terraform: ConfigTransformer has Unique and mode filters

terraform/test-fixtures/transform-config-mode-data/main.tf

@@ -0,0 +1,3 @@
+data "aws_ami" "foo" {}
+
+resource "aws_instance" "web" {}

terraform/transform_config.go

@@ -4,7 +4,9 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"sync"
 
+	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/config/module"
 	"github.com/hashicorp/terraform/dag"
 )
@@ -23,10 +25,25 @@ import (
 type ConfigTransformer struct {
 	Concrete ConcreteResourceNodeFunc
 
+	// Module is the module to add resources from.
 	Module *module.Tree
+
+	// Unique will only add resources that aren't already present in the graph.
+	Unique bool
+
+	// Mode will only add resources that match the given mode
+	ModeFilter bool
+	Mode       config.ResourceMode
+
+	l         sync.Mutex
+	uniqueMap map[string]struct{}
 }
 
 func (t *ConfigTransformer) Transform(g *Graph) error {
+	// Lock since we use some internal state
+	t.l.Lock()
+	defer t.l.Unlock()
+
 	// If no module is given, we don't do anything
 	if t.Module == nil {
 		return nil
@@ -37,6 +54,18 @@ func (t *ConfigTransformer) Transform(g *Graph) error {
 		return errors.New("module must be loaded for ConfigTransformer")
 	}
 
+	// Reset the uniqueness map. If we're tracking uniques, then populate
+	// it with addresses.
+	t.uniqueMap = make(map[string]struct{})
+	defer func() { t.uniqueMap = nil }()
+	if t.Unique {
+		for _, v := range g.Vertices() {
+			if rn, ok := v.(GraphNodeResource); ok {
+				t.uniqueMap[rn.ResourceAddr().String()] = struct{}{}
+			}
+		}
+	}
+
 	// Start the transformation process
 	return t.transform(g, t.Module)
 }
@@ -66,13 +95,13 @@ func (t *ConfigTransformer) transformSingle(g *Graph, m *module.Tree) error {
 	log.Printf("[TRACE] ConfigTransformer: Starting for path: %v", m.Path())
 
 	// Get the configuration for this module
-	config := m.Config()
+	conf := m.Config()
 
 	// Build the path we're at
 	path := m.Path()
 
 	// Write all the resources out
-	for _, r := range config.Resources {
+	for _, r := range conf.Resources {
 		// Build the resource address
 		addr, err := parseResourceAddressConfig(r)
 		if err != nil {
@@ -81,6 +110,16 @@ func (t *ConfigTransformer) transformSingle(g *Graph, m *module.Tree) error {
 		}
 		addr.Path = path
 
+		// If this is already in our uniqueness map, don't add it again
+		if _, ok := t.uniqueMap[addr.String()]; ok {
+			continue
+		}
+
+		// Remove non-matching modes
+		if t.ModeFilter && addr.Mode != t.Mode {
+			continue
+		}
+
 		// Build the abstract node and the concrete one
 		abstract := &NodeAbstractResource{Addr: addr}
 		var node dag.Vertex = abstract

terraform/transform_config_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/config/module"
 )
 
@@ -48,6 +49,80 @@ func TestConfigTransformer(t *testing.T) {
 	}
 }
 
+func TestConfigTransformer_mode(t *testing.T) {
+	g := Graph{Path: RootModulePath}
+	tf := &ConfigTransformer{
+		Module:     testModule(t, "transform-config-mode-data"),
+		ModeFilter: true,
+		Mode:       config.DataResourceMode,
+	}
+	if err := tf.Transform(&g); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(`
+data.aws_ami.foo
+`)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+func TestConfigTransformer_nonUnique(t *testing.T) {
+	addr, err := ParseResourceAddress("aws_instance.web")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	g := Graph{Path: RootModulePath}
+	g.Add(&NodeAbstractResource{Addr: addr})
+	tf := &ConfigTransformer{Module: testModule(t, "graph-basic")}
+	if err := tf.Transform(&g); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(`
+aws_instance.web
+aws_instance.web
+aws_load_balancer.weblb
+aws_security_group.firewall
+openstack_floating_ip.random
+`)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+func TestConfigTransformer_unique(t *testing.T) {
+	addr, err := ParseResourceAddress("aws_instance.web")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	g := Graph{Path: RootModulePath}
+	g.Add(&NodeAbstractResource{Addr: addr})
+	tf := &ConfigTransformer{
+		Module: testModule(t, "graph-basic"),
+		Unique: true,
+	}
+	if err := tf.Transform(&g); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(`
+aws_instance.web
+aws_load_balancer.weblb
+aws_security_group.firewall
+openstack_floating_ip.random
+`)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
 const testConfigTransformerGraphBasicStr = `
 aws_instance.web
 aws_load_balancer.weblb