packer/rpc: implement new warnings interfaces

packer/rpc/build.go

@@ -21,6 +21,11 @@ type BuildRunArgs struct {
 	UiRPCAddress string
 }
 
+type BuildPrepareResponse struct {
+	Warnings []string
+	Error    error
+}
+
 func Build(client *rpc.Client) *build {
 	return &build{client}
 }
@@ -30,12 +35,13 @@ func (b *build) Name() (result string) {
 	return
 }
 
-func (b *build) Prepare(v map[string]string) (err error) {
-	if cerr := b.client.Call("Build.Prepare", v, &err); cerr != nil {
-		return cerr
+func (b *build) Prepare(v map[string]string) ([]string, error) {
+	var resp BuildPrepareResponse
+	if cerr := b.client.Call("Build.Prepare", v, &resp); cerr != nil {
+		return nil, cerr
 	}
 
-	return
+	return resp.Warnings, resp.Error
 }
 
 func (b *build) Run(ui packer.Ui, cache packer.Cache) ([]packer.Artifact, error) {
@@ -86,8 +92,12 @@ func (b *BuildServer) Name(args *interface{}, reply *string) error {
 	return nil
 }
 
-func (b *BuildServer) Prepare(v map[string]string, reply *error) error {
-	*reply = b.build.Prepare(v)
+func (b *BuildServer) Prepare(v map[string]string, resp *BuildPrepareResponse) error {
+	warnings, err := b.build.Prepare(v)
+	*resp = BuildPrepareResponse{
+		Warnings: warnings,
+		Error:    err,
+	}
 	return nil
 }
 

packer/rpc/build_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"github.com/mitchellh/packer/packer"
 	"net/rpc"
+	"reflect"
 	"testing"
 )
 
@@ -13,6 +14,7 @@ type testBuild struct {
 	nameCalled      bool
 	prepareCalled   bool
 	prepareVars     map[string]string
+	prepareWarnings []string
 	runCalled       bool
 	runCache        packer.Cache
 	runUi           packer.Ui
@@ -28,10 +30,10 @@ func (b *testBuild) Name() string {
 	return "name"
 }
 
-func (b *testBuild) Prepare(v map[string]string) error {
+func (b *testBuild) Prepare(v map[string]string) ([]string, error) {
 	b.prepareCalled = true
 	b.prepareVars = v
-	return nil
+	return b.prepareWarnings, nil
 }
 
 func (b *testBuild) Run(ui packer.Ui, cache packer.Cache) ([]packer.Artifact, error) {
@@ -58,7 +60,7 @@ func (b *testBuild) Cancel() {
 	b.cancelCalled = true
 }
 
-func TestBuildRPC(t *testing.T) {
+func buildRPCClient(t *testing.T) (*testBuild, packer.Build) {
 	// Create the interface to test
 	b := new(testBuild)
 
@@ -72,7 +74,11 @@ func TestBuildRPC(t *testing.T) {
 	if err != nil {
 		t.Fatalf("err: %s", err)
 	}
-	bClient := Build(client)
+	return b, Build(client)
+}
+
+func TestBuild(t *testing.T) {
+	b, bClient := buildRPCClient(t)
 
 	// Test Name
 	bClient.Name()
@@ -157,6 +163,21 @@ func TestBuildRPC(t *testing.T) {
 	}
 }
 
+func TestBuildPrepare_Warnings(t *testing.T) {
+	b, bClient := buildRPCClient(t)
+
+	expected := []string{"foo"}
+	b.prepareWarnings = expected
+
+	warnings, err := bClient.Prepare(nil)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if !reflect.DeepEqual(warnings, expected) {
+		t.Fatalf("bad: %#v", warnings)
+	}
+}
+
 func TestBuild_ImplementsBuild(t *testing.T) {
 	var _ packer.Build = Build(nil)
 }

packer/rpc/builder.go

@@ -29,6 +29,11 @@ type BuilderRunArgs struct {
 	ResponseAddress string
 }
 
+type BuilderPrepareResponse struct {
+	Warnings []string
+	Error    error
+}
+
 type BuilderRunResponse struct {
 	Err        error
 	RPCAddress string
@@ -38,13 +43,14 @@ func Builder(client *rpc.Client) *builder {
 	return &builder{client}
 }
 
-func (b *builder) Prepare(config ...interface{}) (err error) {
-	cerr := b.client.Call("Builder.Prepare", &BuilderPrepareArgs{config}, &err)
+func (b *builder) Prepare(config ...interface{}) ([]string, error) {
+	var resp BuilderPrepareResponse
+	cerr := b.client.Call("Builder.Prepare", &BuilderPrepareArgs{config}, &resp)
 	if cerr != nil {
-		err = cerr
+		return nil, cerr
 	}
 
-	return
+	return resp.Warnings, resp.Error
 }
 
 func (b *builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
@@ -108,12 +114,16 @@ func (b *builder) Cancel() {
 	}
 }
 
-func (b *BuilderServer) Prepare(args *BuilderPrepareArgs, reply *error) error {
-	err := b.builder.Prepare(args.Configs...)
+func (b *BuilderServer) Prepare(args *BuilderPrepareArgs, reply *BuilderPrepareResponse) error {
+	warnings, err := b.builder.Prepare(args.Configs...)
 	if err != nil {
-		*reply = NewBasicError(err)
+		err = NewBasicError(err)
 	}
 
+	*reply = BuilderPrepareResponse{
+		Warnings: warnings,
+		Error:    err,
+	}
 	return nil
 }
 

packer/rpc/builder_test.go

@@ -23,10 +23,10 @@ type testBuilder struct {
 	nilRunResult bool
 }
 
-func (b *testBuilder) Prepare(config ...interface{}) error {
+func (b *testBuilder) Prepare(config ...interface{}) ([]string, error) {
 	b.prepareCalled = true
 	b.prepareConfig = config
-	return nil
+	return nil, nil
 }
 
 func (b *testBuilder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {