Object Storage Service:Charger un object à l'aide d'une URL pré-signée (SDK Python V2)

import argparse
import requests
import alibabacloud_oss_v2 as oss

from datetime import datetime, timedelta

# Create a command-line argument parser and describe the script's purpose: to generate a presigned PUT request URL for an object (Presign Put Object).
parser = argparse.ArgumentParser(description="presign put object sample")

# Define command-line arguments, including the required region, bucket name, endpoint, and object key.
parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
parser.add_argument('--bucket', help='The name of the bucket.', required=True)
parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')
parser.add_argument('--key', help='The name of the object.', required=True)

def main():
    # Parse command-line arguments to get user-provided values.
    args = parser.parse_args()

    # Load access credential information from environment variables for identity verification.
    credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()

    # Create a configuration object using the SDK's default settings and set the authentication provider.
    cfg = oss.config.load_default()
    cfg.credentials_provider = credentials_provider

    # Set the region property of the configuration object based on the command-line arguments.
    cfg.region = args.region

    # If a custom endpoint is provided, update the endpoint property in the configuration object.
    if args.endpoint is not None:
        cfg.endpoint = args.endpoint

    # Initialize the OSS client with the above configuration to interact with OSS.
    client = oss.Client(cfg)

    # Send a request to generate a presigned PUT request for the specified object.
    pre_result = client.presign(oss.PutObjectRequest(
        bucket=args.bucket,  # Bucket name
        key=args.key,  # Object key
        content_type='text/plain;charset=utf8',  # Specify the content type.
        storage_class='Standard',  # Specify the storage class.
        metadata={
            'key1': 'value1',   # Specify the metadata.
            'key2': 'value2'    # Specify the metadata.
        }
    ),expires=timedelta(seconds=3600)) # Set the expiration time in seconds. Here, it is set to 3600 seconds.

    # Print the method, expiration time, and URL of the presigned request to confirm the validity of the link.
    print(f'method: {pre_result.method},'
          f' expiration: {pre_result.expiration.strftime("%Y-%m-%dT%H:%M:%S.000Z")},'
          f' url: {pre_result.url}'
          )

    # Print the signed header information of the presigned request. This information will be included in the HTTP headers when the actual request is sent.
    for key, value in pre_result.signed_headers.items():
        print(f'signed headers key: {key}, signed headers value: {value}')

# When this script is executed directly, call the main function to start the processing logic.
if __name__ == "__main__":
    main()  # Script entry point. The program flow starts here.

Remarques d'utilisation

• Le code exemple de cette rubrique utilise la région Chine (Hangzhou) (cn-hangzhou) à titre d'exemple. Un endpoint public est utilisé par défaut. Si vous accédez à OSS depuis un autre service Alibaba Cloud dans la même région, vous devez utiliser un endpoint interne. Pour plus d'informations sur les régions et les endpoints OSS, consultez Régions et endpoints.

• Aucune autorisation n'est requise pour générer une URL présignée. Toutefois, un tiers ne peut télécharger un fichier avec succès via l'URL présignée que si vous disposez de l'autorisation oss:PutObject. Pour plus d'informations, consultez Accorder une politique d'accès personnalisée à un utilisateur RAM.

• Le code exemple de cette rubrique utilise des URL présignées V4, dont la durée de validité maximale est de 7 jours. Pour plus d'informations, consultez Signature V4 (recommandée).

Processus

Pour télécharger un fichier à l'aide d'une URL signée et de la méthode PUT, suivez la procédure ci-dessous :

Définition de la méthode

Vous pouvez générer une URL présignée qui accorde des autorisations d'accès temporaires aux objects d'un bucket et qui peut être utilisée plusieurs fois avant son expiration.

La méthode presign est définie comme suit :

presign(request: PutObjectRequest, **kwargs) → PresignResult

Paramètres de requête

Valeurs de retour

Les valeurs de retour de PresignResult sont répertoriées ci-dessous :

Pour la définition complète de la méthode presign, consultez presign.

Exemple de code

1. Le propriétaire du fichier génère une URL présignée pour la méthode PUT.

   Important

   Lorsque vous générez une URL présignée pour la méthode PUT, si vous spécifiez des en-têtes de requête, vous devez inclure les mêmes en-têtes dans la requête PUT utilisant l'URL présignée. Dans le cas contraire, la vérification de la signature échoue.

   import argparse
   import requests
   import alibabacloud_oss_v2 as oss
   
   from datetime import datetime, timedelta
   
   # Create a command-line argument parser and describe the script's purpose: to generate a presigned PUT request URL for an object (Presign Put Object).
   parser = argparse.ArgumentParser(description="presign put object sample")
   
   # Define command-line arguments, including the required region, bucket name, endpoint, and object key.
   parser.add_argument('--region', help='The region in which the bucket is located.', required=True)
   parser.add_argument('--bucket', help='The name of the bucket.', required=True)
   parser.add_argument('--endpoint', help='The domain names that other services can use to access OSS')
   parser.add_argument('--key', help='The name of the object.', required=True)
   
   def main():
       # Parse command-line arguments to get user-provided values.
       args = parser.parse_args()
   
       # Load access credential information from environment variables for identity verification.
       credentials_provider = oss.credentials.EnvironmentVariableCredentialsProvider()
   
       # Create a configuration object using the SDK's default settings and set the authentication provider.
       cfg = oss.config.load_default()
       cfg.credentials_provider = credentials_provider
   
       # Set the region property of the configuration object based on the command-line arguments.
       cfg.region = args.region
   
       # If a custom endpoint is provided, update the endpoint property in the configuration object.
       if args.endpoint is not None:
           cfg.endpoint = args.endpoint
   
       # Initialize the OSS client with the above configuration to interact with OSS.
       client = oss.Client(cfg)
   
       # Send a request to generate a presigned PUT request for the specified object.
       pre_result = client.presign(oss.PutObjectRequest(
           bucket=args.bucket,  # Bucket name
           key=args.key,  # Object key
       ),expires=timedelta(seconds=3600)) # Set the expiration time in seconds. Here, it is set to 3600 seconds.
   
       # Print the method, expiration time, and URL of the presigned request to confirm the validity of the link.
       print(f'method: {pre_result.method},'
             f' expiration: {pre_result.expiration.strftime("%Y-%m-%dT%H:%M:%S.000Z")},'
             f' url: {pre_result.url}'
             )
   
       # Print the signed header information of the presigned request. This information will be included in the HTTP headers when the actual request is sent.
       for key, value in pre_result.signed_headers.items():
           print(f'signed headers key: {key}, signed headers value: {value}')
   
   # When this script is executed directly, call the main function to start the processing logic.
   if __name__ == "__main__":
       main()  # Script entry point. The program flow starts here.

2. Un autre utilisateur télécharge un fichier à l'aide de l'URL présignée pour la méthode PUT.

   curl

   curl -X PUT -T /path/to/local/file "https://exampleobject.oss-cn-hangzhou.aliyuncs.com/exampleobject.txt?x-oss-date=20241112T083238Z&x-oss-expires=3599&x-oss-signature-version=OSS4-HMAC-SHA256&x-oss-credential=LTAI****************%2F20241112%2Fcn-hangzhou%2Foss%2Faliyun_v4_request&x-oss-signature=ed5a******************************************************"

   Java

   import org.apache.http.HttpEntity;
   import org.apache.http.client.methods.CloseableHttpResponse;
   import org.apache.http.client.methods.HttpPut;
   import org.apache.http.entity.FileEntity;
   import org.apache.http.impl.client.CloseableHttpClient;
   import org.apache.http.impl.client.HttpClients;
   import java.io.*;
   import java.net.URL;
   import java.util.*;
   
   public class SignUrlUpload {
       public static void main(String[] args) throws Throwable {
           CloseableHttpClient httpClient = null;
           CloseableHttpResponse response = null;
   
           // Replace <signedUrl> with the authorized URL.
           URL signedUrl = new URL("<signedUrl>");
   
           // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
           String pathName = "C:\\Users\\demo.txt";
   
           try {
               HttpPut put = new HttpPut(signedUrl.toString());
               System.out.println(put);
               HttpEntity entity = new FileEntity(new File(pathName));
               put.setEntity(entity);
               httpClient = HttpClients.createDefault();
               response = httpClient.execute(put);
   
               System.out.println("Status code returned for the upload:"+response.getStatusLine().getStatusCode());
               if(response.getStatusLine().getStatusCode() == 200){
                   System.out.println("Upload successful using network library.");
               }
               System.out.println(response.toString());
           } catch (Exception e){
               e.printStackTrace();
           } finally {
                if (response != null) {
                    response.close();
                }
                if (httpClient != null) {
                    httpClient.close();
                }
            }
       }
   }       

   Go

   package main
   
   import (
   	"fmt"
   	"io"
   	"net/http"
   	"os"
   )
   
   func uploadFile(signedUrl, filePath string) error {
   	// Open the file.
   	file, err := os.Open(filePath)
   	if err != nil {
   		return fmt.Errorf("Unable to open file: %w", err)
   	}
   	defer file.Close()
   
   	// Create a new HTTP client.
   	client := &http.Client{}
   
   	// Create a PUT request.
   	req, err := http.NewRequest("PUT", signedUrl, file)
   	if err != nil {
   		return fmt.Errorf("Failed to create request: %w", err)
   	}
   
   	// Send the request.
   	resp, err := client.Do(req)
   	if err != nil {
   		return fmt.Errorf("Failed to send request: %w", err)
   	}
   	defer resp.Body.Close()
   
   	// Read the response.
   	body, err := io.ReadAll(resp.Body)
   	if err != nil {
   		return fmt.Errorf("Failed to read response: %w", err)
   	}
   
   	fmt.Printf("Status code returned for the upload: %d\n", resp.StatusCode)
   	if resp.StatusCode == 200 {
   		fmt.Println("Upload successful using network library.")
   	}
   	fmt.Println(string(body))
   
   	return nil
   }
   
   func main() {
   	// Replace <signedUrl> with the authorized URL.
   	signedUrl := "<signedUrl>"
   
   	// Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
   	filePath := "C:\\Users\\demo.txt"
   
   	err := uploadFile(signedUrl, filePath)
   	if err != nil {
   		fmt.Println("An error occurred:", err)
   	}
   }
   

   python

   import requests
   
   def upload_file(signed_url, file_path):
       try:
           # Open the file.
           with open(file_path, 'rb') as file:
               # Send a PUT request to upload the file.
               response = requests.put(signed_url, data=file)
        
           print(f"Status code returned for the upload: {response.status_code}")
           if response.status_code == 200:
               print("Upload successful using network library.")
           print(response.text)
    
       except Exception as e:
           print(f"An error occurred: {e}")
   
   if __name__ == "__main__":
       # Replace <signedUrl> with the authorized URL.
       signed_url = "<signedUrl>"
       
       # Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
       file_path = "C:\\Users\\demo.txt"
   
       upload_file(signed_url, file_path)
   

   Node.js

   Important

   Si vous rencontrez une erreur de non-correspondance de signature 403 lors du téléchargement d'un fichier avec Node.js, cela est généralement dû au fait que l'en-tête de requête Content-Type est explicitement défini dans la requête de téléchargement, mais qu'il n'a pas été inclus lors de la génération de l'URL présignée. Cette incompatibilité entraîne un échec de la vérification de la signature. Pour résoudre ce problème, ne définissez pas l'en-tête de requête Content-Type dans la requête de téléchargement ou spécifiez l'en-tête de requête Content-Type lors de la génération de l'URL présignée.

   const fs = require('fs');
   const axios = require('axios');
   
   async function uploadFile(signedUrl, filePath) {
       try {
           // Create a read stream.
           const fileStream = fs.createReadStream(filePath);
   
           // Send a PUT request to upload the file.
           const response = await axios.put(signedUrl, fileStream);
   
           console.log(`Status code returned for the upload: ${response.status}`);
           if (response.status === 200) {
               console.log('Upload successful using network library.');
           }
           console.log(response.data);
       } catch (error) {
           console.error(`An error occurred: ${error.message}`);
       }
   }
   
