Merge pull request #10 from hashicorp/f-config-helpers

Complex configuration (non-string) works with Diff helpers

flatmap/expand.go

@@ -0,0 +1,73 @@
+package flatmap
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Expand takes a map and a key (prefix) and expands that value into
+// a more complex structure. This is the reverse of the Flatten operation.
+func Expand(m map[string]string, key string) interface{} {
+	// If the key is exactly a key in the map, just return it
+	if v, ok := m[key]; ok {
+		if num, err := strconv.ParseInt(v, 0, 0); err == nil {
+			return int(num)
+		} else if v == "true" {
+			return true
+		} else if v == "false" {
+			return false
+		}
+
+		return v
+	}
+
+	// Check if the key is an array, and if so, expand the array
+	if _, ok := m[key+".#"]; ok {
+		return expandArray(m, key)
+	}
+
+	// Check if this is a prefix in the map
+	prefix := key + "."
+	for k, _ := range m {
+		if strings.HasPrefix(k, prefix) {
+			return expandMap(m, prefix)
+		}
+	}
+
+	return nil
+}
+
+func expandArray(m map[string]string, prefix string) []interface{} {
+	num, err := strconv.ParseInt(m[prefix+".#"], 0, 0)
+	if err != nil {
+		panic(err)
+	}
+
+	result := make([]interface{}, num)
+	for i := 0; i < int(num); i++ {
+		result[i] = Expand(m, fmt.Sprintf("%s.%d", prefix, i))
+	}
+
+	return result
+}
+
+func expandMap(m map[string]string, prefix string) map[string]interface{} {
+	result := make(map[string]interface{})
+	for k, _ := range m {
+		if !strings.HasPrefix(k, prefix) {
+			continue
+		}
+
+		key := k[len(prefix):]
+		idx := strings.Index(key, ".")
+		if idx == -1 {
+			idx = len(k)
+		}
+
+		// It contains a period, so it is a more complex structure
+		result[key] = Expand(m, k[:idx])
+	}
+
+	return result
+}

flatmap/expand_test.go

@@ -0,0 +1,65 @@
+package flatmap
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestExpand(t *testing.T) {
+	cases := []struct {
+		Map    map[string]string
+		Key    string
+		Output interface{}
+	}{
+		{
+			Map: map[string]string{
+				"foo": "bar",
+				"bar": "baz",
+			},
+			Key:    "foo",
+			Output: "bar",
+		},
+
+		{
+			Map: map[string]string{
+				"foo.#": "2",
+				"foo.0": "one",
+				"foo.1": "two",
+			},
+			Key: "foo",
+			Output: []interface{}{
+				"one",
+				"two",
+			},
+		},
+
+		{
+			Map: map[string]string{
+				"foo.#":         "1",
+				"foo.0.name":    "bar",
+				"foo.0.port":    "3000",
+				"foo.0.enabled": "true",
+			},
+			Key: "foo",
+			Output: []interface{}{
+				map[string]interface{}{
+					"name":    "bar",
+					"port":    3000,
+					"enabled": true,
+				},
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		actual := Expand(tc.Map, tc.Key)
+		if !reflect.DeepEqual(actual, tc.Output) {
+			t.Fatalf(
+				"Key: %v\nMap:\n\n%#v\n\nOutput:\n\n%#v\n\nExpected:\n\n%#v\n",
+				tc.Key,
+				tc.Map,
+				actual,
+				tc.Output)
+		}
+	}
+}

flatmap/flatten.go

@@ -0,0 +1,71 @@
+package flatmap
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// Flatten takes a structure and turns into a flat map[string]string.
+//
+// Within the "thing" parameter, only primitive values are allowed. Structs are
+// not supported. Therefore, it can only be slices, maps, primitives, and
+// any combination of those together.
+//
+// See the tests for examples of what inputs are turned into.
+func Flatten(thing map[string]interface{}) map[string]string {
+	result := make(map[string]string)
+
+	for k, raw := range thing {
+		flatten(result, k, reflect.ValueOf(raw))
+	}
+
+	return result
+}
+
+func flatten(result map[string]string, prefix string, v reflect.Value) {
+	if v.Kind() == reflect.Interface {
+		v = v.Elem()
+	}
+
+	switch v.Kind() {
+	case reflect.Bool:
+		if v.Bool() {
+			result[prefix] = "true"
+		} else {
+			result[prefix] = "false"
+		}
+	case reflect.Int:
+		result[prefix] = fmt.Sprintf("%d", v.Int())
+	case reflect.Map:
+		flattenMap(result, prefix, v)
+	case reflect.Slice:
+		flattenSlice(result, prefix, v)
+	case reflect.String:
+		result[prefix] = v.String()
+	default:
+		panic(fmt.Sprintf("Unknown: %s", v))
+	}
+}
+
+func flattenMap(result map[string]string, prefix string, v reflect.Value) {
+	for _, k := range v.MapKeys() {
+		if k.Kind() == reflect.Interface {
+			k = k.Elem()
+		}
+
+		if k.Kind() != reflect.String {
+			panic(fmt.Sprintf("%s: map key is not string: %s", prefix, k))
+		}
+
+		flatten(result, fmt.Sprintf("%s.%s", prefix, k.String()), v.MapIndex(k))
+	}
+}
+
+func flattenSlice(result map[string]string, prefix string, v reflect.Value) {
+	prefix = prefix + "."
+
+	result[prefix+"#"] = fmt.Sprintf("%d", v.Len())
+	for i := 0; i < v.Len(); i++ {
+		flatten(result, fmt.Sprintf("%s%d", prefix, i), v.Index(i))
+	}
+}

