interpolate: Expand computed TypeList attributes properly

terraform/interpolate.go

@@ -2,7 +2,10 @@ package terraform
 
 import (
 	"fmt"
+	"log"
 	"os"
+	"regexp"
+	"sort"
 	"strings"
 	"sync"
 
@@ -327,6 +330,11 @@ func (i *Interpolater) computeResourceVariable(
 		return attr, nil
 	}
 
+	// computed list attribute
+	if _, ok := r.Primary.Attributes[v.Field+".#"]; ok {
+		return i.interpolateListAttribute(v.Field, r.Primary.Attributes)
+	}
+
 	// At apply time, we can't do the "maybe has it" check below
 	// that we need for plans since parent elements might be computed.
 	// Therefore, it is an error and we're missing the key.
@@ -410,8 +418,8 @@ func (i *Interpolater) computeResourceMultiVariable(
 	}
 
 	var values []string
-	for i := 0; i < count; i++ {
+	for j := 0; j < count; j++ {
-		id := fmt.Sprintf("%s.%d", v.ResourceId(), i)
+		id := fmt.Sprintf("%s.%d", v.ResourceId(), j)
 
 		// If we're dealing with only a single resource, then the
 		// ID doesn't have a trailing index.
@@ -430,6 +438,21 @@ func (i *Interpolater) computeResourceMultiVariable(
 
 		attr, ok := r.Primary.Attributes[v.Field]
 		if !ok {
+			// computed list attribute
+			_, ok := r.Primary.Attributes[v.Field+".#"]
+			if !ok {
+				continue
+			}
+			attr, err = i.interpolateListAttribute(v.Field, r.Primary.Attributes)
+			if err != nil {
+				return "", err
+			}
+		}
+
+		if config.IsStringList(attr) {
+			for _, s := range config.StringList(attr).Slice() {
+				values = append(values, s)
+			}
 			continue
 		}
 
@@ -461,6 +484,26 @@ func (i *Interpolater) computeResourceMultiVariable(
 	return config.NewStringList(values).String(), nil
 }
 
+func (i *Interpolater) interpolateListAttribute(
+	resourceID string,
+	attributes map[string]string) (string, error) {
+
+	attr := attributes[resourceID+".#"]
+	log.Printf("[DEBUG] Interpolating computed list attribute %s (%s)",
+		resourceID, attr)
+
+	var members []string
+	numberedListMember := regexp.MustCompile("^" + resourceID + "\\.[0-9]+$")
+	for id, value := range attributes {
+		if numberedListMember.MatchString(id) {
+			members = append(members, value)
+		}
+	}
+
+	sort.Strings(members)
+	return config.NewStringList(members).String(), nil
+}
+
 func (i *Interpolater) resourceVariableInfo(
 	scope *InterpolationScope,
 	v *config.ResourceVariable) (*ModuleState, *config.Resource, error) {

terraform/interpolate_test.go

@@ -210,6 +210,208 @@ func TestInterpolater_resourceVariableMulti(t *testing.T) {
 	})
 }
 
