将 Amazon Lambda 与 Amazon RDS 结合使用 - Amazon Lambda
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将 Amazon Lambda 与 Amazon RDS 结合使用

您可以将 Lambda 函数直接连接到 Amazon Relational Database Service(Amazon RDS),也可以通过 Amazon RDS 代理连接。直接连接适用于简单的场景,而在生产中则推荐使用代理。数据库代理管理共享数据库连接池,从而让函数能够在不耗尽数据库连接的情况下达到高并发级别。

对于频繁建立短数据库连接或打开和关闭大量数据库连接的 Lambda 函数,我们建议使用 Amazon RDS 代理。

配置函数

在 Lambda 控制台中,您可以预置和配置 Amazon RDS 数据库实例和代理资源。有关更多信息,请参阅配置选项卡下的 RDS 数据库。或者,您也可以在 Amazon RDS 控制台中创建和配置到 Lambda 函数的连接。

  • 要连接到数据库,您的函数必须位于数据库在其中运行的 Amazon VPC。

  • 您可以将 Amazon RDS 数据库与 MySQL、MariaDB、PostgreSQL 或 Microsoft SQL Server 引擎一起使用。

  • 您也可以将 Aurora 数据库集群与 MySQL 或 PostgreSQL 引擎一起使用。

  • 您需要提供用于数据库身份验证的 Secrets Manager 密钥。

  • IAM 角色必须提供使用密钥的权限和必须允许 Amazon RDS 代入角色的信任策略。

  • 使用控制台配置 Amazon RDS 资源并将其连接到函数的 IAM 主体,必须具有以下权限:

    注意

    只有在将 Amazon RDS 代理配置为管理数据库连接池时,才需要用到 Amazon RDS 代理权限。

    例 权限策略
    { "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "ec2:CreateSecurityGroup", "ec2:DescribeSecurityGroups", "ec2:DescribeSubnets", "ec2:DescribeVpcs", "ec2:AuthorizeSecurityGroupIngress", "ec2:AuthorizeSecurityGroupEgress", "ec2:RevokeSecurityGroupEgress", "ec2:CreateNetworkInterface", "ec2:DeleteNetworkInterface", "ec2:DescribeNetworkInterfaces" ], "Resource": "*" }, { "Effect": "Allow", "Action": [ "rds-db:connect", "rds:CreateDBProxy", "rds:CreateDBInstance", "rds:CreateDBSubnetGroup", "rds:DescribeDBClusters", "rds:DescribeDBInstances", "rds:DescribeDBSubnetGroups", "rds:DescribeDBProxies", "rds:DescribeDBProxyTargets", "rds:DescribeDBProxyTargetGroups", "rds:RegisterDBProxyTargets", "rds:ModifyDBInstance", "rds:ModifyDBProxy" ], "Resource": "*" }, { "Effect": "Allow", "Action": [ "lambda:CreateFunction", "lambda:ListFunctions", "lambda:UpdateFunctionConfiguration" ], "Resource": "*" }, { "Effect": "Allow", "Action": [ "iam:AttachRolePolicy", "iam:AttachPolicy", "iam:CreateRole", "iam:CreatePolicy" ], "Resource": "*" }, { "Effect": "Allow", "Action": [ "secretsmanager:GetResourcePolicy", "secretsmanager:GetSecretValue", "secretsmanager:DescribeSecret", "secretsmanager:ListSecretVersionIds", "secretsmanager:CreateSecret" ], "Resource": "*" } ] }

Amazon RDS 根据数据库实例大小按小时收取代理费率,详情请参阅 RDS 代理定价。有关通用代理连接的更多信息,请参阅《Amazon RDS 用户指南》中的使用 Amazon RDS 代理

