diff --git a/config/config_test.go b/config/config_test.go
index 0937e3cb..d382249e 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -10,55 +10,6 @@ import (
 	"strings"
 )
 
-func TestNilMap(t *testing.T) {
-	assert := require.New(t)
-	var m map[string]interface{} = nil
-	assert.True(m == nil)
-}
-
-func TestMapCopy(t *testing.T) {
-	assert := require.New(t)
-	m0 := map[interface{}]interface{}{"a": 1, "b": map[interface{}]interface{}{"c": 3}, "d": "4"}
-	m1 := util.MapCopy(m0)
-
-	delete(m0, "a")
-	assert.Equal(len(m1), len(m0)+1)
-
-	b0 := m0["b"].(map[interface{}]interface{})
-	b1 := m1["b"].(map[interface{}]interface{})
-	b1["e"] = "queer"
-
-	assert.Equal(len(b1), len(b0)+1)
-}
-
-func TestMapsIntersection(t *testing.T) {
-	assert := require.New(t)
-
-	m0 := map[interface{}]interface{}{"a": 1, "b": map[interface{}]interface{}{"c": 3}, "d": "4"}
-	m1 := util.MapCopy(m0)
-
-	delete(m0, "a")
-	b1 := m1["b"].(map[interface{}]interface{})
-	delete(b1, "c")
-	expected := map[interface{}]interface{}{"b": map[interface{}]interface{}{}, "d": "4"}
-	assert.Equal(expected, util.MapsIntersection(m0, m1, util.Equal))
-}
-
-func TestMapsUnion(t *testing.T) {
-	assert := require.New(t)
-
-	m0 := map[interface{}]interface{}{"a": 1, "b": map[interface{}]interface{}{"c": 3}, "d": "4"}
-	m1 := util.MapCopy(m0)
-	m1["e"] = "added"
-	m1["d"] = "replaced"
-
-	delete(m0, "a")
-	b1 := m1["b"].(map[interface{}]interface{})
-	delete(b1, "c")
-	expected := map[interface{}]interface{}{"a": 1, "b": map[interface{}]interface{}{"c": 3}, "d": "replaced", "e": "added"}
-	assert.Equal(expected, util.MapsUnion(m0, m1, util.Replace))
-}
-
 func TestFilterKey(t *testing.T) {
 	assert := require.New(t)
 	data := map[interface{}]interface{}{
diff --git a/util/util.go b/util/util.go
index 6eb8e7d8..7b484c85 100644
--- a/util/util.go
+++ b/util/util.go
@@ -181,6 +181,8 @@ func Copy(d interface{}) interface{} {
 	switch d := d.(type) {
 	case map[interface{}]interface{}:
 		return MapCopy(d)
+	case []interface{}:
+		return SliceCopy(d)
 	default:
 		return d
 	}
@@ -197,11 +199,40 @@ func Equal(l, r interface{}) interface{} {
 	return nil
 }
 
+func ExistsIn(x interface{}, s []interface{}) bool {
+	for _, y := range s {
+		if reflect.DeepEqual(x, y) {
+			return true
+		}
+	}
+	return false
+}
+
+func SlicesUnion(left, right []interface{}, op func(interface{}, interface{}) interface{}) []interface{} {
+	result := SliceCopy(left)
+	for _, r := range right {
+		if !ExistsIn(r, result) {
+			result = append(result, r)
+		}
+	}
+	return result
+}
+
+func SlicesIntersection(left, right []interface{}, op func(interface{}, interface{}) interface{}) []interface{} {
+	result := []interface{}{}
+	for _, r := range right {
+		if ExistsIn(r, left) {
+			result = append(result, r)
+		}
+	}
+	return result
+}
+
 func MapsUnion(left, right map[interface{}]interface{}, op func(interface{}, interface{}) interface{}) map[interface{}]interface{} {
 	result := MapCopy(left)
 
 	for k, r := range right {
-		if l, ok := result[k]; ok {
+		if l, ok := left[k]; ok {
 			switch l := l.(type) {
 			case map[interface{}]interface{}:
 				switch r := r.(type) {
@@ -210,6 +241,13 @@ func MapsUnion(left, right map[interface{}]interface{}, op func(interface{}, int
 				default:
 					result[k] = op(l, r)
 				}
+			case []interface{}:
+				switch r := r.(type) {
+				case []interface{}:
+					result[k] = SlicesUnion(l, r, op)
+				default:
+					result[k] = op(l, r)
+				}
 			default:
 				result[k] = op(l, r)
 			}
@@ -226,19 +264,28 @@ func MapsIntersection(left, right map[interface{}]interface{}, op func(interface
 
