Use flatmap.Expand to extract interpolated values

Now that flatmap.Expand will properly expand nested maps, we can use
that to extract any lists and maps when interpolating.

terraform/interpolate.go

@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"regexp"
-	"sort"
 	"strconv"
 	"strings"
 	"sync"
@@ -620,33 +618,6 @@ func (i *Interpolater) computeResourceMultiVariable(
 	return &variable, err
 }
 
-type indexKeys []string
-
-// we need to separate the index integer from the ID, and sort numerically
-func (i indexKeys) Less(j, k int) bool {
-	jDot := strings.LastIndex(i[j], ".")
-	kDot := strings.LastIndex(i[j], ".")
-
-	// These should all be properly formatted, but check the indexes and return
-	// a safe value just in case.
-	if jDot < 0 || kDot < 0 {
-		return i[j] < i[k]
-	}
-
-	jIdx, _ := strconv.Atoi(i[j][jDot+1:])
-	kIdx, _ := strconv.Atoi(i[k][kDot+1:])
-
-	return jIdx < kIdx
-}
-
-func (i indexKeys) Swap(j, k int) {
-	i[j], i[k] = i[k], i[j]
-}
-
-func (i indexKeys) Len() int {
-	return len(i)
-}
-
 func (i *Interpolater) interpolateComplexTypeAttribute(
 	resourceID string,
 	attributes map[string]string) (ast.Variable, error) {
@@ -668,23 +639,8 @@ func (i *Interpolater) interpolateComplexTypeAttribute(
 			return unknownVariable(), nil
 		}
 
-		keys := make([]string, 0)
-		listElementKey := regexp.MustCompile("^" + resourceID + "\\.[0-9]+$")
-		for id := range attributes {
-			if listElementKey.MatchString(id) {
-				keys = append(keys, id)
-			}
-		}
-
-		// sort the keys by their index number, rather than lexicographically by the key
-		sort.Sort(indexKeys(keys))
-
-		var members []string
-		for _, key := range keys {
-			members = append(members, attributes[key])
-		}
-
-		return hil.InterfaceToVariable(members)
+		expanded := flatmap.Expand(attributes, resourceID)
+		return hil.InterfaceToVariable(expanded)
 	}
 
 	if lengthAttr, isMap := attributes[resourceID+".%"]; isMap {
@@ -699,15 +655,7 @@ func (i *Interpolater) interpolateComplexTypeAttribute(
 			return unknownVariable(), nil
 		}
 
-		resourceFlatMap := make(map[string]string)
-		mapElementKey := regexp.MustCompile("^" + resourceID + "\\.([^%]+)$")
-		for id, val := range attributes {
-			if mapElementKey.MatchString(id) {
-				resourceFlatMap[id] = val
-			}
-		}
-
-		expanded := flatmap.Expand(resourceFlatMap, resourceID)
+		expanded := flatmap.Expand(attributes, resourceID)
 		return hil.InterfaceToVariable(expanded)
 	}
 

terraform/interpolate_test.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"os"
 	"reflect"
-	"sort"
 	"sync"
 	"testing"
 
@@ -675,19 +674,6 @@ func TestInterpolater_selfVarWithoutResource(t *testing.T) {
 	}
 }
 
-// Verify sorting by key index number
-func TestInterpolator_indexKeySort(t *testing.T) {
-	keys := []string{"a.1", "a.2", "a.10", "a.20", "a.3"}
-	sorted := []string{"a.1", "a.2", "a.3", "a.10", "a.20"}
-
-	sort.Sort(indexKeys(keys))
-	for i := range keys {
-		if keys[i] != sorted[i] {
-			t.Fatalf("indexes out of order\nexpected: %q\ngot: %q", sorted, keys)
-		}
-	}
-}
-
 func TestInterpolator_interpolatedListOrder(t *testing.T) {
 	state := &State{
 		Modules: []*ModuleState{
@@ -796,6 +782,62 @@ func getInterpolaterFixture(t *testing.T) *Interpolater {
 	}
 }
 
+func TestInterpolator_nestedMapsAndLists(t *testing.T) {
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_route53_zone.yada": &ResourceState{
+						Type:         "aws_route53_zone",
+						Dependencies: []string{},
+						Primary: &InstanceState{
+							ID: "null",
+							Attributes: map[string]string{
+								"list_of_map.#":       "2",
+								"list_of_map.0.%":     "1",
+								"list_of_map.0.a":     "1",
+								"list_of_map.1.%":     "1",
+								"list_of_map.1.b":     "2",
+								"map_of_list.%":       "2",
+								"map_of_list.list2.#": "1",
+								"map_of_list.list2.0": "b",
+								"map_of_list.list1.#": "1",
+								"map_of_list.list1.0": "a",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	i := &Interpolater{
+		Module:    testModule(t, "interpolate-multi-vars"),
+		StateLock: new(sync.RWMutex),
+		State:     state,
+	}
+
+	scope := &InterpolationScope{
+		Path: rootModulePath,
+	}
+
+	listOfMap := []interface{}{
+		map[string]interface{}{"a": "1"},
+		map[string]interface{}{"b": "2"},
+	}
+
+	mapOfList := map[string]interface{}{
+		"list1": []interface{}{"a"},
+		"list2": []interface{}{"b"},
+	}
+
+	testInterpolate(t, i, scope, "aws_route53_zone.yada.list_of_map",
+		interfaceToVariableSwallowError(listOfMap))
+	testInterpolate(t, i, scope, `aws_route53_zone.yada.map_of_list`,
+		interfaceToVariableSwallowError(mapOfList))
+}
+
 func testInterpolate(
 	t *testing.T, i *Interpolater,
 	scope *InterpolationScope,