使用 Amazon SDK 创建 Amazon S3 的预签名 URL

生成可在有限时间内执行 Amazon S3 操作的预签名 URL。

    using System;
    using Amazon;
    using Amazon.S3;
    using Amazon.S3.Model;

    public class GenPresignedUrl
    {
        public static void Main()
        {
            const string bucketName = "doc-example-bucket";
            const string objectKey = "sample.txt";

            // Specify how long the presigned URL lasts, in hours
            const double timeoutDuration = 12;

            // Specify the AWS Region of your Amazon S3 bucket. If it is
            // different from the Region defined for the default user,
            // pass the Region to the constructor for the client. For
            // example: new AmazonS3Client(RegionEndpoint.USEast1);

            // If using the Region us-east-1, and server-side encryption with AWS KMS, you must specify Signature Version 4.
            // Region us-east-1 defaults to Signature Version 2 unless explicitly set to Version 4 as shown below.
            // For more details, see https://docs.aws.amazon.com/AmazonS3/latest/userguide/UsingAWSSDK.html#specify-signature-version
            // and https://docs.aws.amazon.com/sdkfornet/v3/apidocs/items/Amazon/TAWSConfigsS3.html
            AWSConfigsS3.UseSignatureVersion4 = true;
            IAmazonS3 s3Client = new AmazonS3Client(RegionEndpoint.USEast1);

            string urlString = GeneratePresignedURL(s3Client, bucketName, objectKey, timeoutDuration);
            Console.WriteLine($"The generated URL is: {urlString}.");
        }

        /// <summary>
        /// Generate a presigned URL that can be used to access the file named
        /// in the objectKey parameter for the amount of time specified in the
        /// duration parameter.
        /// </summary>
        /// <param name="client">An initialized S3 client object used to call
        /// the GetPresignedUrl method.</param>
        /// <param name="bucketName">The name of the S3 bucket containing the
        /// object for which to create the presigned URL.</param>
        /// <param name="objectKey">The name of the object to access with the
        /// presigned URL.</param>
        /// <param name="duration">The length of time for which the presigned
        /// URL will be valid.</param>
        /// <returns>A string representing the generated presigned URL.</returns>
        public static string GeneratePresignedURL(IAmazonS3 client, string bucketName, string objectKey, double duration)
        {
            string urlString = string.Empty;
            try
            {
                var request = new GetPreSignedUrlRequest()
                {
                    BucketName = bucketName,
                    Key = objectKey,
                    Expires = DateTime.UtcNow.AddHours(duration),
                };
                urlString = client.GetPreSignedURL(request);
            }
            catch (AmazonS3Exception ex)
            {
                Console.WriteLine($"Error:'{ex.Message}'");
            }

            return urlString;
        }
    }

生成预签名 URL 并使用该 URL 执行上载。

    using System;
    using System.IO;
    using System.Net;
    using Amazon;
    using Amazon.S3;
    using Amazon.S3.Model;

    public class UploadUsingPresignedURL
    {
        public static void Main()
        {
            string bucketName = "doc-example-bucket";
            string keyName = "samplefile.txt";
            string filePath = $"source\\{keyName}";

            // Specify how long the signed URL will be valid in hours.
            double timeoutDuration = 12;

            // Specify the AWS Region of your Amazon S3 bucket. If it is
            // different from the Region defined for the default user,
            // pass the Region to the constructor for the client. For
            // example: new AmazonS3Client(RegionEndpoint.USEast1);

