通过 Amazon S3 触发器调用 Lambda 函数 - Amazon Lambda
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通过 Amazon S3 触发器调用 Lambda 函数

以下代码示例演示了如何实现一个 Lambda 函数,该函数接收通过将对象上传到 S3 存储桶而触发的事件。该函数从事件参数中检索 S3 存储桶名称和对象密钥,并调用 Amazon S3 API 来检索和记录对象的内容类型。

.NET
Amazon SDK for .NET
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 .NET 将 S3 事件与 Lambda 结合使用。

using System.Threading.Tasks; using Amazon.Lambda.Core; using Amazon.S3; using System; using Amazon.Lambda.S3Events; using System.Web; // Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class. [assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))] namespace S3Integration { public class Function { private static AmazonS3Client _s3Client; public Function() : this(null) { } internal Function(AmazonS3Client s3Client) { _s3Client = s3Client ?? new AmazonS3Client(); } public async Task<string> Handler(S3Event evt, ILambdaContext context) { try { if (evt.Records.Count <= 0) { context.Logger.LogLine("Empty S3 Event received"); return string.Empty; } var bucket = evt.Records[0].S3.Bucket.Name; var key = HttpUtility.UrlDecode(evt.Records[0].S3.Object.Key); context.Logger.LogLine($"Request is for {bucket} and {key}"); var objectResult = await _s3Client.GetObjectAsync(bucket, key); context.Logger.LogLine($"Returning {objectResult.Key}"); return objectResult.Key; } catch (Exception e) { context.Logger.LogLine($"Error processing request - {e.Message}"); return string.Empty; } } } }
Go
适用于 Go V2 的 SDK
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 Go 将 S3 事件与 Lambda 结合使用。

package main import ( "context" "log" "github.com/aws/aws-lambda-go/events" "github.com/aws/aws-lambda-go/lambda" "github.com/aws/aws-sdk-go-v2/config" "github.com/aws/aws-sdk-go-v2/service/s3" ) func handler(ctx context.Context, s3Event events.S3Event) error { sdkConfig, err := config.LoadDefaultConfig(ctx) if err != nil { log.Printf("failed to load default config: %s", err) return err } s3Client := s3.NewFromConfig(sdkConfig) for _, record := range s3Event.Records { bucket := record.S3.Bucket.Name key := record.S3.Object.URLDecodedKey headOutput, err := s3Client.HeadObject(ctx, &s3.HeadObjectInput{ Bucket: &bucket, Key: &key, }) if err != nil { log.Printf("error getting head of object %s/%s: %s", bucket, key, err) return err } log.Printf("successfully retrieved %s/%s of type %s", bucket, key, *headOutput.ContentType) } return nil } func main() { lambda.Start(handler) }
Java
SDK for Java 2.x
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 Java 将 S3 事件与 Lambda 结合使用。

package example; import software.amazon.awssdk.services.s3.model.HeadObjectRequest; import software.amazon.awssdk.services.s3.model.HeadObjectResponse; import software.amazon.awssdk.services.s3.S3Client; import com.amazonaws.services.lambda.runtime.Context; import com.amazonaws.services.lambda.runtime.RequestHandler; import com.amazonaws.services.lambda.runtime.events.S3Event; import com.amazonaws.services.lambda.runtime.events.models.s3.S3EventNotification.S3EventNotificationRecord; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class Handler implements RequestHandler<S3Event, String> { private static final Logger logger = LoggerFactory.getLogger(Handler.class); @Override public String handleRequest(S3Event s3event, Context context) { try { S3EventNotificationRecord record = s3event.getRecords().get(0); String srcBucket = record.getS3().getBucket().getName(); String srcKey = record.getS3().getObject().getUrlDecodedKey(); S3Client s3Client = S3Client.builder().build(); HeadObjectResponse headObject = getHeadObject(s3Client, srcBucket, srcKey); logger.info("Successfully retrieved " + srcBucket + "/" + srcKey + " of type " + headObject.contentType()); return "Ok"; } catch (Exception e) { throw new RuntimeException(e); } } private HeadObjectResponse getHeadObject(S3Client s3Client, String bucket, String key) { HeadObjectRequest headObjectRequest = HeadObjectRequest.builder() .bucket(bucket) .key(key) .build(); return s3Client.headObject(headObjectRequest); } }
JavaScript
SDK for JavaScript (v2)
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 JavaScript 将 S3 事件与 Lambda 结合使用。