 	for k, l := range left {
 		if r, ok := right[k]; ok {
-			switch r := r.(type) {
+			switch l := l.(type) {
 			case map[interface{}]interface{}:
-				switch l := l.(type) {
+				switch r := r.(type) {
 				case map[interface{}]interface{}:
 					result[k] = MapsIntersection(l, r, op)
 				default:
-					if i := op(l, r); i != nil {
-						result[k] = i
+					if v := op(l, r); v != nil {
+						result[k] = v
+					}
+				}
+			case []interface{}:
+				switch r := r.(type) {
+				case []interface{}:
+					result[k] = SlicesIntersection(l, r, op)
+				default:
+					if v := op(l, r); v != nil {
+						result[k] = v
 					}
 				}
 			default:
-				if i := op(l, r); i != nil {
-					result[k] = i
+				if v := op(l, r); v != nil {
+					result[k] = v
 				}
 			}
 		}
@@ -255,6 +302,14 @@ func MapCopy(data map[interface{}]interface{}) map[interface{}]interface{} {
 	return result
 }
 
+func SliceCopy(data []interface{}) []interface{} {
+	result := make([]interface{}, len(data), len(data))
+	for k, v := range data {
+		result[k] = Copy(v)
+	}
+	return result
+}
+
 func GetServices(urls []string) ([]string, error) {
 	result := []string{}
 
diff --git a/util/util_test.go b/util/util_test.go
index a2a06fdc..000ab0ec 100644
--- a/util/util_test.go
+++ b/util/util_test.go
@@ -6,6 +6,90 @@ import (
 	"testing"
 )
 
+func TestNilMap(t *testing.T) {
+	assert := require.New(t)
+	var m map[string]interface{} = nil
+	assert.True(m == nil)
+}
+
+func TestMapCopy(t *testing.T) {
+	assert := require.New(t)
+	m0 := map[interface{}]interface{}{"a": 1, "b": map[interface{}]interface{}{"c": 3}, "d": "4"}
+	m1 := MapCopy(m0)
+	assert.Equal(m0, m1)
+
+	delete(m0, "a")
+	assert.Equal(len(m1), len(m0)+1)
+
+	b0 := m0["b"].(map[interface{}]interface{})
+	b1 := m1["b"].(map[interface{}]interface{})
+	b1["e"] = "queer"
+
+	assert.Equal(len(b1), len(b0)+1)
+}
+
+func TestSliceCopy(t *testing.T) {
+	assert := require.New(t)
+	m0 := []interface{}{1, map[interface{}]interface{}{"c": 3}, "4"}
+	m1 := SliceCopy(m0)
+	assert.Equal(m0, m1)
+
+	m0 = m0[1:]
+	assert.Equal(len(m1), len(m0)+1)
+
+	b0 := m0[0].(map[interface{}]interface{})
+	b1 := m1[1].(map[interface{}]interface{})
+	b1["e"] = "queer"
+
+	assert.Equal(len(b1), len(b0)+1)
+}
+
+func TestMapsIntersection(t *testing.T) {
+	assert := require.New(t)
+
+	m0 := map[interface{}]interface{}{
+		"a": 1,
+		"b": map[interface{}]interface{}{"c": 3},
+		"d": "4",
+		"e": []interface{}{1, 2, 3},
+	}
+	m1 := MapCopy(m0)
+
+	delete(m0, "a")
+	b1 := m1["b"].(map[interface{}]interface{})
+	delete(b1, "c")
+	m1["e"] = []interface{}{2, 3, 4}
+	expected := map[interface{}]interface{}{"b": map[interface{}]interface{}{}, "d": "4", "e": []interface{}{2, 3}}
+	assert.Equal(expected, MapsIntersection(m0, m1, Equal))
+}
+
+func TestMapsUnion(t *testing.T) {
+	assert := require.New(t)
+
+	m0 := map[interface{}]interface{}{
+		"a": 1,
+		"b": map[interface{}]interface{}{"c": 3},
+		"d": "4",
+		"f": []interface{}{1, 2, 3},
+	}
+	m1 := MapCopy(m0)
+	m1["e"] = "added"
+	m1["d"] = "replaced"
+	m1["f"] = []interface{}{2, 3, 4}
+
+	delete(m0, "a")
+	b1 := m1["b"].(map[interface{}]interface{})
+	delete(b1, "c")
+	expected := map[interface{}]interface{}{
+		"a": 1,
+		"b": map[interface{}]interface{}{"c": 3},
+		"d": "replaced",
+		"e": "added",
+		"f": []interface{}{1, 2, 3, 4},
+	}
+	assert.Equal(expected, MapsUnion(m0, m1, Replace))
+}
+
 func TestLoadResourceSimple(t *testing.T) {
 	assert := require.New(t)