            // If using the Region us-east-1, and server-side encryption with AWS KMS, you must specify Signature Version 4.
            // Region us-east-1 defaults to Signature Version 2 unless explicitly set to Version 4 as shown below.
            // For more details, see https://docs.aws.amazon.com/AmazonS3/latest/userguide/UsingAWSSDK.html#specify-signature-version
            // and https://docs.aws.amazon.com/sdkfornet/v3/apidocs/items/Amazon/TAWSConfigsS3.html
            AWSConfigsS3.UseSignatureVersion4 = true;
            IAmazonS3 client = new AmazonS3Client(RegionEndpoint.USEast1);

            var url = GeneratePreSignedURL(client, bucketName, keyName, timeoutDuration);
            var success = UploadObject(filePath, url);

            if (success)
            {
                Console.WriteLine("Upload succeeded.");
            }
            else
            {
                Console.WriteLine("Upload failed.");
            }
        }

        /// <summary>
        /// Uploads an object to an Amazon S3 bucket using the presigned URL passed in
        /// the url parameter.
        /// </summary>
        /// <param name="filePath">The path (including file name) to the local
        /// file you want to upload.</param>
        /// <param name="url">The presigned URL that will be used to upload the
        /// file to the Amazon S3 bucket.</param>
        /// <returns>A Boolean value indicating the success or failure of the
        /// operation, based on the HttpWebResponse.</returns>
        public static bool UploadObject(string filePath, string url)
        {
            HttpWebRequest httpRequest = WebRequest.Create(url) as HttpWebRequest;
            httpRequest.Method = "PUT";
            using (Stream dataStream = httpRequest.GetRequestStream())
            {
                var buffer = new byte[8000];
                using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
                {
                    int bytesRead = 0;
                    while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        dataStream.Write(buffer, 0, bytesRead);
                    }
                }
            }

            HttpWebResponse response = httpRequest.GetResponse() as HttpWebResponse;
            return response.StatusCode == HttpStatusCode.OK;
        }

        /// <summary>
        /// Generates a presigned URL which will be used to upload an object to
        /// an Amazon S3 bucket.
        /// </summary>
        /// <param name="client">The initialized Amazon S3 client object used to call
        /// GetPreSignedURL.</param>
        /// <param name="bucketName">The name of the Amazon S3 bucket to which the
        /// presigned URL will point.</param>
        /// <param name="objectKey">The name of the file that will be uploaded.</param>
        /// <param name="duration">How long (in hours) the presigned URL will
        /// be valid.</param>
        /// <returns>The generated URL.</returns>
        public static string GeneratePreSignedURL(
            IAmazonS3 client,
            string bucketName,
            string objectKey,
            double duration)
        {
            var request = new GetPreSignedUrlRequest
            {
                BucketName = bucketName,
                Key = objectKey,
                Verb = HttpVerb.PUT,
                Expires = DateTime.UtcNow.AddHours(duration),
            };

            string url = client.GetPreSignedURL(request);
            return url;
        }
    }

创建包装 S3 预签名操作的函数。

// Presigner encapsulates the Amazon Simple Storage Service (Amazon S3) presign actions
// used in the examples.
// It contains PresignClient, a client that is used to presign requests to Amazon S3.
// Presigned requests contain temporary credentials and can be made from any HTTP client.
type Presigner struct {
	PresignClient *s3.PresignClient
}



// GetObject makes a presigned request that can be used to get an object from a bucket.
// The presigned request is valid for the specified number of seconds.
func (presigner Presigner) GetObject(
	bucketName string, objectKey string, lifetimeSecs int64) (*v4.PresignedHTTPRequest, error) {
	request, err := presigner.PresignClient.PresignGetObject(context.TODO(), &s3.GetObjectInput{
		Bucket: aws.String(bucketName),
		Key:    aws.String(objectKey),
	}, func(opts *s3.PresignOptions) {
		opts.Expires = time.Duration(lifetimeSecs * int64(time.Second))
	})
	if err != nil {
		log.Printf("Couldn't get a presigned request to get %v:%v. Here's why: %v\n",
			bucketName, objectKey, err)
	}
	return request, err
}