flatmap/flatten_test.go

@@ -0,0 +1,67 @@
+package flatmap
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestFlatten(t *testing.T) {
+	cases := []struct {
+		Input  map[string]interface{}
+		Output map[string]string
+	}{
+		{
+			Input: map[string]interface{}{
+				"foo": "bar",
+				"bar": "baz",
+			},
+			Output: map[string]string{
+				"foo": "bar",
+				"bar": "baz",
+			},
+		},
+
+		{
+			Input: map[string]interface{}{
+				"foo": []string{
+					"one",
+					"two",
+				},
+			},
+			Output: map[string]string{
+				"foo.#": "2",
+				"foo.0": "one",
+				"foo.1": "two",
+			},
+		},
+
+		{
+			Input: map[string]interface{}{
+				"foo": []map[interface{}]interface{}{
+					map[interface{}]interface{}{
+						"name":    "bar",
+						"port":    3000,
+						"enabled": true,
+					},
+				},
+			},
+			Output: map[string]string{
+				"foo.#":         "1",
+				"foo.0.name":    "bar",
+				"foo.0.port":    "3000",
+				"foo.0.enabled": "true",
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		actual := Flatten(tc.Input)
+		if !reflect.DeepEqual(actual, tc.Output) {
+			t.Fatalf(
+				"Input:\n\n%#v\n\nOutput:\n\n%#v\n\nExpected:\n\n%#v\n",
+				tc.Input,
+				actual,
+				tc.Output)
+		}
+	}
+}

helper/diff/resource_builder.go

@@ -1,14 +1,43 @@
 package diff
 
 import (
+	"strings"
+
+	"github.com/hashicorp/terraform/flatmap"
 	"github.com/hashicorp/terraform/terraform"
 )
 
+// AttrType is an enum that tells the ResourceBuilder what type of attribute
+// an attribute is, affecting the overall diff output.
+//
+// The valid values are:
+//
+//   * AttrTypeCreate - This attribute can only be set or updated on create.
+//       This means that if this attribute is changed, it will require a new
+//       resource to be created if it is already created.
+//
+//   * AttrTypeUpdate - This attribute can be set at create time or updated
+//       in-place. Changing this attribute does not require a new resource.
+//
+type AttrType byte
+
+const (
+	AttrTypeUnknown AttrType = iota
+	AttrTypeCreate
+	AttrTypeUpdate
+)
+
 // ResourceBuilder is a helper that knows about how a single resource
 // changes and how those changes affect the diff.
 type ResourceBuilder struct {
-	CreateComputedAttrs []string
-	RequiresNewAttrs    []string
+	// Attrs are the mapping of attributes that can be set from the
+	// configuration, and the affect they have. See the documentation for
+	// AttrType for more info.
+	Attrs map[string]AttrType
+
+	// ComputedAttrs are the attributes that are computed at
+	// resource creation time.
+	ComputedAttrs []string
 }
 
 // Diff returns the ResourceDiff for a resource given its state and
@@ -18,45 +47,52 @@ func (b *ResourceBuilder) Diff(
 	c *terraform.ResourceConfig) (*terraform.ResourceDiff, error) {
 	attrs := make(map[string]*terraform.ResourceAttrDiff)
 
-	requiresNewSet := make(map[string]struct{})
-	for _, k := range b.RequiresNewAttrs {
-		requiresNewSet[k] = struct{}{}
-	}
-
 	// We require a new resource if the ID is empty. Or, later, we set
 	// this to true if any configuration changed that triggers a new resource.
 	requiresNew := s.ID == ""
 
-	// Go through the configuration and find the changed attributes
-	for k, v := range c.Raw {
-		newV := v.(string)
+	// Flatten the raw and processed configuration
+	flatRaw := flatmap.Flatten(c.Raw)
+	flatConfig := flatmap.Flatten(c.Config)
+
+	for k, v := range flatRaw {
+		// Make sure this is an attribute that actually affects
+		// the diff in some way.
+		var attr AttrType
+		for ak, at := range b.Attrs {
+			if strings.HasPrefix(k, ak) {
+				attr = at
+				break
+			}
+		}
+		if attr == AttrTypeUnknown {
+			continue
+		}
 
 		// If this key is in the cleaned config, then use that value
 		// because it'll have its variables properly interpolated
-		if cleanV, ok := c.Config[k]; ok {
-			newV = cleanV.(string)
+		if cleanV, ok := flatConfig[k]; ok {
+			v = cleanV
 		}
 