Lambda 和 Amazon RDS 设置

Lambda 和 Amazon RDS 控制台都将协助您自动配置一些必要资源,以便在 Lambda 和 Amazon RDS 之间建立连接。

使用 Lambda 函数连接到 Amazon RDS 数据库

以下代码示例显示如何实现连接到 Amazon RDS 数据库的 Lambda 函数。该函数发出一个简单的数据库请求并返回结果。

Go
适用于 Go V2 的 SDK
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 Go 连接到 Amazon RDS 数据库。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 /* Golang v2 code here. */ package main import ( "context" "database/sql" "encoding/json" "fmt" "os" "github.com/aws/aws-lambda-go/lambda" "github.com/aws/aws-sdk-go-v2/config" "github.com/aws/aws-sdk-go-v2/feature/rds/auth" _ "github.com/go-sql-driver/mysql" ) type MyEvent struct { Name string `json:"name"` } func HandleRequest(event *MyEvent) (map[string]interface{}, error) { var dbName string = os.Getenv("DatabaseName") var dbUser string = os.Getenv("DatabaseUser") var dbHost string = os.Getenv("DBHost") // Add hostname without https var dbPort int = os.Getenv("Port") // Add port number var dbEndpoint string = fmt.Sprintf("%s:%d", dbHost, dbPort) var region string = os.Getenv("AWS_REGION") cfg, err := config.LoadDefaultConfig(context.TODO()) if err != nil { panic("configuration error: " + err.Error()) } authenticationToken, err := auth.BuildAuthToken( context.TODO(), dbEndpoint, region, dbUser, cfg.Credentials) if err != nil { panic("failed to create authentication token: " + err.Error()) } dsn := fmt.Sprintf("%s:%s@tcp(%s)/%s?tls=true&allowCleartextPasswords=true", dbUser, authenticationToken, dbEndpoint, dbName, ) db, err := sql.Open("mysql", dsn) if err != nil { panic(err) } defer db.Close() var sum int err = db.QueryRow("SELECT ?+? AS sum", 3, 2).Scan(&sum) if err != nil { panic(err) } s := fmt.Sprint(sum) message := fmt.Sprintf("The selected sum is: %s", s) messageBytes, err := json.Marshal(message) if err != nil { return nil, err } messageString := string(messageBytes) return map[string]interface{}{ "statusCode": 200, "headers": map[string]string{"Content-Type": "application/json"}, "body": messageString, }, nil } func main() { lambda.Start(HandleRequest) }
Java
SDK for Java 2.x
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 Java 连接到 Amazon RDS 数据库。

import com.amazonaws.services.lambda.runtime.Context; import com.amazonaws.services.lambda.runtime.RequestHandler; import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent; import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent; import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.rdsdata.RdsDataClient; import software.amazon.awssdk.services.rdsdata.model.ExecuteStatementRequest; import software.amazon.awssdk.services.rdsdata.model.ExecuteStatementResponse; import software.amazon.awssdk.services.rdsdata.model.Field; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; public class RdsLambdaHandler implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> { @Override public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent event, Context context) { APIGatewayProxyResponseEvent response = new APIGatewayProxyResponseEvent(); try { // Obtain auth token String token = createAuthToken(); // Define connection configuration String connectionString = String.format("jdbc:mysql://%s:%s/%s?useSSL=true&requireSSL=true", System.getenv("ProxyHostName"), System.getenv("Port"), System.getenv("DBName")); // Establish a connection to the database try (Connection connection = DriverManager.getConnection(connectionString, System.getenv("DBUserName"), token); PreparedStatement statement = connection.prepareStatement("SELECT ? + ? AS sum")) { statement.setInt(1, 3); statement.setInt(2, 2); try (ResultSet resultSet = statement.executeQuery()) { if (resultSet.next()) { int sum = resultSet.getInt("sum"); response.setStatusCode(200); response.setBody("The selected sum is: " + sum); } } } } catch (Exception e) { response.setStatusCode(500); response.setBody("Error: " + e.getMessage()); } return response; } private String createAuthToken() { // Create RDS Data Service client RdsDataClient rdsDataClient = RdsDataClient.builder() .region(Region.of(System.getenv("AWS_REGION"))) .credentialsProvider(DefaultCredentialsProvider.create()) .build(); // Define authentication request ExecuteStatementRequest request = ExecuteStatementRequest.builder() .resourceArn(System.getenv("ProxyHostName")) .secretArn(System.getenv("DBUserName")) .database(System.getenv("DBName")) .sql("SELECT 'RDS IAM Authentication'") .build(); // Execute request and obtain authentication token ExecuteStatementResponse response = rdsDataClient.executeStatement(request); Field tokenField = response.records().get(0).get(0); return tokenField.stringValue(); } }
JavaScript
SDK for JavaScript (v2)
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 Javascript 连接到 Amazon RDS 数据库。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 /* Node.js code here. */ // ES6+ example import { Signer } from "@aws-sdk/rds-signer"; import mysql from 'mysql2/promise'; async function createAuthToken() { // Define connection authentication parameters const dbinfo = { hostname: process.env.ProxyHostName, port: process.env.Port, username: process.env.DBUserName, region: process.env.AWS_REGION, } // Create RDS Signer object const signer = new Signer(dbinfo); // Request authorization token from RDS, specifying the username const token = await signer.getAuthToken(); return token; } async function dbOps() { // Obtain auth token const token = await createAuthToken(); // Define connection configuration let connectionConfig = { host: process.env.ProxyHostName, user: process.env.DBUserName, password: token, database: process.env.DBName, ssl: 'Amazon RDS' } // Create the connection to the DB const conn = await mysql.createConnection(connectionConfig); // Obtain the result of the query const [res,] = await conn.execute('select ?+? as sum', [3, 2]); return res; } export const handler = async (event) => { // Execute database flow const result = await dbOps(); // Return result return { statusCode: 200, body: JSON.stringify("The selected sum is: " + result[0].sum) } };
PHP
适用于 PHP 的 SDK
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 PHP 连接到 Amazon RDS 数据库。