// PutObject makes a presigned request that can be used to put an object in a bucket.
// The presigned request is valid for the specified number of seconds.
func (presigner Presigner) PutObject(
	bucketName string, objectKey string, lifetimeSecs int64) (*v4.PresignedHTTPRequest, error) {
	request, err := presigner.PresignClient.PresignPutObject(context.TODO(), &s3.PutObjectInput{
		Bucket: aws.String(bucketName),
		Key:    aws.String(objectKey),
	}, func(opts *s3.PresignOptions) {
		opts.Expires = time.Duration(lifetimeSecs * int64(time.Second))
	})
	if err != nil {
		log.Printf("Couldn't get a presigned request to put %v:%v. Here's why: %v\n",
			bucketName, objectKey, err)
	}
	return request, err
}



// DeleteObject makes a presigned request that can be used to delete an object from a bucket.
func (presigner Presigner) DeleteObject(bucketName string, objectKey string) (*v4.PresignedHTTPRequest, error) {
	request, err := presigner.PresignClient.PresignDeleteObject(context.TODO(), &s3.DeleteObjectInput{
		Bucket: aws.String(bucketName),
		Key:    aws.String(objectKey),
	})
	if err != nil {
		log.Printf("Couldn't get a presigned request to delete object %v. Here's why: %v\n", objectKey, err)
	}
	return request, err
}

运行一个交互式示例，以生成并使用预签名 URL 上载、下载和删除 S3 对象。

// RunPresigningScenario is an interactive example that shows you how to get presigned
// HTTP requests that you can use to move data into and out of Amazon Simple Storage
// Service (Amazon S3). The presigned requests contain temporary credentials and can
// be used by an HTTP client.
//
// 1. Get a presigned request to put an object in a bucket.
// 2. Use the net/http package to use the presigned request to upload a local file to the bucket.
// 3. Get a presigned request to get an object from a bucket.
// 4. Use the net/http package to use the presigned request to download the object to a local file.
// 5. Get a presigned request to delete an object from a bucket.
// 6. Use the net/http package to use the presigned request to delete the object.
//
// This example creates an Amazon S3 presign client from the specified sdkConfig so that
// you can replace it with a mocked or stubbed config for unit testing.
//
// It uses a questioner from the `demotools` package to get input during the example.
// This package can be found in the ..\..\demotools folder of this repo.
//
// It uses an IHttpRequester interface to abstract HTTP requests so they can be mocked
// during testing.
func RunPresigningScenario(sdkConfig aws.Config, questioner demotools.IQuestioner, httpRequester IHttpRequester) {
	defer func() {
		if r := recover(); r != nil {
			fmt.Printf("Something went wrong with the demo.")
		}
	}()

	log.Println(strings.Repeat("-", 88))
	log.Println("Welcome to the Amazon S3 presigning demo.")
	log.Println(strings.Repeat("-", 88))

	s3Client := s3.NewFromConfig(sdkConfig)
	bucketBasics := actions.BucketBasics{S3Client: s3Client}
	presignClient := s3.NewPresignClient(s3Client)
	presigner := actions.Presigner{PresignClient: presignClient}

	bucketName := questioner.Ask("We'll need a bucket. Enter a name for a bucket "+
		"you own or one you want to create:", demotools.NotEmpty{})
	bucketExists, err := bucketBasics.BucketExists(bucketName)
	if err != nil {
		panic(err)
	}
	if !bucketExists {
		err = bucketBasics.CreateBucket(bucketName, sdkConfig.Region)
		if err != nil {
			panic(err)
		} else {
			log.Println("Bucket created.")
		}
	}
	log.Println(strings.Repeat("-", 88))

