Move packages to proejct/pkg to follow go project folder structure convention (#1190)

cmd/builder/main.go

@@ -0,0 +1,48 @@
+/*
+Copyright 2018 The Fission Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"log"
+	"os"
+
+	"go.uber.org/zap"
+
+	"github.com/fission/fission/cmd/builder/app"
+)
+
+// Usage: builder <shared volume path>
+func main() {
+	logger, err := zap.NewProduction()
+	if err != nil {
+		log.Fatalf("can't initialize zap logger: %v", err)
+	}
+	defer logger.Sync()
+
+	shareVolume := os.Args[1]
+	if _, err := os.Stat(shareVolume); err != nil {
+		if os.IsNotExist(err) {
+			err = os.MkdirAll(shareVolume, os.ModeDir|0700)
+			if err != nil {
+				logger.Fatal("error creating directory: %v", zap.Error(err), zap.String("directory", shareVolume))
+			}
+		}
+	}
+
+	err = app.Run(logger, shareVolume)
+	logger.Error("error running builder", zap.Error(err))
+}