a policy default.
 // Boolean return value indicates if the namespace was created by this call.
 func EnsureExists(client *capi.Client, ns string, crossNSAClPolicy string) (bool, error) {
-	if ns == WildcardNamespace {
+	if ns == WildcardNamespace || ns == DefaultNamespace {
 		return false, nil
 	}
 	// Check if the Consul namespace exists.

namespaces/namespaces_test.go

@@ -76,6 +76,13 @@ func TestEnsureExists_WildcardNamespace_AlreadyExists(tt *testing.T) {
 	require.False(tt, created)
 }
 
+// Test that if the default namespace is passed in the function succeeds.
+func TestEnsureExists_DefaultNamespace(tt *testing.T) {
+	created, err := EnsureExists(nil, DefaultNamespace, "")
+	require.NoError(tt, err)
+	require.False(tt, created)
+}
+
 // Test that it creates the namespace if it doesn't exist.
 func TestEnsureExists_CreatesNS(tt *testing.T) {
 	for _, c := range []struct {