	log.Printf("Let's presign a request to upload a file to your bucket.")
	uploadFilename := questioner.Ask("Enter the path to a file you want to upload:",
		demotools.NotEmpty{})
	uploadKey := questioner.Ask("What would you like to name the uploaded object?",
		demotools.NotEmpty{})
	uploadFile, err := os.Open(uploadFilename)
	if err != nil {
		panic(err)
	}
	defer uploadFile.Close()
	presignedPutRequest, err := presigner.PutObject(bucketName, uploadKey, 60)
	if err != nil {
		panic(err)
	}
	log.Printf("Got a presigned %v request to URL:\n\t%v\n", presignedPutRequest.Method,
		presignedPutRequest.URL)
	log.Println("Using net/http to send the request...")
	info, err := uploadFile.Stat()
	if err != nil {
		panic(err)
	}
	putResponse, err := httpRequester.Put(presignedPutRequest.URL, info.Size(), uploadFile)
	if err != nil {
		panic(err)
	}
	log.Printf("%v object %v with presigned URL returned %v.", presignedPutRequest.Method,
		uploadKey, putResponse.StatusCode)
	log.Println(strings.Repeat("-", 88))

	log.Printf("Let's presign a request to download the object.")
	questioner.Ask("Press Enter when you're ready.")
	presignedGetRequest, err := presigner.GetObject(bucketName, uploadKey, 60)
	if err != nil {
		panic(err)
	}
	log.Printf("Got a presigned %v request to URL:\n\t%v\n", presignedGetRequest.Method,
		presignedGetRequest.URL)
	log.Println("Using net/http to send the request...")
	getResponse, err := httpRequester.Get(presignedGetRequest.URL)
	if err != nil {
		panic(err)
	}
	log.Printf("%v object %v with presigned URL returned %v.", presignedGetRequest.Method,
		uploadKey, getResponse.StatusCode)
	defer getResponse.Body.Close()
	downloadBody, err := io.ReadAll(getResponse.Body)
	if err != nil {
		panic(err)
	}
	log.Printf("Downloaded %v bytes. Here are the first 100 of them:\n", len(downloadBody))
	log.Println(strings.Repeat("-", 88))
	log.Println(string(downloadBody[:100]))
	log.Println(strings.Repeat("-", 88))

	log.Println("Let's presign a request to delete the object.")
	questioner.Ask("Press Enter when you're ready.")
	presignedDelRequest, err := presigner.DeleteObject(bucketName, uploadKey)
	if err != nil {
		panic(err)
	}
	log.Printf("Got a presigned %v request to URL:\n\t%v\n", presignedDelRequest.Method,
		presignedDelRequest.URL)
	log.Println("Using net/http to send the request...")
	delResponse, err := httpRequester.Delete(presignedDelRequest.URL)
	if err != nil {
		panic(err)
	}
	log.Printf("%v object %v with presigned URL returned %v.\n", presignedDelRequest.Method,
		uploadKey, delResponse.StatusCode)
	log.Println(strings.Repeat("-", 88))

	log.Println("Thanks for watching!")
	log.Println(strings.Repeat("-", 88))
}

定义示例用于发出 HTTP 请求的 HTTP 请求包装器。

// IHttpRequester abstracts HTTP requests into an interface so it can be mocked during
// unit testing.
type IHttpRequester interface {
	Get(url string) (resp *http.Response, err error)
	Put(url string, contentLength int64, body io.Reader) (resp *http.Response, err error)
	Delete(url string) (resp *http.Response, err error)
}

// HttpRequester uses the net/http package to make HTTP requests during the scenario.
type HttpRequester struct{}

func (httpReq HttpRequester) Get(url string) (resp *http.Response, err error) {
	return http.Get(url)
}
func (httpReq HttpRequester) Put(url string, contentLength int64, body io.Reader) (resp *http.Response, err error) {
	putRequest, err := http.NewRequest("PUT", url, body)
	if err != nil {
		return nil, err
	}
	putRequest.ContentLength = contentLength
	return http.DefaultClient.Do(putRequest)
}
func (httpReq HttpRequester) Delete(url string) (resp *http.Response, err error) {
	delRequest, err := http.NewRequest("DELETE", url, nil)
	if err != nil {
		return nil, err
	}
	return http.DefaultClient.Do(delRequest)
}

