前言

cli is a simple, fast, and fun package for building command line apps in Go. 官网

例子1

package main

import (
    "log"
    "os"
    "time"

    "github.com/urfave/cli"
)

func main() {
    log.Printf("Main start!\n")
    app := cli.NewApp()
    app.Name = "example"
    app.Usage = "make an explosive entrance"
    app.Action = func(c *cli.Context) error {
        log.Printf("args:%s\n", c.Args())
        for i := 0; i < 5; i++ {
            log.Printf("sleep %d\n", i)
            time.Sleep(1 * time.Second)
        }
        return nil
    }

    log.Printf("Before invoking Run!\n")
    err := app.Run(os.Args)
    if err != nil {
        log.Fatal(err)
    }
    log.Printf("Main end!\n")
}

go run test01.go args01 args02
运行结果:

2019/03/24 18:41:58 Main start!
2019/03/24 18:41:58 Before invoking Run!
2019/03/24 18:41:58 args:[args01 args02]
2019/03/24 18:41:58 sleep 0
2019/03/24 18:41:59 sleep 1
2019/03/24 18:42:00 sleep 2
2019/03/24 18:42:01 sleep 3
2019/03/24 18:42:02 sleep 4
2019/03/24 18:42:03 Main end!

可以看到app.Run(os.Args)是会阻塞的.

例子2

加入Flag

package main

import (
    "log"
    "os"
    "time"

    "github.com/urfave/cli"
)

func main() {
    log.Printf("Main start!\n")
    app := cli.NewApp()
    app.Name = "example"
    app.Usage = "make an explosive entrance"

    app.Flags = []cli.Flag {
        cli.BoolFlag{
            Name: "flag",
            Usage: "enable tty",
        },
        cli.StringFlag{
            Name: "lang",
            Value: "english",
        },
    }

    app.Action = func(c *cli.Context) error {
        log.Printf("args:%s\n", c.Args())
        log.Printf("flag:%v\n", c.Bool("flag"))
        log.Printf("lang:%s\n", c.String("lang"))
        for i := 0; i < 5; i++ {
            log.Printf("sleep %d\n", i)
            time.Sleep(1 * time.Second)
        }
        return nil
    }

    log.Printf("Before invoking Run!\n")
    err := app.Run(os.Args)
    if err != nil {
        log.Fatal(err)
    }
    log.Printf("Main end!\n")
}

go run test02.go -flag -lang chinese args01 args02

2019/03/24 19:30:13 Main start!
2019/03/24 19:30:13 Before invoking Run!
2019/03/24 19:30:13 args:[args01 args02]
2019/03/24 19:30:13 flag:true
2019/03/24 19:30:13 lang:chinese
2019/03/24 19:30:13 sleep 0
2019/03/24 19:30:14 sleep 1
2019/03/24 19:30:15 sleep 2
2019/03/24 19:30:16 sleep 3
2019/03/24 19:30:17 sleep 4
2019/03/24 19:30:18 Main end!

例子3

加入Command

package main

import (
    "log"
    "os"
    "time"

    "github.com/urfave/cli"
)

func main() {
    log.Printf("Main start!\n")
    app := cli.NewApp()
    app.Name = "example"
    app.Usage = "make an explosive entrance"

    runCommand := cli.Command{
        Name: "run",
        Flags: []cli.Flag{
            cli.BoolFlag{
                Name: "it",
                Usage: "enable tty",
            },
        },
        Action: func(c *cli.Context) error {
            log.Printf("runcommand args:%s\n", c.Args())
            log.Printf("runcommand tty:%v\n", c.Bool("it"))
            for i := 0; i < 5; i++ {
                log.Printf("runcommand sleep %d\n", i)
                time.Sleep(1 * time.Second)
            }
            return nil
        },
    }

    app.Commands = []cli.Command {
        runCommand,
    }

    app.Action = func(c *cli.Context) error {
        log.Printf("main function args:%s\n", c.Args())
        for i := 0; i < 5; i++ {
            log.Printf("main function sleep %d\n", i)
            time.Sleep(1 * time.Second)
        }
        return nil
    }

    log.Printf("Before invoking Run!\n")
    err := app.Run(os.Args)
    if err != nil {
        log.Fatal(err)
    }
    log.Printf("Main end!\n")
}

go run test03.go run -it arg01 arg02

2019/03/24 19:45:50 Main start!
2019/03/24 19:45:50 Before invoking Run!
2019/03/24 19:45:50 runcommand args:[arg01 arg02]
2019/03/24 19:45:50 runcommand tty:true
2019/03/24 19:45:50 runcommand sleep 0
2019/03/24 19:45:51 runcommand sleep 1
2019/03/24 19:45:52 runcommand sleep 2
2019/03/24 19:45:53 runcommand sleep 3
2019/03/24 19:45:54 runcommand sleep 4
2019/03/24 19:45:55 Main end!

参考

1. https://github.com/urfave/cli

全部内容

mydocker.png

1. [mydocker]---环境说明
2. [mydocker]---urfave cli 理解
3. [mydocker]---Linux Namespace
4. [mydocker]---Linux Cgroup
5. [mydocker]---构造容器01-实现run命令
6. [mydocker]---构造容器02-实现资源限制01
7. [mydocker]---构造容器02-实现资源限制02
8. [mydocker]---构造容器03-实现增加管道
9. [mydocker]---通过例子理解存储驱动AUFS
10. [mydocker]---通过例子理解chroot 和 pivot_root
11. [mydocker]---一步步实现使用busybox创建容器
12. [mydocker]---一步步实现使用AUFS包装busybox
13. [mydocker]---一步步实现volume操作
14. [mydocker]---实现保存镜像
15. [mydocker]---实现容器的后台运行
16. [mydocker]---实现查看运行中容器
17. [mydocker]---实现查看容器日志
18. [mydocker]---实现进入容器Namespace
19. [mydocker]---实现停止容器
20. [mydocker]---实现删除容器
21. [mydocker]---实现容器层隔离
22. [mydocker]---实现通过容器制作镜像
23. [mydocker]---实现cp操作
24. [mydocker]---实现容器指定环境变量
25. [mydocker]---网际协议IP
26. [mydocker]---网络虚拟设备veth bridge iptables
27. [mydocker]---docker的四种网络模型与原理实现(1)
28. [mydocker]---docker的四种网络模型与原理实现(2)
29. [mydocker]---容器地址分配
30. [mydocker]---网络net/netlink api 使用解析
31. [mydocker]---网络实现
32. [mydocker]---网络实现测试