main.go

由于alpine镜像缺少时区文件，下面代码运行会报错
```
func init() {
    # set global time location
	location, e := time.LoadLocation("Asia/Shanghai")
	if e != nil {
		log.Printf("load location error:%s", e)
		os.Exit(1)
	}
	time.Local = location
}
```

Dockerfile

```
FROM alpine:latest

MAINTAINER ZhouChang "zhouchangqaz@gmail.com"

# 设置时区为上海
RUN apk --no-cache add tzdata  && \
    ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && \
    echo "Asia/Shanghai" > /etc/timezone


ADD ./bin/product_srv /usr/local/bin/

ENTRYPOINT ["/usr/local/bin/product_srv"]
```