    /**
     * Create a presigned URL for uploading a String object.
     * @param bucketName - The name of the bucket.
     * @param keyName - The name of the object.
     * @return - The presigned URL for an HTTP PUT.
     */
    public URL createSignedUrlForStringPut(String bucketName, String keyName) {
        try (S3Presigner presigner = S3Presigner.create()) {

            PutObjectRequest objectRequest = PutObjectRequest.builder()
                    .bucket(bucketName)
                    .key(keyName)
                    .contentType("text/plain")
                    .build();

            PutObjectPresignRequest presignRequest = PutObjectPresignRequest.builder()
                    .signatureDuration(Duration.ofMinutes(10))  // The URL will expire in 10 minutes.
                    .putObjectRequest(objectRequest)
                    .build();

            PresignedPutObjectRequest presignedRequest = presigner.presignPutObject(presignRequest);
            String myURL = presignedRequest.url().toString();
            logger.info("Presigned URL to upload to: [{}]", myURL);
            logger.info("Which HTTP method needs to be used when uploading: [{}]", presignedRequest.httpRequest().method());

            return presignedRequest.url();
        }
    }

    /**
     * Use the JDK HttpURLConnection (since v1.1) class to upload a String, but you can
     * use any HTTP client.
     * @param presignedUrl - The presigned URL.
     */
    public void useHttpUrlConnectionToPutString(URL presignedUrl) {
        try {
            // Create the connection and use it to upload the new object by using the presigned URL.
            HttpURLConnection connection = (HttpURLConnection) presignedUrl.openConnection();
            connection.setDoOutput(true);
            connection.setRequestProperty("Content-Type", "text/plain");
            connection.setRequestMethod("PUT");
            OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());
            out.write("This text was uploaded as an object by using a presigned URL.");
            out.close();

            connection.getResponseCode();
            logger.info("HTTP response code is " + connection.getResponseCode());

        } catch (S3Exception | IOException e) {
            logger.error(e.getMessage(), e);
        }
    }

    /**
     * Use the JDK HttpClient class (since v11) to upload a String,
     * but you can use any HTTP client.
     * @param presignedUrl - The presigned URL.
     */
    public void useHttpClientToPutString(URL presignedUrl) {
        HttpClient httpClient = HttpClient.newHttpClient();
        try {
            final HttpResponse<Void> response = httpClient.send(HttpRequest.newBuilder()
                            .uri(presignedUrl.toURI())
                            .header("Content-Type", "text/plain")
                            .PUT(HttpRequest.BodyPublishers.ofString("This text was uploaded as an object by using a presigned URL."))
                            .build(),
                    HttpResponse.BodyHandlers.discarding());
            logger.info("HTTP response code is " + response.statusCode());
        } catch (S3Exception | IOException | URISyntaxException | InterruptedException e) {
            logger.error(e.getMessage(), e);
        }
    }

创建预签名 URL 以将对象上传到桶。

import https from "https";
import { PutObjectCommand, S3Client } from "@aws-sdk/client-s3";
import { fromIni } from "@aws-sdk/credential-providers";
import { HttpRequest } from "@smithy/protocol-http";
import {
  getSignedUrl,
  S3RequestPresigner,
} from "@aws-sdk/s3-request-presigner";
import { parseUrl } from "@smithy/url-parser";
import { formatUrl } from "@aws-sdk/util-format-url";
import { Hash } from "@smithy/hash-node";

const createPresignedUrlWithoutClient = async ({ region, bucket, key }) => {
  const url = parseUrl(`https://${bucket}.s3.${region}.amazonaws.com/${key}`);
  const presigner = new S3RequestPresigner({
    credentials: fromIni(),
    region,
    sha256: Hash.bind(null, "sha256"),
  });

  const signedUrlObject = await presigner.presign(
    new HttpRequest({ ...url, method: "PUT" }),
  );
  return formatUrl(signedUrlObject);
};

