利用docker多阶段构建镜像的机制，可以使构建出来的最终镜像体积大大减小，从而方便传输
比如我们使用go语言构建程序，在编译环境需要安装go等一些依赖，而构建出来的二进制文件只需要在一个很小的Linux容器中即可运行
CentOS Linux release 7.9.2009 (Core)
go version go1.15.5 linux/amd64
Docker version 18.09.9, build 039a7df9ba
#1 安装docker
https://blog.csdn.net/xys2015/article/details/109370082
#2 安装go
https://blog.csdn.net/xys2015/article/details/113770562
1 目标
2 书写代码
package main
import (
"fmt"
"log"
"net/http"
)
// HelloServer responds to requests with the given URL path.
func HelloServer(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Hello, you requested: %s\n", r.URL.Path)
log.Printf("Received request for path: %s", r.URL.Path)
}
func main() {
var addr string = ":8180"
handler := http.HandlerFunc(HelloServer)
if err := http.ListenAndServe(addr, handler); err != nil {
log.Fatalf("Could not listen on port %s %v", addr, err)
}
}
3 编译
go build hello.go
3 运行
./hello
4 访问
[root@192_168_31_100 ~]# curl localhost:8180/xxx
Hello, you requested: /xxx
[root@192_168_31_100 ~]# curl localhost:8180/hello
Hello, you requested: /hello
[root@192_168_31_100 ~]# curl localhost:8180/world
Hello, you requested: /world
5 查看输出的日志
[root@192_168_31_100 /data/gitee-dld/hello-go/http-server]# ./hello
2021/02/09 15:26:32 Received request for path: /xxx
2021/02/09 15:26:35 Received request for path: /hello
2021/02/09 15:26:39 Received request for path: /world
6 结束程序
CTRL + C
参考地址 https://gitee.com/as4k/gitee-dld/tree/master/hello-go/http-server
1 书写 Dockerfile
cat Dockerfile
FROM golang:1-alpine as build
# golang:1-alpine 这个标签的含义是 最新1.x版本，基础镜像是 alpine linux
WORKDIR /app
COPY http-server http-server
RUN go build /app/http-server/hello.go
#这里生成的二进制文件会放在 /app/hello
FROM alpine:latest
WORKDIR /app
COPY --from=build /app/hello /app/hello
#--from=build 这里即用到第一阶段的镜像
EXPOSE 8180
ENTRYPOINT ["./hello"]
2 构建镜像
#处在Dockerfile所在目录下
docker build -t hello-go:v1 .
3 运行容器
docker run -d --name hello-go --rm -p 8180:8180 hello-go:v1
4 访问容器
curl localhost:8180/hello-world
5 相关输出信息
5.1 镜像大小对比
====================
# docker images | egrep "hello|golang"
hello-go v1 abe1c3a706e0 About a minute ago 12.1MB
golang 1-alpine 1463476d8605 7 weeks ago 299MB
可以看到，节省了不少磁盘空间，如果go程序有大量依赖，效果更明显
5.2 容器运行信息和访问信息
====================
[root@192_168_31_100 /data/gitee-dld/hello-go]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e964f390ac91 hello-go:v1 "./hello" 2 seconds ago Up 1 second 0.0.0.0:8180->8180/tcp hello-go
[root@192_168_31_100 /data/gitee-dld/hello-go]# curl localhost:8180/hello-world
Hello, you requested: /hello-world