-		var oldV string
-		var ok bool
-		if oldV, ok = s.Attributes[k]; ok {
-			// Old value exists! We check to see if there is a change
-			if oldV == newV {
+		oldV, ok := s.Attributes[k]
+
+		// If there is an old value and they're the same, no change
+		if ok && oldV == v {
 			continue
 		}
-		}
 
-		// There has been a change. Record it
+		// Record the change
 		attrs[k] = &terraform.ResourceAttrDiff{
 			Old:  oldV,
-			New: newV,
+			New:  v,
+			Type: terraform.DiffAttrInput,
 		}
 
 		// If this requires a new resource, record that and flag our
 		// boolean.
-		if _, ok := requiresNewSet[k]; ok {
+		if attr == AttrTypeCreate {
 			attrs[k].RequiresNew = true
-			attrs[k].Type = terraform.DiffAttrInput
 			requiresNew = true
 		}
 	}
@@ -64,7 +100,7 @@ func (b *ResourceBuilder) Diff(
 	// If we require a new resource, then process all the attributes
 	// that will be changing due to the creation of the resource.
 	if requiresNew {
-		for _, k := range b.CreateComputedAttrs {
+		for _, k := range b.ComputedAttrs {
 			old := s.Attributes[k]
 			attrs[k] = &terraform.ResourceAttrDiff{
 				Old:         old,

helper/diff/resource_builder_test.go

@@ -7,9 +7,51 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
+func TestResourceBuilder_complex(t *testing.T) {
+	rb := &ResourceBuilder{
+		Attrs: map[string]AttrType{
+			"listener": AttrTypeUpdate,
+		},
+	}
+
+	state := &terraform.ResourceState{
+		ID: "foo",
+		Attributes: map[string]string{
+			"ignore":          "1",
+			"listener.#":      "1",
+			"listener.0.port": "80",
+		},
+	}
+
+	c := testConfig(t, map[string]interface{}{
+		"listener": []interface{}{
+			map[interface{}]interface{}{
+				"port": 3000,
+			},
+		},
+	}, nil)
+
+	diff, err := rb.Diff(state, c)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if diff == nil {
+		t.Fatal("should not be nil")
+	}
+
+	actual := testResourceDiffStr(diff)
+	expected := testRBComplexDiff
+	if actual != expected {
+		t.Fatalf("bad: %s", actual)
+	}
+}
+
 func TestResourceBuilder_new(t *testing.T) {
 	rb := &ResourceBuilder{
-		CreateComputedAttrs: []string{"private_ip"},
+		Attrs: map[string]AttrType{
+			"foo": AttrTypeUpdate,
+		},
+		ComputedAttrs: []string{"private_ip"},
 	}
 
 	state := &terraform.ResourceState{}
@@ -35,8 +77,10 @@ func TestResourceBuilder_new(t *testing.T) {
 
 func TestResourceBuilder_requiresNew(t *testing.T) {
 	rb := &ResourceBuilder{
-		CreateComputedAttrs: []string{"private_ip"},
-		RequiresNewAttrs:    []string{"ami"},
+		ComputedAttrs: []string{"private_ip"},
+		Attrs: map[string]AttrType{
+			"ami": AttrTypeCreate,
+		},
 	}
 
 	state := &terraform.ResourceState{
@@ -68,7 +112,7 @@ func TestResourceBuilder_requiresNew(t *testing.T) {
 
 func TestResourceBuilder_same(t *testing.T) {
 	rb := &ResourceBuilder{
-		CreateComputedAttrs: []string{"private_ip"},
+		ComputedAttrs: []string{"private_ip"},
 	}
 
 	state := &terraform.ResourceState{
@@ -92,7 +136,11 @@ func TestResourceBuilder_same(t *testing.T) {
 }
 
 func TestResourceBuilder_unknown(t *testing.T) {
-	rb := &ResourceBuilder{}
+	rb := &ResourceBuilder{
+		Attrs: map[string]AttrType{
+			"foo": AttrTypeUpdate,
+		},
+	}
 
 	state := &terraform.ResourceState{}
 
@@ -119,7 +167,11 @@ func TestResourceBuilder_unknown(t *testing.T) {
 }
 
 func TestResourceBuilder_vars(t *testing.T) {
-	rb := &ResourceBuilder{}
+	rb := &ResourceBuilder{
+		Attrs: map[string]AttrType{
+			"foo": AttrTypeUpdate,
+		},
+	}
 
 	state := &terraform.ResourceState{}
 
@@ -144,6 +196,10 @@ func TestResourceBuilder_vars(t *testing.T) {
 	}
 }
 
+const testRBComplexDiff = `UPDATE
+  IN  listener.0.port: "80" => "3000"
+`
+
 const testRBNewDiff = `UPDATE
   IN  foo:        "" => "bar"
   OUT private_ip: "" => "<computed>"