<?php # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: Apache-2.0 # using bref/bref and bref/logger for simplicity use Bref\Context\Context; use Bref\Event\Handler as StdHandler; use Bref\Logger\StderrLogger; use Aws\Rds\AuthTokenGenerator; use Aws\Credentials\CredentialProvider; require __DIR__ . '/vendor/autoload.php'; class Handler implements StdHandler { private StderrLogger $logger; public function __construct(StderrLogger $logger) { $this->logger = $logger; } private function getAuthToken(): string { // Define connection authentication parameters $dbConnection = [ 'hostname' => getenv('DB_HOSTNAME'), 'port' => getenv('DB_PORT'), 'username' => getenv('DB_USERNAME'), 'region' => getenv('AWS_REGION'), ]; // Create RDS AuthTokenGenerator object $generator = new AuthTokenGenerator(CredentialProvider::defaultProvider()); // Request authorization token from RDS, specifying the username return $generator->createToken( $dbConnection['hostname'] . ':' . $dbConnection['port'], $dbConnection['region'], $dbConnection['username'] ); } private function getQueryResults() { // Obtain auth token $token = $this->getAuthToken(); // Define connection configuration $connectionConfig = [ 'host' => getenv('DB_HOSTNAME'), 'user' => getenv('DB_USERNAME'), 'password' => $token, 'database' => getenv('DB_NAME'), ]; // Create the connection to the DB $conn = new PDO( "mysql:host={$connectionConfig['host']};dbname={$connectionConfig['database']}", $connectionConfig['user'], $connectionConfig['password'], [ PDO::MYSQL_ATTR_SSL_CA => '/path/to/rds-ca-2019-root.pem', PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT => true, ] ); // Obtain the result of the query $stmt = $conn->prepare('SELECT ?+? AS sum'); $stmt->execute([3, 2]); return $stmt->fetch(PDO::FETCH_ASSOC); } /** * @param mixed $event * @param Context $context * @return array */ public function handle(mixed $event, Context $context): array { $this->logger->info("Processing query"); // Execute database flow $result = $this->getQueryResults(); return [ 'sum' => $result['sum'] ]; } } $logger = new StderrLogger(); return new Handler($logger);
Python
SDK for Python(Boto3)
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 Python 连接到 Amazon RDS 数据库。

import json import os import boto3 import pymysql # RDS settings proxy_host_name = os.environ['PROXY_HOST_NAME'] port = int(os.environ['PORT']) db_name = os.environ['DB_NAME'] db_user_name = os.environ['DB_USER_NAME'] aws_region = os.environ['AWS_REGION'] # Fetch RDS Auth Token def get_auth_token(): client = boto3.client('rds') token = client.generate_db_auth_token( DBHostname=proxy_host_name, Port=port DBUsername=db_user_name Region=aws_region ) return token def lambda_handler(event, context): token = get_auth_token() try: connection = pymysql.connect( host=proxy_host_name, user=db_user_name, password=token, db=db_name, port=port, ssl={'ca': 'Amazon RDS'} # Ensure you have the CA bundle for SSL connection ) with connection.cursor() as cursor: cursor.execute('SELECT %s + %s AS sum', (3, 2)) result = cursor.fetchone() return result except Exception as e: return (f"Error: {str(e)}") # Return an error message if an exception occurs
Ruby
适用于 Ruby 的 SDK
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 Ruby 连接到 Amazon RDS 数据库。