const createPresignedUrlWithClient = ({ region, bucket, key }) => {
  const client = new S3Client({ region });
  const command = new PutObjectCommand({ Bucket: bucket, Key: key });
  return getSignedUrl(client, command, { expiresIn: 3600 });
};

function put(url, data) {
  return new Promise((resolve, reject) => {
    const req = https.request(
      url,
      { method: "PUT", headers: { "Content-Length": new Blob([data]).size } },
      (res) => {
        let responseBody = "";
        res.on("data", (chunk) => {
          responseBody += chunk;
        });
        res.on("end", () => {
          resolve(responseBody);
        });
      },
    );
    req.on("error", (err) => {
      reject(err);
    });
    req.write(data);
    req.end();
  });
}

export const main = async () => {
  const REGION = "us-east-1";
  const BUCKET = "example_bucket";
  const KEY = "example_file.txt";

  // There are two ways to generate a presigned URL.
  // 1. Use createPresignedUrl without the S3 client.
  // 2. Use getSignedUrl in conjunction with the S3 client and GetObjectCommand.
  try {
    const noClientUrl = await createPresignedUrlWithoutClient({
      region: REGION,
      bucket: BUCKET,
      key: KEY,
    });

    const clientUrl = await createPresignedUrlWithClient({
      region: REGION,
      bucket: BUCKET,
      key: KEY,
    });

    // After you get the presigned URL, you can provide your own file
    // data. Refer to put() above.
    console.log("Calling PUT using presigned URL without client");
    await put(noClientUrl, "Hello World");

    console.log("Calling PUT using presigned URL with client");
    await put(clientUrl, "Hello World");

    console.log("\nDone. Check your S3 console.");
  } catch (err) {
    console.error(err);
  }
};

创建预签名 URL 以从桶下载对象。

import { GetObjectCommand, S3Client } from "@aws-sdk/client-s3";
import { fromIni } from "@aws-sdk/credential-providers";
import { HttpRequest } from "@smithy/protocol-http";
import {
  getSignedUrl,
  S3RequestPresigner,
} from "@aws-sdk/s3-request-presigner";
import { parseUrl } from "@smithy/url-parser";
import { formatUrl } from "@aws-sdk/util-format-url";
import { Hash } from "@smithy/hash-node";

const createPresignedUrlWithoutClient = async ({ region, bucket, key }) => {
  const url = parseUrl(`https://${bucket}.s3.${region}.amazonaws.com/${key}`);
  const presigner = new S3RequestPresigner({
    credentials: fromIni(),
    region,
    sha256: Hash.bind(null, "sha256"),
  });

  const signedUrlObject = await presigner.presign(new HttpRequest(url));
  return formatUrl(signedUrlObject);
};

const createPresignedUrlWithClient = ({ region, bucket, key }) => {
  const client = new S3Client({ region });
  const command = new GetObjectCommand({ Bucket: bucket, Key: key });
  return getSignedUrl(client, command, { expiresIn: 3600 });
};

export const main = async () => {
  const REGION = "us-east-1";
  const BUCKET = "example_bucket";
  const KEY = "example_file.jpg";

  try {
    const noClientUrl = await createPresignedUrlWithoutClient({
      region: REGION,
      bucket: BUCKET,
      key: KEY,
    });

    const clientUrl = await createPresignedUrlWithClient({
      region: REGION,
      bucket: BUCKET,
      key: KEY,
    });

    console.log("Presigned URL without client");
    console.log(noClientUrl);
    console.log("\n");

    console.log("Presigned URL with client");
    console.log(clientUrl);
  } catch (err) {
    console.error(err);
  }
};

创建 GetObject 预签名请求并使用 URL 下载对象。

suspend fun getObjectPresigned(s3: S3Client, bucketName: String, keyName: String): String {
    // Create a GetObjectRequest.
    val unsignedRequest = GetObjectRequest {
        bucket = bucketName
        key = keyName
    }

    // Presign the GetObject request.
    val presignedRequest = s3.presignGetObject(unsignedRequest, 24.hours)

