move tar writer close

common/docker/docker.go

@@ -291,9 +291,12 @@ func pullImageIfNotExists(ctx context.Context, cli *client.Client, imageName str
 
 func buildImage(ctx context.Context, cli *client.Client, dockerfile Dockerfile, imageName string) error {
 	fmt.Println("Building image ", imageName)
+
+	// Enable BuildKit via environment variable
+	os.Setenv("DOCKER_BUILDKIT", "1")
+
 	buf := new(bytes.Buffer)
 	tw := tar.NewWriter(buf)
-	defer tw.Close()
 
 	// Add the Dockerfile to the tar archive
 	header := &tar.Header{
@@ -312,8 +315,13 @@ func buildImage(ctx context.Context, cli *client.Client, dockerfile Dockerfile,
 		return err
 	}
 
+	if err := tw.Close(); err != nil {
+		return eris.Wrap(err, "Failed to close tar writer")
+	}
+
 	// Read the tar archive
-	tarReader := bytes.NewReader(buf.Bytes())
+	buildContext := io.NopCloser(bytes.NewReader(buf.Bytes()))
+	defer buildContext.Close()
 
 	buildOptions := types.ImageBuildOptions{
 		Dockerfile: "Dockerfile",
@@ -323,7 +331,7 @@ func buildImage(ctx context.Context, cli *client.Client, dockerfile Dockerfile,
 	}
 
 	// Build the image
-	buildResponse, err := cli.ImageBuild(ctx, tarReader, buildOptions)
+	buildResponse, err := cli.ImageBuild(ctx, buildContext, buildOptions)
 	if err != nil {
 		return err
 	}