   // Main function.
   (async () => {
       // Replace <signedUrl> with the authorized URL.
       const signedUrl = '<signedUrl>';
       
       // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
       const filePath = 'C:\\Users\\demo.txt';
   
       await uploadFile(signedUrl, filePath);
   })();

   browser.js

   Important

   Si vous rencontrez une erreur de non-correspondance de signature 403 lors du téléchargement d'un fichier avec Browser.js, cela est généralement dû au fait que le navigateur ajoute automatiquement l'en-tête de requête Content-Type et que cet en-tête n'a pas été inclus lors de la génération de l'URL présignée. Cette incompatibilité entraîne un échec de la vérification de la signature. Pour résoudre ce problème, vous devez spécifier l'en-tête de requête Content-Type lors de la génération de l'URL présignée.

   <!DOCTYPE html>
   <html lang="en">
   <head>
       <meta charset="UTF-8">
       <meta name="viewport" content="width=device-width, initial-scale=1.0">
       <title>File Upload Example</title>
   </head>
   <body>
       <h1>File Upload Example</h1>
   
       <!-- Select a file -->
       <input type="file" id="fileInput" />
       <button id="uploadButton">Upload File</button>
   
       <script>
           // Replace this with the presigned URL generated in Step 1.
           const signedUrl = "<signedUrl>"; 
   
           document.getElementById('uploadButton').addEventListener('click', async () => {
               const fileInput = document.getElementById('fileInput');
               const file = fileInput.files[0];
   
               if (!file) {
                   alert('Please select a file to upload.');
                   return;
               }
   
               try {
                   await upload(file, signedUrl);
                   alert('File uploaded successfully!');
               } catch (error) {
                   console.error('Error during upload:', error);
                   alert('Upload failed: ' + error.message);
               }
           });
   
           /**
            * Upload the file to OSS.
            * @param {File} file - The file to upload.
            * @param {string} presignedUrl - The presigned URL.
            */
           const upload = async (file, presignedUrl) => {
               const response = await fetch(presignedUrl, {
                   method: 'PUT',
                   body: file,  // Upload the entire file directly.
               });
   
               if (!response.ok) {
                   throw new Error(`Upload failed, status: ${response.status}`);
               }
   
               console.log('File uploaded successfully');
           };
       </script>
   </body>
   </html>

   C#

   using System.Net.Http.Headers;
   
   // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
   var filePath = "C:\\Users\\demo.txt";
   // Replace <signedUrl> with the authorized URL.
   var presignedUrl = "<signedUrl>";
   
   // Create an HTTP client and open the local file stream.
   using var httpClient = new HttpClient(); 
   using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
   using var content = new StreamContent(fileStream);
               
   // Create a PUT request.
   var request = new HttpRequestMessage(HttpMethod.Put, presignedUrl);
   request.Content = content;
   
   // Send the request.
   var response = await httpClient.SendAsync(request);
   
   // Process the response.
   if (response.IsSuccessStatusCode)
   {
       Console.WriteLine($"Upload successful! Status code: {response.StatusCode}");
       Console.WriteLine("Response headers:");
       foreach (var header in response.Headers)
       {
           Console.WriteLine($"{header.Key}: {string.Join(", ", header.Value)}");
       }
   }
   else
   {
       string responseContent = await response.Content.ReadAsStringAsync();
       Console.WriteLine($"Upload failed! Status code: {response.StatusCode}");
       Console.WriteLine("Response content: " + responseContent);
   }

   C++

   #include <iostream>
   #include <fstream>
   #include <curl/curl.h>
   
   void uploadFile(const std::string& signedUrl, const std::string& filePath) {
       CURL *curl;
       CURLcode res;
   
       curl_global_init(CURL_GLOBAL_DEFAULT);
       curl = curl_easy_init();
   
       if (curl) {
           // Set the URL.
           curl_easy_setopt(curl, CURLOPT_URL, signedUrl.c_str());
   
           // Set the request method to PUT.
           curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
   
