Update DescribeResources signature

Signed-off-by: Noah Treuhaft <noah.treuhaft@docker.com>

cmd/cli/resource.go

@@ -25,6 +25,14 @@ func resourceCommand(plugins func() discovery.Plugins) *cobra.Command {
 		Short: "Access resource plugin",
 	}
 	cmd.PersistentPreRunE = func(c *cobra.Command, args []string) error {
+		if err := upTree(c, func(x *cobra.Command, argv []string) error {
+			if x.PersistentPreRunE != nil {
+				return x.PersistentPreRunE(x, argv)
+			}
+			return nil
+		}); err != nil {
+			return err
+		}
 
 		plugins, err := discovery.NewPluginDiscovery()
 		if err != nil {
@@ -65,7 +73,12 @@ func resourceCommand(plugins func() discovery.Plugins) *cobra.Command {
 		if err != nil {
 			return err
 		}
-		view, err := engine.AddFunc("resource", resourceIdentityFunc).Render(nil)
+
+		engine.WithFunctions(func() []template.Function {
+			return []template.Function{{Name: "resource", Func: resourceFunc}}
+		})
+
+		view, err := engine.Render(nil)
 		if err != nil {
 			return err
 		}
@@ -112,7 +125,12 @@ func resourceCommand(plugins func() discovery.Plugins) *cobra.Command {
 		if err != nil {
 			return err
 		}
-		view, err := engine.AddFunc("resource", resourceIdentityFunc).Render(nil)
+
+		engine.WithFunctions(func() []template.Function {
+			return []template.Function{{Name: "resource", Func: resourceFunc}}
+		})
+
+		view, err := engine.Render(nil)
 		if err != nil {
 			return err
 		}
@@ -140,6 +158,6 @@ func resourceCommand(plugins func() discovery.Plugins) *cobra.Command {
 	return cmd
 }
 
-func resourceIdentityFunc(name string) string {
-	return fmt.Sprintf("{{ resource `%s` }}", name)
+func resourceFunc(s string) string {
+	return fmt.Sprintf("{{ resource `%s` }}", s)
 }

pkg/plugin/resource/resource.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"sort"
+	"strings"
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/docker/infrakit/pkg/discovery"
@@ -157,8 +158,24 @@ func (p *plugin) Destroy(config resource.Spec, pretend bool) (string, error) {
 	return desc, nil
 }
 
-func (p *plugin) DescribeResources() ([]instance.Description, error) {
-	return nil, errors.New("unimplemented")
+func (p *plugin) DescribeResources(config resource.Spec) (string, error) {
+	spec, _, err := validate(config, p.instancePluginLookup)
+	if err != nil {
+		return "", err
+	}
+
+	ids, err := describe(config.ID, *spec)
+	if err != nil {
+		return "", err
+	}
+
+	details := []string{}
+	for name, id := range ids {
+		details = append(details, fmt.Sprintf("Found %s (ID %s)", name, id))
+	}
+	sort.Strings(details)
+
+	return strings.Join(details, "\n"), nil
 }
 
 func describe(configID resource.ID, spec Spec) (map[string]instance.ID, error) {

pkg/plugin/resource/resource_test.go

@@ -41,16 +41,16 @@ func newTestInstancePlugin() *testing_instance.Plugin {
 		DoDescribeInstances: func(tags map[string]string) ([]instance.Description, error) {
 			descriptions := []instance.Description{}
 		Loop:
-			for id, instnc := range instances {
+			for id, inst := range instances {
 				for k, v := range tags {
-					if v2, ok := instnc.Tags[k]; !ok || v2 != v {
+					if v2, ok := inst.Tags[k]; !ok || v2 != v {
 						continue Loop
 					}
 				}
 				descriptions = append(descriptions, instance.Description{
 					ID:        id,
-					LogicalID: instnc.LogicalID,
-					Tags:      instnc.Tags,
+					LogicalID: inst.LogicalID,
+					Tags:      inst.Tags,
 				})
 			}
 			return descriptions, nil
@@ -75,9 +75,9 @@ func TestCommitAndDestroy(t *testing.T) {
 	properties := types.AnyString(
 		`{"Resources": {"a": {"Plugin": "pluginA", "Properties": "{{ resource ` + "`b`" + ` }}"}, "b": {"Plugin": "pluginB", "Properties": ""}}}`)
 
