builder/amazonebs: Artifact ID works

builder/amazonebs/artifact.go

@@ -25,9 +25,13 @@ func (*artifact) Files() []string {
 	return nil
 }
 
-func (*artifact) Id() string {
-	// TODO(mitchellh): Id
-	return "TODO"
+func (a *artifact) Id() string {
+	parts := make([]string, 0, len(a.amis))
+	for region, amiId := range a.amis {
+		parts = append(parts, fmt.Sprintf("%s:%s", region, amiId))
+	}
+
+	return strings.Join(parts, ",")
 }
 
 func (a *artifact) String() string {

builder/amazonebs/artifact_test.go

@@ -13,6 +13,20 @@ func TestArtifact_Impl(t *testing.T) {
 	assert.Implementor(&artifact{}, &actual, "should be an Artifact")
 }
 
+func TestArtifactId(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	expected := `east:foo,west:bar`
+
+	amis := make(map[string]string)
+	amis["east"] = "foo"
+	amis["west"] = "bar"
+
+	a := &artifact{amis, nil}
+	result := a.Id()
+	assert.Equal(result, expected, "should match output")
+}
+
 func TestArtifactString(t *testing.T) {
 	assert := asserts.NewTestingAsserts(t, true)