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与用户交互的交互式容器中,通过 Golang docker SDK 启用 os.stdin 接收用户输入

来源:stackoverflow

时间:2024-03-22 13:36:59 466浏览 收藏

在使用 Golang Docker SDK 与容器交互时,通过启用 `os.stdin` 接收用户输入至关重要。本文介绍了如何使用 `docker/docker` 库中的 `client.containerattach` 函数来实现这一目标。该解决方案涉及创建会话流,通过该流容器可以与用户交互,等待用户输入并将其发送到容器。通过遵循提供的代码示例,开发人员可以实现交互式容器,允许用户在运行时提供输入。

问题内容

我的最后一招是在这里问。我是 golang 新手,我编写了一些简单的程序。

我正在尝试执行以下操作: 使用戈兰: 1 - 运行容器 2 - 接受容器的输入标准输入

我想使用的示例是 hashicorp/terraform docker 映像,我想做一个简单的 terraform apply 但我需要等待用户输入

下面是我到目前为止正在工作的代码...任何尝试下面确切代码的人都需要更新 aws 环境变量或将 terraform 测试文件更改为另一个提供商...或者只是使用不同的 docker 映像;-)

package main

import (
    "fmt"
    "github.com/docker/docker/api/types"
    "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/api/types/mount"
    "github.com/docker/docker/client"
    "github.com/docker/docker/pkg/stdcopy"
    "golang.org/x/net/context"
    "io"
    "os"
)

const workingdir = "/home"


func main() {
    ctx := context.background()
    cli, err := client.newclientwithopts(client.fromenv, client.withapiversionnegotiation())
    if err != nil {
        panic(err)
    }

    reader, err := cli.imagepull(ctx, "hashicorp/terraform", types.imagepulloptions{})
    if err != nil {
        panic(err)
    }
    io.copy(os.stdout, reader)

    fmt.println(os.args)
    cwd, _ := os.getwd()

    resp, err := cli.containercreate(ctx, &container.config{
        attachstdin: true,
        tty:         false,
        stdinonce:   true,
        attachstdout:true,
        cmd:         os.args[1:],
        image:       "hashicorp/terraform",
        workingdir:   workingdir,
        env:         []string{"aws_access_key_id=xxx", "aws_secret_access_key=xxx", "aws_session_token=xxx"},
        },
    &container.hostconfig{

            mounts: []mount.mount{
                mount.mount{
                    type: mount.typebind,
                    source: cwd,
                    target: workingdir,
                },
            },
        },nil, "")
    if err != nil {
        panic(err)
    }

    if err := cli.containerstart(ctx, resp.id, types.containerstartoptions{}); err != nil {
        panic(err)
    }

    statusch, errch := cli.containerwait(ctx, resp.id, container.waitconditionnotrunning)
    select {
    case err := <-errch:
        if err != nil {
            panic(err)
        }
    case <-statusch:
    }




    out, err := cli.containerlogs(ctx, resp.id, types.containerlogsoptions{showstdout: true})
    if err != nil {
        panic(err)
    }

    stdcopy.stdcopy(os.stdout, os.stderr, out)


}

我的示例 terraform 文件 test.tf

provider "aws" {
  region                  = "eu-west-1"
}


resource "aws_vpc" "main" {
  cidr_block       = "10.0.0.0/16"
  instance_tenancy = "dedicated"

  tags = {
    name = "test-main-vpc"
  }
}

所以如果我构建该 go 文件并运行类似的内容

./build apply 与 test.tf 位于同一目录

我得到以下输出:

an execution plan has been generated and is shown below.
resource actions are indicated with the following symbols:
  + create

terraform will perform the following actions:

  # aws_vpc.main will be created
  + resource "aws_vpc" "main" {
      + arn                              = (known after apply)
      + assign_generated_ipv6_cidr_block = false
      + cidr_block                       = "10.0.0.0/16"
      + default_network_acl_id           = (known after apply)
      + default_route_table_id           = (known after apply)
      + default_security_group_id        = (known after apply)
      + dhcp_options_id                  = (known after apply)
      + enable_classiclink               = (known after apply)
      + enable_classiclink_dns_support   = (known after apply)
      + enable_dns_hostnames             = (known after apply)
      + enable_dns_support               = true
      + id                               = (known after apply)
      + instance_tenancy                 = "dedicated"
      + ipv6_association_id              = (known after apply)
      + ipv6_cidr_block                  = (known after apply)
      + main_route_table_id              = (known after apply)
      + owner_id                         = (known after apply)
      + tags                             = {
          + "name" = "test-main-vpc"
        }
    }

plan: 1 to add, 0 to change, 0 to destroy.

do you want to perform these actions?
  terraform will perform the actions described above.
  only 'yes' will be accepted to approve.

  enter a value: 
apply cancelled.

process finished with exit code 0

我一直试图弄清楚如何等待用户输入。

日志是在容器运行并退出后打印的,我认为..所以我相信我需要混合使用这些:

https://godoc.org/github.com/docker/docker/container/stream

https://godoc.org/github.com/docker/docker/client#client.containerattach

我只是不知道如何实现这些,也没有例子。

任何想法都会有帮助。我不需要完整的答案,我只想要有关如何使用容器/流和/或 client.containerattach 等待用户输入的一般方向

非常感谢!

