下载对象

背景

用户通过云平台申请的永久aksk，结合开源的minio-go/python SDK将桶中的对象下载到本地

步骤

• 通过云平台创建永久aksk
• 通过开源SDK下载对象

云平台创建永久aksk

参考"获取永久aksk"文档

下载对象

方法一：直接下载对象

利用永久aksk，直接将桶中的对象下载到本地

package main

import (
    "context"
    "io"
    "log"
    "os"

    "github.com/minio/minio-go/v7"
    "github.com/minio/minio-go/v7/pkg/credentials"
)

const (
    AccessKeyID     = "XDZ***********gp2x"
    SecretAccessKey = "iseXX***********************Hm5l"
    obj             = "upload.txt"
    bucket          = "ttt2222"
    storageGateway  = "http://s3.mediacloud.imgo.tv"
)

func main() {
    s3Client, err := minio.New(storageGateway, &minio.Options{
        Creds:  credentials.NewStaticV4(AccessKeyID, SecretAccessKey, ""),
        Secure: true,
    })
    if err != nil {
        log.Fatalln(err)
    }

    reader, err := s3Client.GetObject(context.Background(), bucket, obj, minio.GetObjectOptions{})
    if err != nil {
        log.Fatalln(err)
    }
    defer reader.Close()

    localFile, err := os.Create(obj)
    if err != nil {
        log.Fatalln(err)
    }
    defer localFile.Close()

    stat, err := reader.Stat()
    if err != nil {
        log.Fatalln(err)
    }

    if _, err := io.CopyN(localFile, reader, stat.Size); err != nil {
        log.Fatalln(err)
    }
}

方法二：通过生成下载地址下载对象

• 第一步：生成对象下载地址，需要修改aksk，bucket和obj这四个参数

  package main
  
  import (
      "context"
      "log"
      "net/url"
      "time"
  
      "github.com/minio/minio-go/v7"
      "github.com/minio/minio-go/v7/pkg/credentials"
  )
  
  const (
      AccessKeyID     = "XDZ***********gp2x"
      SecretAccessKey = "iseXX***********************Hm5l"
      obj             = "upload.txt"
      bucket          = "ttt2222"
      storageGateway  = "http://s3.mediacloud.imgo.tv"
  )
  
  func main() {
      s3Client, err := minio.New(storageGateway, &minio.Options{
          Creds:  credentials.NewStaticV4(AccessKeyID, SecretAccessKey, ""),
          Secure: true,
      })
      if err != nil {
          log.Fatalln(err)
      }
  
      // Set request parameters
      reqParams := make(url.Values)
      att := fmt.Sprintf("attachment; filename=\"%s\"", obj)
      reqParams.Set("response-content-disposition", att)
  
      // Gernerate presigned get object url.
      presignedURL, err := s3Client.PresignedGetObject(context.Background(), bucket, obj, time.Duration(1000)*time.Second, reqParams)
      if err != nil {
          log.Fatalln(err)
      }
      log.Println(presignedURL)
  }
  

• 第二步，用第一步生成的下载地址下载对象,url改成第一步返回的结果，obj是需要下载的对象

  package main
  
  import (
      "fmt"
      "io/ioutil"
      "net/http"
      "os"
  )
  
  const (
      url = ""
      obj = "upload.txt"
  )
  
  func main() {
  
      url := ""
      method := "GET"
  
      client := &http.Client{}
      req, err := http.NewRequest(method, url, nil)
  
      if err != nil {
          fmt.Println(err)
          return
      }
      req.Header.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9")
      req.Header.Add("Accept-Language", "zh-CN,zh;q=0.9")
      req.Header.Add("Connection", "keep-alive")
      req.Header.Add("Upgrade-Insecure-Requests", "1")
      req.Header.Add("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36")
  
      res, err := client.Do(req)
      if err != nil {
          fmt.Println(err)
          return
      }
      defer res.Body.Close()
  
      body, err := ioutil.ReadAll(res.Body)
      if err != nil {
          fmt.Println(err)
          return
      }
      // fmt.Println(string(body))
  
      f, err := os.Create(obj)
      if err != nil {
          fmt.Println(err)
          return
      }
      n, err := f.Write(body)
      if err != nil {
          fmt.Println(err)
          return
      }
      fmt.Printf("write %d bytes", n)
  }