const aws = require('aws-sdk'); const s3 = new aws.S3({ apiVersion: '2006-03-01' }); exports.handler = async (event, context) => { // Get the object from the event and show its content type const bucket = event.Records[0].s3.bucket.name; const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' ')); const params = { Bucket: bucket, Key: key, }; try { const { ContentType } = await s3.headObject(params).promise(); console.log('CONTENT TYPE:', ContentType); return ContentType; } catch (err) { console.log(err); const message = `Error getting object ${key} from bucket ${bucket}. Make sure they exist and your bucket is in the same region as this function.`; console.log(message); throw new Error(message); } };

使用 TypeScript 将 S3 事件与 Lambda 结合使用。

import { S3Event } from 'aws-lambda'; import { S3Client, HeadObjectCommand } from '@aws-sdk/client-s3'; const s3 = new S3Client({ region: process.env.AWS_REGION }); export const handler = async (event: S3Event): Promise<string | undefined> => { // Get the object from the event and show its content type const bucket = event.Records[0].s3.bucket.name; const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' ')); const params = { Bucket: bucket, Key: key, }; try { const { ContentType } = await s3.send(new HeadObjectCommand(params)); console.log('CONTENT TYPE:', ContentType); return ContentType; } catch (err) { console.log(err); const message = `Error getting object ${key} from bucket ${bucket}. Make sure they exist and your bucket is in the same region as this function.`; console.log(message); throw new Error(message); } };
Python
SDK for Python(Boto3)
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 Python 将 S3 事件与 Lambda 结合使用。

import json import urllib.parse import boto3 print('Loading function') s3 = boto3.client('s3') def lambda_handler(event, context): #print("Received event: " + json.dumps(event, indent=2)) # Get the object from the event and show its content type bucket = event['Records'][0]['s3']['bucket']['name'] key = urllib.parse.unquote_plus(event['Records'][0]['s3']['object']['key'], encoding='utf-8') try: response = s3.get_object(Bucket=bucket, Key=key) print("CONTENT TYPE: " + response['ContentType']) return response['ContentType'] except Exception as e: print(e) print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket)) raise e
Rust
适用于 Rust 的 SDK
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 Rust 将 S3 事件与 Lambda 结合使用。

use aws_lambda_events::event::s3::S3Event; use aws_sdk_s3::{Client}; use lambda_runtime::{run, service_fn, Error, LambdaEvent}; /// Main function #[tokio::main] async fn main() -> Result<(), Error> { tracing_subscriber::fmt() .with_max_level(tracing::Level::INFO) .with_target(false) .without_time() .init(); // Initialize the AWS SDK for Rust let config = aws_config::load_from_env().await; let s3_client = Client::new(&config); let res = run(service_fn(|request: LambdaEvent<S3Event>| { function_handler(&s3_client, request) })).await; res } async fn function_handler( s3_client: &Client, evt: LambdaEvent<S3Event> ) -> Result<(), Error> { tracing::info!(records = ?evt.payload.records.len(), "Received request from SQS"); if evt.payload.records.len() == 0 { tracing::info!("Empty S3 event received"); } let bucket = evt.payload.records[0].s3.bucket.name.as_ref().expect("Bucket name to exist"); let key = evt.payload.records[0].s3.object.key.as_ref().expect("Object key to exist"); tracing::info!("Request is for {} and object {}", bucket, key); let s3_get_object_result = s3_client .get_object() .bucket(bucket) .key(key) .send() .await; match s3_get_object_result { Ok(_) => tracing::info!("S3 Get Object success, the s3GetObjectResult contains a 'body' property of type ByteStream"), Err(_) => tracing::info!("Failure with S3 Get Object request") } Ok(()) }

有关 Amazon SDK 开发人员指南和代码示例的完整列表,请参阅 将 Lambda 与 Amazon SDK 配合使用。本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。