编辑:

我已经成功让它工作了。下面是工作代码

package main

import (
    "bufio"
    "fmt"
    "github.com/docker/docker/api/types"
    "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/api/types/mount"
    "github.com/docker/docker/client"
    "golang.org/x/net/context"
    "io"
    "os"
)

const workingDir = "/home"
var inout chan []byte

func main() {
    inout = make(chan []byte)

    ctx := context.Background()
    cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
    if err != nil {
        panic(err)
    }

    reader, err := cli.ImagePull(ctx, "hashicorp/terraform", types.ImagePullOptions{})
    if err != nil {
        panic(err)
    }
    go io.Copy(os.Stdout, reader)


    //fmt.Println(os.Args)
    cwd, _ := os.Getwd()

    resp, err := cli.ContainerCreate(ctx, &container.Config{
        AttachStderr:true,
        AttachStdin: true,
        Tty:         true,
        AttachStdout:true,
        OpenStdin:   true,
        Cmd:         os.Args[1:],
        Image:       "hashicorp/terraform",
        WorkingDir:   workingDir,
        Env:         []string{"AWS_ACCESS_KEY_ID=",
            "AWS_SECRET_ACCESS_KEY=",
            "AWS_SESSION_TOKEN=",

        },
    },
        &container.HostConfig{

            Mounts: []mount.Mount{
                mount.Mount{
                    Type: mount.TypeBind,
                    Source: cwd,
                    Target: workingDir,
                },
            },
        },nil, "")
    if err != nil {
        panic(err)
    }


    if err := cli.ContainerStart(ctx, resp.ID, types.ContainerStartOptions{}); err != nil {
        panic(err)
    }



    waiter, err := cli.ContainerAttach(ctx, resp.ID, types.ContainerAttachOptions{
        Stderr:       true,
        Stdout:       true,
        Stdin:        true,
        Stream:       true,
    })

    go  io.Copy(os.Stdout, waiter.Reader)
    go  io.Copy(os.Stderr, waiter.Reader)

    if err != nil {
        panic(err)
    }

    go func() {
        scanner := bufio.NewScanner(os.Stdin)
        for scanner.Scan() {
            inout <- []byte(scanner.Text())
        }
    }()

    // Write to docker container
    go func(w io.WriteCloser) {
        for {
            data, ok := <-inout
            //log.Println("Received to send to docker", string(data))
            if !ok {
                fmt.Println("!ok")
                w.Close()
                return
            }

            w.Write(append(data, '\n'))
        }
    }(waiter.Conn)


    statusCh, errCh := cli.ContainerWait(ctx, resp.ID, container.WaitConditionNotRunning)
    select {
    case err := <-errCh:
        if err != nil {
            panic(err)
        }
    case <-statusCh:
    }


}

解决方案


对您的问题的编辑非常有帮助,所以我只想更新对我有用的内容。

我在使用您的 stdin 解决方案(与 scanner 和 waiter.conn 相关)时遇到问题,并采纳了 nierobot 的建议来使用 docker 的 cli 源代码中使用的 io.copy。

为了获得终端的感觉(从 stdin、自动完成等中删除回显),我引用了这个线程:https://github.com/fsouza/go-dockerclient/issues/707,它基本上说你必须将 stdin 视为原始终端(后来意识到这也是在 docker 的 cli 源代码中完成的) )。同样重要的是要注意,您必须尽快恢复终端状态,否则您的其他打印语句可能会不稳定。

最后,我的最终代码看起来像这样......

// ContainerCreate
    
// ContainerAttach

go io.Copy(os.Stdout, waiter.Reader)
go io.Copy(os.Stderr, waiter.Reader)
go io.Copy(waiter.Conn, os.Stdin)

// ContainerStart

// import("golang.org/x/net/context")
fd := int(os.Stdin.Fd())
var oldState *terminal.State
if terminal.IsTerminal(fd) {
  oldState, err = terminal.MakeRaw(fd)
  if err != nil {
    // print error
  }
  defer terminal.Restore(fd, oldState)
}

// ContainerWait for exit

terminal.Restore(fd, oldState)

以上就是本文的全部内容了,是否有顺利帮助你解决问题?若是能给你带来学习上的帮助,请大家多多支持golang学习网!更多关于Golang的相关知识,也可关注golang学习网公众号。

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