    // Use the URL from the presigned HttpRequest in a subsequent HTTP GET request to retrieve the object.
    val objectContents = URL(presignedRequest.url.toString()).readText()

    return objectContents
}

使用高级选项创建 GetObject 预签名请求，然后使用 URL 下载对象。

suspend fun putObjectPresigned(s3: S3Client, bucketName: String, keyName: String, content: String) {
    // Create a PutObjectRequest.
    val unsignedRequest = PutObjectRequest {
        bucket = bucketName
        key = keyName
    }

    // Presign the request.
    val presignedRequest = s3.presignPutObject(unsignedRequest, 24.hours)

    // Use the URL and any headers from the presigned HttpRequest in a subsequent HTTP PUT request to retrieve the object.
    // Create a PUT request using the OKHttpClient API.
    val putRequest = Request
        .Builder()
        .url(presignedRequest.url.toString())
        .apply {
            presignedRequest.headers.forEach { key, values ->
                header(key, values.joinToString(", "))
            }
        }
        .put(content.toRequestBody())
        .build()

    val response = OkHttpClient().newCall(putRequest).execute()
    assert(response.isSuccessful)
}

创建 PutObject 预签名请求并使用它上传对象。

suspend fun getObjectPresignedMoreOptions(s3: S3Client, bucketName: String, keyName: String): HttpRequest {
    // Create a GetObjectRequest.
    val unsignedRequest = GetObjectRequest {
        bucket = bucketName
        key = keyName
    }

    // Presign the GetObject request.
    val presignedRequest = s3.presignGetObject(unsignedRequest, signer = CrtAwsSigner) {
        signingDate = Instant.now() + 12.hours // Presigned request can be used 12 hours from now.
        algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC
        signatureType = AwsSignatureType.HTTP_REQUEST_VIA_QUERY_PARAMS
        expiresAfter = 8.hours // Presigned request expires 8 hours later.
    }
    return presignedRequest
}

生成可在有限时间内执行 S3 操作的预签名 URL。使用请求软件包通过 URL 发出请求。

import argparse
import logging
import boto3
from botocore.exceptions import ClientError
import requests

logger = logging.getLogger(__name__)


def generate_presigned_url(s3_client, client_method, method_parameters, expires_in):
    """
    Generate a presigned Amazon S3 URL that can be used to perform an action.

    :param s3_client: A Boto3 Amazon S3 client.
    :param client_method: The name of the client method that the URL performs.
    :param method_parameters: The parameters of the specified client method.
    :param expires_in: The number of seconds the presigned URL is valid for.
    :return: The presigned URL.
    """
    try:
        url = s3_client.generate_presigned_url(
            ClientMethod=client_method, Params=method_parameters, ExpiresIn=expires_in
        )
        logger.info("Got presigned URL: %s", url)
    except ClientError:
        logger.exception(
            "Couldn't get a presigned URL for client method '%s'.", client_method
        )
        raise
    return url


def usage_demo():
    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    print("-" * 88)
    print("Welcome to the Amazon S3 presigned URL demo.")
    print("-" * 88)

    parser = argparse.ArgumentParser()
    parser.add_argument("bucket", help="The name of the bucket.")
    parser.add_argument(
        "key",
        help="For a GET operation, the key of the object in Amazon S3. For a "
        "PUT operation, the name of a file to upload.",
    )
    parser.add_argument("action", choices=("get", "put"), help="The action to perform.")
    args = parser.parse_args()

    s3_client = boto3.client("s3")
    client_action = "get_object" if args.action == "get" else "put_object"
    url = generate_presigned_url(
        s3_client, client_action, {"Bucket": args.bucket, "Key": args.key}, 1000
    )

    print("Using the Requests package to send a request to the URL.")
    response = None
    if args.action == "get":
        response = requests.get(url)
    elif args.action == "put":
        print("Putting data to the URL.")
        try:
            with open(args.key, "r") as object_file:
                object_text = object_file.read()
            response = requests.put(url, data=object_text)
        except FileNotFoundError:
            print(
                f"Couldn't find {args.key}. For a PUT operation, the key must be the "
                f"name of a file that exists on your computer."
            )

    if response is not None:
        print("Got response:")
        print(f"Status: {response.status_code}")
        print(response.text)

    print("-" * 88)


if __name__ == "__main__":
    usage_demo()

