helper/schema: Resource.Refresh

Author: mitchellh

helper/schema/provider.go

@@ -17,10 +17,15 @@ type Provider struct {
 	ResourcesMap map[string]*Resource
 
 	ConfigureFunc ConfigureFunc
+
+	meta interface{}
 }
 
 // ConfigureFunc is the function used to configure a Provider.
-type ConfigureFunc func(*ResourceData) error
+//
+// The interface{} value returned by this function is stored and passed into
+// the subsequent resources as the meta parameter.
+type ConfigureFunc func(*ResourceData) (interface{}, error)
 
 // Validate validates the provider configuration against the schema.
 func (p *Provider) Validate(c *terraform.ResourceConfig) ([]string, []error) {
@@ -61,7 +66,13 @@ func (p *Provider) Configure(c *terraform.ResourceConfig) error {
 		return err
 	}
 
-	return p.ConfigureFunc(data)
+	meta, err := p.ConfigureFunc(data)
+	if err != nil {
+		return err
+	}
+
+	p.meta = meta
+	return nil
 }
 
 // Resources implementation of terraform.ResourceProvider interface.

helper/schema/provider_test.go

@@ -30,12 +30,12 @@ func TestProviderConfigure(t *testing.T) {
 					},
 				},
 
-				ConfigureFunc: func(d *ResourceData) error {
+				ConfigureFunc: func(d *ResourceData) (interface{}, error) {
 					if d.Get("foo").(int) == 42 {
-						return nil
+						return nil, nil
 					}
 
-					return fmt.Errorf("nope")
+					return nil, fmt.Errorf("nope")
 				},
 			},
 			Config: map[string]interface{}{
@@ -53,12 +53,12 @@ func TestProviderConfigure(t *testing.T) {
 					},
 				},
 
-				ConfigureFunc: func(d *ResourceData) error {
+				ConfigureFunc: func(d *ResourceData) (interface{}, error) {
 					if d.Get("foo").(int) == 42 {
-						return nil
+						return nil, nil
 					}
 
-					return fmt.Errorf("nope")
+					return nil, fmt.Errorf("nope")
 				},
 			},
 			Config: map[string]interface{}{

helper/schema/resource.go

@@ -7,10 +7,13 @@ import (
 )
 
 // The functions below are the CRUD function types for a Resource.
-type CreateFunc func(*ResourceData) error
-type ReadFunc func(*ResourceData) error
-type UpdateFunc func(*ResourceData) error
-type DeleteFunc func(*ResourceData) error
+//
+// The second parameter is the meta value sent to the resource when
+// different operations are called.
+type CreateFunc func(*ResourceData, interface{}) error
+type ReadFunc func(*ResourceData, interface{}) error
+type UpdateFunc func(*ResourceData, interface{}) error
+type DeleteFunc func(*ResourceData, interface{}) error
 
 // Resource represents a thing in Terraform that has a set of configurable
 // attributes and generally also has a lifecycle (create, read, update,
@@ -41,6 +44,19 @@ func (r *Resource) Validate(c *terraform.ResourceConfig) ([]string, []error) {
 	return schemaMap(r.Schema).Validate(c)
 }
 
+// Refresh refreshes the state of the resource.
+func (r *Resource) Refresh(
+	s *terraform.ResourceState,
+	meta interface{}) (*terraform.ResourceState, error) {
+	data, err := schemaMap(r.Schema).Data(s, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	err = r.Read(data, meta)
+	return data.State(), err
+}
+
 // InternalValidate should be called to validate the structure
 // of the resource.
 //

helper/schema/resource_data.go

@@ -14,7 +14,9 @@ type ResourceData struct {
 	schema map[string]*Schema
 	state  *terraform.ResourceState
 	diff   *terraform.ResourceDiff
-	setMap map[string]string
+
+	setMap   map[string]string
+	newState *terraform.ResourceState
 }
 
 // Get returns the data for the given key, or nil if the key doesn't exist.
@@ -49,6 +51,15 @@ func (d *ResourceData) Set(key string, value interface{}) error {
 func (d *ResourceData) State() *terraform.ResourceState {
 	var result terraform.ResourceState
 	result.Attributes = d.stateObject("", d.schema)
+
+	if d.state != nil {
+		result.ID = d.state.ID
+	}
+
+	if d.newState != nil {
+		result.ID = d.newState.ID
+	}
+
 	return &result
 }
 
@@ -335,7 +346,7 @@ func (d *ResourceData) stateList(
 	count := countRaw.(int)
 
 	result := make(map[string]string)
-	result[prefix + ".#"] = strconv.FormatInt(int64(count), 10)
+	result[prefix+".#"] = strconv.FormatInt(int64(count), 10)
 	for i := 0; i < count; i++ {
 		key := fmt.Sprintf("%s.%d", prefix, i)
 

helper/schema/resource_test.go

@@ -1,7 +1,11 @@
 package schema
 
 import (
+	"fmt"
+	"reflect"
 	"testing"
+
+	"github.com/hashicorp/terraform/terraform"
 )
 
 func TestResourceInternalValidate(t *testing.T) {
@@ -36,3 +40,45 @@ func TestResourceInternalValidate(t *testing.T) {
 		}
 	}
 }
+
+func TestResourceRefresh(t *testing.T) {
+	r := &Resource{
+		Schema: map[string]*Schema{
+			"foo": &Schema{
+				Type:     TypeInt,
+				Optional: true,
+			},
+		},
+	}
+
+	r.Read = func(d *ResourceData, m interface{}) error {
+		if m != 42 {
+			return fmt.Errorf("meta not passed")
+		}
+
+		return d.Set("foo", d.Get("foo").(int)+1)
+	}
+
+	s := &terraform.ResourceState{
+		ID: "bar",
+		Attributes: map[string]string{
+			"foo": "12",
+		},
+	}
+
+	expected := &terraform.ResourceState{
+		ID: "bar",
+		Attributes: map[string]string{
+			"foo": "13",
+		},
+	}
+
+	actual, err := r.Refresh(s, 42)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Fatalf("bad: %#v", actual)
+	}
+}