packer: Environment can look up post processors

packer/environment.go

@@ -19,6 +19,9 @@ type CommandFunc func(name string) (Command, error)
 // The function type used to lookup Hook implementations.
 type HookFunc func(name string) (Hook, error)
 
+// The function type used to lookup PostProcessor implementations.
+type PostProcessorFunc func(name string) (PostProcessor, error)
+
 // The function type used to lookup Provisioner implementations.
 type ProvisionerFunc func(name string) (Provisioner, error)
 
@@ -26,10 +29,11 @@ type ProvisionerFunc func(name string) (Provisioner, error)
 // pointers necessary to look up components of Packer such as builders,
 // commands, etc.
 type ComponentFinder struct {
-	Builder     BuilderFunc
-	Command     CommandFunc
-	Hook        HookFunc
-	Provisioner ProvisionerFunc
+	Builder       BuilderFunc
+	Command       CommandFunc
+	Hook          HookFunc
+	PostProcessor PostProcessorFunc
+	Provisioner   ProvisionerFunc
 }
 
 // The environment interface provides access to the configuration and
@@ -42,6 +46,7 @@ type Environment interface {
 	Cache() Cache
 	Cli([]string) (int, error)
 	Hook(string) (Hook, error)
+	PostProcessor(string) (PostProcessor, error)
 	Provisioner(string) (Provisioner, error)
 	Ui() Ui
 }
@@ -104,6 +109,10 @@ func NewEnvironment(config *EnvironmentConfig) (resultEnv Environment, err error
 		env.components.Hook = func(string) (Hook, error) { return nil, nil }
 	}
 
+	if env.components.PostProcessor == nil {
+		env.components.PostProcessor = func(string) (PostProcessor, error) { return nil, nil }
+	}
+
 	if env.components.Provisioner == nil {
 		env.components.Provisioner = func(string) (Provisioner, error) { return nil, nil }
 	}
@@ -152,6 +161,21 @@ func (e *coreEnvironment) Hook(name string) (h Hook, err error) {
 	return
 }
 
+// Returns a PostProcessor for the given name that is registered with this
+// environment.
+func (e *coreEnvironment) PostProcessor(name string) (p PostProcessor, err error) {
+	p, err = e.components.PostProcessor(name)
+	if err != nil {
+		return
+	}
+
+	if p == nil {
+		err = fmt.Errorf("No post processor found for name: %s", name)
+	}
+
+	return
+}
+
 // Returns a provisioner for the given name that is registered with this
 // environment.
 func (e *coreEnvironment) Provisioner(name string) (p Provisioner, err error) {

packer/environment_test.go

@@ -67,6 +67,7 @@ func TestEnvironment_NilComponents(t *testing.T) {
 	env.Builder("foo")
 	env.Cli([]string{"foo"})
 	env.Hook("foo")
+	env.PostProcessor("foo")
 	env.Provisioner("foo")
 }
 
@@ -246,6 +247,47 @@ func TestEnvironment_Hook_Error(t *testing.T) {
 	assert.Nil(returned, "should be no hook")
 }
 
+func TestEnvironment_PostProcessor(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	pp := &TestPostProcessor{}
+	pps := make(map[string]PostProcessor)
+	pps["foo"] = pp
+
+	config := DefaultEnvironmentConfig()
+	config.Components.PostProcessor = func(n string) (PostProcessor, error) { return pps[n], nil }
+
+	env, _ := NewEnvironment(config)
+	returned, err := env.PostProcessor("foo")
+	assert.Nil(err, "should be no error")
+	assert.Equal(returned, pp, "should return correct pp")
+}
+
+func TestEnvironment_PostProcessor_NilError(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	config := DefaultEnvironmentConfig()
+	config.Components.PostProcessor = func(n string) (PostProcessor, error) { return nil, nil }
+
+	env, _ := NewEnvironment(config)
+	returned, err := env.PostProcessor("foo")
+	assert.NotNil(err, "should be an error")
+	assert.Nil(returned, "should be no pp")
+}
+
+func TestEnvironment_PostProcessor_Error(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	config := DefaultEnvironmentConfig()
+	config.Components.PostProcessor = func(n string) (PostProcessor, error) { return nil, errors.New("foo") }
+
+	env, _ := NewEnvironment(config)
+	returned, err := env.PostProcessor("foo")
+	assert.NotNil(err, "should be an error")
+	assert.Equal(err.Error(), "foo", "should be correct error")
+	assert.Nil(returned, "should be no pp")
+}
+
 func TestEnvironmentProvisioner(t *testing.T) {
 	assert := asserts.NewTestingAsserts(t, true)
 

packer/post_processor_test.go

@@ -0,0 +1,11 @@
+package packer
+
+type TestPostProcessor struct{}
+
+func (*TestPostProcessor) Configure(interface{}) error {
+	return nil
+}
+
+func (*TestPostProcessor) PostProcess(Artifact) (Artifact, error) {
+	return nil, nil
+}