-	const specID = "config"
+	const configID = "config"
 	spec := resource.Spec{
-		ID:         specID,
+		ID:         configID,
 		Properties: properties,
 	}
 
@@ -103,15 +103,15 @@ func TestCommitAndDestroy(t *testing.T) {
 
 	require.NotEqual(t, "", descriptions[0].ID)
 	require.Nil(t, descriptions[0].LogicalID)
-	require.Equal(t, map[string]string{resourceGroupTag: specID, resourceNameTag: "a"}, descriptions[0].Tags)
+	require.Equal(t, map[string]string{resourceGroupTag: configID, resourceNameTag: "a"}, descriptions[0].Tags)
 
 	descriptions, err = instancePluginB.DescribeInstances(nil)
 	require.NoError(t, err)
 	require.Len(t, descriptions, 1)
 
 	require.NotEqual(t, "", descriptions[0].ID)
 	require.Nil(t, descriptions[0].LogicalID)
-	require.Equal(t, map[string]string{resourceGroupTag: specID, resourceNameTag: "b"}, descriptions[0].Tags)
+	require.Equal(t, map[string]string{resourceGroupTag: configID, resourceNameTag: "b"}, descriptions[0].Tags)
 
 	// Commit with the same specification should create no additional resources.
 	_, err = p.Commit(spec, false)
@@ -155,8 +155,25 @@ func TestCommitAndDestroy(t *testing.T) {
 }
 
 func TestDescribeResources(t *testing.T) {
-	_, err := NewResourcePlugin(nil).DescribeResources()
-	require.Error(t, err)
+	const configID = "config"
+	instancePlugin := newTestInstancePlugin()
+	p := NewResourcePlugin(func(name plugin_base.Name) (instance.Plugin, error) {
+		return instancePlugin, nil
+	})
+
+	aID, err := instancePlugin.Provision(instance.Spec{Tags: map[string]string{resourceGroupTag: configID, resourceNameTag: "a"}})
+	require.NoError(t, err)
+	bID, err := instancePlugin.Provision(instance.Spec{Tags: map[string]string{resourceGroupTag: configID, resourceNameTag: "b"}})
+	require.NoError(t, err)
+
+	properties := types.AnyString(`{"Resources": {"a": {"Plugin": "p", "Properties": ""}, "b": {"Plugin": "p", "Properties": ""}}}`)
+	spec := resource.Spec{
+		ID:         configID,
+		Properties: properties,
+	}
+	details, err := p.DescribeResources(spec)
+	require.NoError(t, err)
+	require.Equal(t, fmt.Sprintf("Found a (ID %s)\nFound b (ID %s)", string(*aID), string(*bID)), details)
 }
 
 func TestDescribe(t *testing.T) {

pkg/spi/resource/spi.go

@@ -2,7 +2,6 @@ package resource
 
 import (
 	"github.com/docker/infrakit/pkg/spi"
-	"github.com/docker/infrakit/pkg/spi/instance"
 	"github.com/docker/infrakit/pkg/types"
 )
 
@@ -12,11 +11,12 @@ var InterfaceSpec = spi.InterfaceSpec{
 	Version: "0.1.0",
 }
 
-// ID is the unique identifier for a collection of resources.
+// ID is a unique identifier for a collection of resources.
 type ID string
 
 // Spec is a specification of resources to provision.
 type Spec struct {
+
 	// ID is the unique identifier for the collection of resources.
 	ID ID
 
@@ -26,7 +26,7 @@ type Spec struct {
 
 // Plugin defines the functions for a Resource plugin.
 type Plugin interface {
-	Commit(spec Spec, pretend bool) (plan string, err error)
-	Destroy(spec Spec, pretend bool) (plan string, err error)
-	DescribeResources() ([]instance.Description, error)
+	Commit(spec Spec, pretend bool) (string, error)
+	Destroy(spec Spec, pretend bool) (string, error)
+	DescribeResources(spec Spec) (string, error)
 }