+func TestInterpolator_resourceMultiAttributes(t *testing.T) {
+	lock := new(sync.RWMutex)
+	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: "AAABBBCCCDDDEEE",
+							Attributes: map[string]string{
+								"name_servers.#": "4",
+								"name_servers.0": "ns-1334.awsdns-38.org",
+								"name_servers.1": "ns-1680.awsdns-18.co.uk",
+								"name_servers.2": "ns-498.awsdns-62.com",
+								"name_servers.3": "ns-601.awsdns-11.net",
+								"listeners.#":    "1",
+								"listeners.0":    "red",
+								"tags.#":         "1",
+								"tags.Name":      "reindeer",
+								"nothing.#":      "0",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	i := &Interpolater{
+		Module:    testModule(t, "interpolate-multi-vars"),
+		StateLock: lock,
+		State:     state,
+	}
+
+	scope := &InterpolationScope{
+		Path: rootModulePath,
+	}
+
+	name_servers := []string{
+		"ns-1334.awsdns-38.org",
+		"ns-1680.awsdns-18.co.uk",
+		"ns-498.awsdns-62.com",
+		"ns-601.awsdns-11.net",
+	}
+	expectedNameServers := config.NewStringList(name_servers).String()
+
+	// More than 1 element
+	testInterpolate(t, i, scope, "aws_route53_zone.yada.name_servers", ast.Variable{
+		Value: expectedNameServers,
+		Type:  ast.TypeString,
+	})
+
+	// Exactly 1 element
+	testInterpolate(t, i, scope, "aws_route53_zone.yada.listeners", ast.Variable{
+		Value: config.NewStringList([]string{"red"}).String(),
+		Type:  ast.TypeString,
+	})
+
+	// Zero elements
+	testInterpolate(t, i, scope, "aws_route53_zone.yada.nothing", ast.Variable{
+		Value: config.NewStringList([]string{}).String(),
+		Type:  ast.TypeString,
+	})
+
+	// Maps still need to work
+	testInterpolate(t, i, scope, "aws_route53_zone.yada.tags.Name", ast.Variable{
+		Value: "reindeer",
+		Type:  ast.TypeString,
+	})
+}
+
+func TestInterpolator_resourceMultiAttributesWithResourceCount(t *testing.T) {
+	i := getInterpolaterFixture(t)
+	scope := &InterpolationScope{
+		Path: rootModulePath,
+	}
+
+	name_servers := []string{
+		"ns-1334.awsdns-38.org",
+		"ns-1680.awsdns-18.co.uk",
+		"ns-498.awsdns-62.com",
+		"ns-601.awsdns-11.net",
+		"ns-000.awsdns-38.org",
+		"ns-444.awsdns-18.co.uk",
+		"ns-666.awsdns-11.net",
+		"ns-999.awsdns-62.com",
+	}
+
+	// More than 1 element
+	expectedNameServers := config.NewStringList(name_servers[0:4]).String()
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.0.name_servers", ast.Variable{
+		Value: expectedNameServers,
+		Type:  ast.TypeString,
+	})
+	// More than 1 element in both
+	expectedNameServers = config.NewStringList(name_servers).String()
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.*.name_servers", ast.Variable{
+		Value: expectedNameServers,
+		Type:  ast.TypeString,
+	})
+
+	// Exactly 1 element
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.0.listeners", ast.Variable{
+		Value: config.NewStringList([]string{"red"}).String(),
+		Type:  ast.TypeString,
+	})
+	// Exactly 1 element in both
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.*.listeners", ast.Variable{
+		Value: config.NewStringList([]string{"red", "blue"}).String(),
+		Type:  ast.TypeString,
+	})
+
+	// Zero elements
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.0.nothing", ast.Variable{
+		Value: config.NewStringList([]string{}).String(),
+		Type:  ast.TypeString,
+	})
+	// Zero + zero elements
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.*.nothing", ast.Variable{
+		Value: config.NewStringList([]string{"", ""}).String(),
+		Type:  ast.TypeString,
+	})
+	// Zero + 1 element
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.*.special", ast.Variable{
+		Value: config.NewStringList([]string{"extra"}).String(),
+		Type:  ast.TypeString,
+	})
+
+	// Maps still need to work
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.0.tags.Name", ast.Variable{
+		Value: "reindeer",
+		Type:  ast.TypeString,
+	})
+	// Maps still need to work in both
+	testInterpolate(t, i, scope, "aws_route53_zone.terra.*.tags.Name", ast.Variable{
+		Value: config.NewStringList([]string{"reindeer", "white-hart"}).String(),
+		Type:  ast.TypeString,
+	})
+}
+
+func getInterpolaterFixture(t *testing.T) *Interpolater {
+	lock := new(sync.RWMutex)
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_route53_zone.terra.0": &ResourceState{
+						Type:         "aws_route53_zone",
+						Dependencies: []string{},
+						Primary: &InstanceState{
+							ID: "AAABBBCCCDDDEEE",
+							Attributes: map[string]string{
+								"name_servers.#": "4",
+								"name_servers.0": "ns-1334.awsdns-38.org",
+								"name_servers.1": "ns-1680.awsdns-18.co.uk",
+								"name_servers.2": "ns-498.awsdns-62.com",
+								"name_servers.3": "ns-601.awsdns-11.net",
+								"listeners.#":    "1",
+								"listeners.0":    "red",
+								"tags.#":         "1",
+								"tags.Name":      "reindeer",
+								"nothing.#":      "0",
+							},
+						},
+					},
+					"aws_route53_zone.terra.1": &ResourceState{
+						Type:         "aws_route53_zone",
+						Dependencies: []string{},
+						Primary: &InstanceState{
+							ID: "EEEFFFGGGHHHIII",
+							Attributes: map[string]string{
+								"name_servers.#": "4",
+								"name_servers.0": "ns-000.awsdns-38.org",
+								"name_servers.1": "ns-444.awsdns-18.co.uk",
+								"name_servers.2": "ns-999.awsdns-62.com",
+								"name_servers.3": "ns-666.awsdns-11.net",
+								"listeners.#":    "1",
+								"listeners.0":    "blue",
+								"special.#":      "1",
+								"special.0":      "extra",
+								"tags.#":         "1",
+								"tags.Name":      "white-hart",
+								"nothing.#":      "0",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	return &Interpolater{
+		Module:    testModule(t, "interpolate-multi-vars"),
+		StateLock: lock,
+		State:     state,
+	}
+}
+
 func testInterpolate(
 	t *testing.T, i *Interpolater,
 	scope *InterpolationScope,
@@ -230,6 +432,6 @@ func testInterpolate(
 		"foo": expectedVar,
 	}
 	if !reflect.DeepEqual(actual, expected) {
-		t.Fatalf("bad: %#v", actual)
+		t.Fatalf("%q: actual: %#v\nexpected: %#v", n, actual, expected)
 	}
 }

terraform/test-fixtures/interpolate-multi-vars/main.tf

@@ -0,0 +1,7 @@
+resource "aws_route53_zone" "yada" {
+
+}
+
+resource "aws_route53_zone" "terra" {
+	count = 2
+}