生成预签名 POST 请求以上传文件。

class BucketWrapper:
    """Encapsulates S3 bucket actions."""

    def __init__(self, bucket):
        """
        :param bucket: A Boto3 Bucket resource. This is a high-level resource in Boto3
                       that wraps bucket actions in a class-like structure.
        """
        self.bucket = bucket
        self.name = bucket.name


    def generate_presigned_post(self, object_key, expires_in):
        """
        Generate a presigned Amazon S3 POST request to upload a file.
        A presigned POST can be used for a limited time to let someone without an AWS
        account upload a file to a bucket.

        :param object_key: The object key to identify the uploaded object.
        :param expires_in: The number of seconds the presigned POST is valid.
        :return: A dictionary that contains the URL and form fields that contain
                 required access data.
        """
        try:
            response = self.bucket.meta.client.generate_presigned_post(
                Bucket=self.bucket.name, Key=object_key, ExpiresIn=expires_in
            )
            logger.info("Got presigned POST URL: %s", response["url"])
        except ClientError:
            logger.exception(
                "Couldn't get a presigned POST URL for bucket '%s' and object '%s'",
                self.bucket.name,
                object_key,
            )
            raise
        return response

require "aws-sdk-s3"
require "net/http"

# Creates a presigned URL that can be used to upload content to an object.
#
# @param bucket [Aws::S3::Bucket] An existing Amazon S3 bucket.
# @param object_key [String] The key to give the uploaded object.
# @return [URI, nil] The parsed URI if successful; otherwise nil.
def get_presigned_url(bucket, object_key)
  url = bucket.object(object_key).presigned_url(:put)
  puts "Created presigned URL: #{url}"
  URI(url)
rescue Aws::Errors::ServiceError => e
  puts "Couldn't create presigned URL for #{bucket.name}:#{object_key}. Here's why: #{e.message}"
end

def run_demo
  bucket_name = "doc-example-bucket"
  object_key = "my-file.txt"
  object_content = "This is the content of my-file.txt."

  bucket = Aws::S3::Bucket.new(bucket_name)
  presigned_url = get_presigned_url(bucket, object_key)
  return unless presigned_url

  response = Net::HTTP.start(presigned_url.host) do |http|
    http.send_request("PUT", presigned_url.request_uri, object_content, "content_type" => "")
  end

  case response
  when Net::HTTPSuccess
    puts "Content uploaded!"
  else
    puts response.value
  end
end

run_demo if $PROGRAM_NAME == __FILE__

创建预签名请求以 GET 和 PUT S3 对象。

async fn get_object(
    client: &Client,
    bucket: &str,
    object: &str,
    expires_in: u64,
) -> Result<(), Box<dyn Error>> {
    let expires_in = Duration::from_secs(expires_in);
    let presigned_request = client
        .get_object()
        .bucket(bucket)
        .key(object)
        .presigned(PresigningConfig::expires_in(expires_in)?)
        .await?;

    println!("Object URI: {}", presigned_request.uri());

    Ok(())
}

async fn put_object(
    client: &Client,
    bucket: &str,
    object: &str,
    expires_in: u64,
) -> Result<(), Box<dyn Error>> {
    let expires_in = Duration::from_secs(expires_in);

    let presigned_request = client
        .put_object()
        .bucket(bucket)
        .key(object)
        .presigned(PresigningConfig::expires_in(expires_in)?)
        .await?;

    println!("Object URI: {}", presigned_request.uri());

    Ok(())
}