           // Open the file.
           FILE *file = fopen(filePath.c_str(), "rb");
           if (!file) {
               std::cerr << "Unable to open file: " << filePath << std::endl;
               return;
           }
   
           // Get the file size.
           fseek(file, 0, SEEK_END);
           long fileSize = ftell(file);
           fseek(file, 0, SEEK_SET);
   
           // Set the file size.
           curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fileSize);
   
           // Set the input file handle.
           curl_easy_setopt(curl, CURLOPT_READDATA, file);
   
           // Execute the request.
           res = curl_easy_perform(curl);
   
           if (res != CURLE_OK) {
               std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << std::endl;
           } else {
               long httpCode = 0;
               curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpCode);
               std::cout << "Status code returned for the upload: " << httpCode << std::endl;
   
               if (httpCode == 200) {
                   std::cout << "Upload successful using network library." << std::endl;
               }
           }
   
           // Close the file.
           fclose(file);
   
           // Clean up.
           curl_easy_cleanup(curl);
       }
   
       curl_global_cleanup();
   }
   
   int main() {
       // Replace <signedUrl> with the authorized URL.
       std::string signedUrl = "<signedUrl>";
   
       // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
       std::string filePath = "C:\\Users\\demo.txt";
   
       uploadFile(signedUrl, filePath);
   
       return 0;
   }
   

   Android

   package com.example.signurlupload;
   
   import android.os.AsyncTask;
   import android.util.Log;
   
   import java.io.DataOutputStream;
   import java.io.FileInputStream;
   import java.io.IOException;
   import java.net.HttpURLConnection;
   import java.net.URL;
   
   public class SignUrlUploadActivity {
   
       private static final String TAG = "SignUrlUploadActivity";
   
       public void uploadFile(String signedUrl, String filePath) {
           new UploadTask().execute(signedUrl, filePath);
       }
   
       private class UploadTask extends AsyncTask<String, Void, String> {
   
           @Override
           protected String doInBackground(String... params) {
               String signedUrl = params[0];
               String filePath = params[1];
   
               HttpURLConnection connection = null;
               DataOutputStream dos = null;
               FileInputStream fis = null;
   
               try {
                   URL url = new URL(signedUrl);
                   connection = (HttpURLConnection) url.openConnection();
                   connection.setRequestMethod("PUT");
                   connection.setDoOutput(true);
                   connection.setRequestProperty("Content-Type", "application/octet-stream");
   
                   fis = new FileInputStream(filePath);
                   dos = new DataOutputStream(connection.getOutputStream());
   
                   byte[] buffer = new byte[1024];
                   int length;
   
                   while ((length = fis.read(buffer)) != -1) {
                       dos.write(buffer, 0, length);
                   }
   
                   dos.flush();
                   dos.close();
                   fis.close();
   
                   int responseCode = connection.getResponseCode();
                   Log.d(TAG, "Status code returned for the upload: " + responseCode);
   
                   if (responseCode == 200) {
                       Log.d(TAG, "Upload successful using network library.");
                   }
   
                   return "Upload complete. Status code: " + responseCode;
   
               } catch (IOException e) {
                   e.printStackTrace();
                   return "Upload failed: " + e.getMessage();
               } finally {
                   if (connection != null) {
                       connection.disconnect();
                   }
               }
           }
   
           @Override
           protected void onPostExecute(String result) {
               Log.d(TAG, result);
           }
       }
   
       public static void main(String[] args) {
           SignUrlUploadActivity activity = new SignUrlUploadActivity();
           // Replace <signedUrl> with the authorized URL.
           String signedUrl = "<signedUrl>";
           // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
           String filePath = "C:\\Users\\demo.txt";
           activity.uploadFile(signedUrl, filePath);
       }
   }
   

FAQ

Références

• Pour le code exemple complet relatif au téléchargement d'un fichier à l'aide d'une URL présignée, consultez presigner_put_object.py.

• Pour le code exemple complet relatif à l'exécution d'un téléchargement multipartie à l'aide d'une URL présignée, consultez presigner_complete_multipart_upload.py.