Support downloading remote tarball contexts in builder jobs.

Signed-off-by: Moysés Borges <moysesb@gmail.com>

integration-cli/docker_utils.go

@@ -632,6 +632,10 @@ type FakeContext struct {
 }
 
 func (f *FakeContext) Add(file, content string) error {
+	return f.addFile(file, []byte(content))
+}
+
+func (f *FakeContext) addFile(file string, content []byte) error {
 	filepath := path.Join(f.Dir, file)
 	dirpath := path.Dir(filepath)
 	if dirpath != "." {
@@ -639,7 +643,8 @@ func (f *FakeContext) Add(file, content string) error {
 			return err
 		}
 	}
-	return ioutil.WriteFile(filepath, []byte(content), 0644)
+	return ioutil.WriteFile(filepath, content, 0644)
+
 }
 
 func (f *FakeContext) Delete(file string) error {
@@ -651,11 +656,7 @@ func (f *FakeContext) Close() error {
 	return os.RemoveAll(f.Dir)
 }
 
-func fakeContextFromDir(dir string) *FakeContext {
-	return &FakeContext{dir}
-}
-
-func fakeContextWithFiles(files map[string]string) (*FakeContext, error) {
+func fakeContextFromNewTempDir() (*FakeContext, error) {
 	tmp, err := ioutil.TempDir("", "fake-context")
 	if err != nil {
 		return nil, err
@@ -663,8 +664,18 @@ func fakeContextWithFiles(files map[string]string) (*FakeContext, error) {
 	if err := os.Chmod(tmp, 0755); err != nil {
 		return nil, err
 	}
+	return fakeContextFromDir(tmp), nil
+}
 
-	ctx := fakeContextFromDir(tmp)
+func fakeContextFromDir(dir string) *FakeContext {
+	return &FakeContext{dir}
+}
+
+func fakeContextWithFiles(files map[string]string) (*FakeContext, error) {
+	ctx, err := fakeContextFromNewTempDir()
+	if err != nil {
+		return nil, err
+	}
 	for file, content := range files {
 		if err := ctx.Add(file, content); err != nil {
 			ctx.Close()
@@ -701,6 +712,19 @@ type FakeStorage interface {
 	CtxDir() string
 }
 
+func fakeBinaryStorage(archives map[string]*bytes.Buffer) (FakeStorage, error) {
+	ctx, err := fakeContextFromNewTempDir()
+	if err != nil {
+		return nil, err
+	}
+	for name, content := range archives {
+		if err := ctx.addFile(name, content.Bytes()); err != nil {
+			return nil, err
+		}
+	}
+	return fakeStorageWithContext(ctx)
+}
+
 // fakeStorage returns either a local or remote (at daemon machine) file server
 func fakeStorage(files map[string]string) (FakeStorage, error) {
 	ctx, err := fakeContextWithFiles(files)