Overview

The Go SDK provides pre-signed request URLs. For detailed operations, please see the following examples.

Obtaining a pre-signed request URL

go
func (s *ObjectService) GetPresignedURL(ctx context.Context, httpMethod, name, ak, sk string, expired time.Duration, opt interface{}) (*url.URL, error)

Parameter description

Using a permanent key to generate a pre-signed URL

Upload request sample

go
ak := "SECRETID"
sk := "SECRETKEY"
name := "exampleobject"
ctx := context.Background()
f := strings.NewReader("test")
// 1. Upload the object using the standard method.
_, err := client.Object.Put(ctx, name, f, nil)
if err != nil {
   panic(err)
}
// Obtain the pre-signed URL.
presignedURL, err := client.Object.GetPresignedURL(ctx, http.MethodPut, name, ak, sk, time.Hour, nil)
if err != nil {
   panic(err)
}
// 2. Upload the object using a pre-signed URL.
data := "test upload with presignedURL"
f = strings.NewReader(data)
req, err := http.NewRequest(http.MethodPut, presignedURL.String(), f)
if err != nil {
   panic(err)
}
// You can configure request headers by yourself.
req.Header.Set("Content-Type", "text/html")
_, err = http.DefaultClient.Do(req)
if err != nil {
   panic(err)
}

Download request sample

go
ak := "SECRETID"
sk := "SECRETKEY"
name := "exampleobject"
ctx := context.Background()
// 1. Download the object using the standard method.
resp, err := client.Object.Get(ctx, name, nil)
if err != nil {
   panic(err)
}
bs, _ := ioutil.ReadAll(resp.Body)
resp.Body.Close()
// Obtain the pre-signed URL.
presignedURL, err := client.Object.GetPresignedURL(ctx, http.MethodGet, name, ak, sk, time.Hour, nil)
if err != nil {
   panic(err)
}
// 2. Download the object using a pre-signed URL.
resp2, err := http.Get(presignedURL.String())
if err != nil {
   panic(err)
}
bs2, _ := ioutil.ReadAll(resp2.Body)
resp2.Body.Close()
if bytes.Compare(bs2, bs) != 0 {
   panic(errors.New("content is not consistent"))
}

Generating Pre-signed URL with Temporary Key

go
// You can use tags to put the request parameters or request headers in the signature.
type URLToken struct {
SessionToken string `url:"x-cos-security-token,omitempty" header:"-"`
}
func main() {
// Replace it with your temporary key.
tak := os.Getenv("SECRETID")
tsk := os.Getenv("SECRETKEY")
token := &URLToken{
SessionToken: "<token>",
}
u, _ := url.Parse("https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com")
b := &cos.BaseURL{BucketURL: u}
c := cos.NewClient(b, &http.Client{})
name := "exampleobject"
ctx := context.Background()
// Method 1. Use tags to configure “x-cos-security-token”.
// Get presigned
presignedURL, err := c.Object.GetPresignedURL(ctx, http.MethodGet, name, tak, tsk, time.Hour, token)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
// Get object by presigned URL
resp, err := http.Get(presignedURL.String())
if err != nil {
fmt.Printf("Error: %v\n", err)
}
defer resp.Body.Close()
fmt.Println(presignedURL.String())
fmt.Printf("resp:%v\n", resp)
// Method 2. Use “PresignedURLOptions” to configure “x-cos-security-token”.
  // You can add request parameters and request headers through “PresignedURLOptions”.
opt := &cos.PresignedURLOptions{
Query:  &url.Values{},
Header: &http.Header{},
}
opt.Query.Add("x-cos-security-token", "<token>")
// Get presigned
presignedURL, err = c.Object.GetPresignedURL(ctx, http.MethodGet, name, tak, tsk, time.Hour, opt)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
// Get object by presigned URL
resp, err = http.Get(presignedURL.String())
if err != nil {
fmt.Printf("Error: %v\n", err)
}
defer resp.Body.Close()
fmt.Println(presignedURL.String())
fmt.Printf("resp:%v\n", resp)
}