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: Apache-2.0 # Ruby code here. require 'aws-sdk-rds' require 'json' require 'mysql2' def lambda_handler(event:, context:) endpoint = ENV['DBEndpoint'] # Add the endpoint without https" port = ENV['Port'] # 3306 user = ENV['DBUser'] region = ENV['DBRegion'] # 'us-east-1' db_name = ENV['DBName'] credentials = Aws::Credentials.new( ENV['AWS_ACCESS_KEY_ID'], ENV['AWS_SECRET_ACCESS_KEY'], ENV['AWS_SESSION_TOKEN'] ) rds_client = Aws::RDS::AuthTokenGenerator.new( region: region, credentials: credentials ) token = rds_client.auth_token( endpoint: endpoint+ ':' + port, user_name: user, region: region ) begin conn = Mysql2::Client.new( host: endpoint, username: user, password: token, port: port, database: db_name, sslca: '/var/task/global-bundle.pem', sslverify: true, enable_cleartext_plugin: true ) a = 3 b = 2 result = conn.query("SELECT #{a} + #{b} AS sum").first['sum'] puts result conn.close { statusCode: 200, body: result.to_json } rescue => e puts "Database connection failed due to #{e}" end end
Rust
适用于 Rust 的 SDK
注意

查看 GitHub,了解更多信息。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。

在 Lambda 函数中使用 Rust 连接到 Amazon RDS 数据库。

use aws_config::BehaviorVersion; use aws_credential_types::provider::ProvideCredentials; use aws_sigv4::{ http_request::{sign, SignableBody, SignableRequest, SigningSettings}, sign::v4, }; use lambda_runtime::{run, service_fn, Error, LambdaEvent}; use serde_json::{json, Value}; use sqlx::postgres::PgConnectOptions; use std::env; use std::time::{Duration, SystemTime}; const RDS_CERTS: &[u8] = include_bytes!("global-bundle.pem"); async fn generate_rds_iam_token( db_hostname: &str, port: u16, db_username: &str, ) -> Result<String, Error> { let config = aws_config::load_defaults(BehaviorVersion::v2024_03_28()).await; let credentials = config .credentials_provider() .expect("no credentials provider found") .provide_credentials() .await .expect("unable to load credentials"); let identity = credentials.into(); let region = config.region().unwrap().to_string(); let mut signing_settings = SigningSettings::default(); signing_settings.expires_in = Some(Duration::from_secs(900)); signing_settings.signature_location = aws_sigv4::http_request::SignatureLocation::QueryParams; let signing_params = v4::SigningParams::builder() .identity(&identity) .region(&region) .name("rds-db") .time(SystemTime::now()) .settings(signing_settings) .build()?; let url = format!( "https://{db_hostname}:{port}/?Action=connect&DBUser={db_user}", db_hostname = db_hostname, port = port, db_user = db_username ); let signable_request = SignableRequest::new("GET", &url, std::iter::empty(), SignableBody::Bytes(&[])) .expect("signable request"); let (signing_instructions, _signature) = sign(signable_request, &signing_params.into())?.into_parts(); let mut url = url::Url::parse(&url).unwrap(); for (name, value) in signing_instructions.params() { url.query_pairs_mut().append_pair(name, &value); } let response = url.to_string().split_off("https://".len()); Ok(response) } #[tokio::main] async fn main() -> Result<(), Error> { run(service_fn(handler)).await } async fn handler(_event: LambdaEvent<Value>) -> Result<Value, Error> { let db_host = env::var("DB_HOSTNAME").expect("DB_HOSTNAME must be set"); let db_port = env::var("DB_PORT") .expect("DB_PORT must be set") .parse::<u16>() .expect("PORT must be a valid number"); let db_name = env::var("DB_NAME").expect("DB_NAME must be set"); let db_user_name = env::var("DB_USERNAME").expect("DB_USERNAME must be set"); let token = generate_rds_iam_token(&db_host, db_port, &db_user_name).await?; let opts = PgConnectOptions::new() .host(&db_host) .port(db_port) .username(&db_user_name) .password(&token) .database(&db_name) .ssl_root_cert_from_pem(RDS_CERTS.to_vec()) .ssl_mode(sqlx::postgres::PgSslMode::Require); let pool = sqlx::postgres::PgPoolOptions::new() .connect_with(opts) .await?; let result: i32 = sqlx::query_scalar("SELECT $1 + $2") .bind(3) .bind(2) .fetch_one(&pool) .await?; println!("Result: {:?}", result); Ok(json!({ "statusCode": 200, "content-type": "text/plain", "body": format!("The selected sum is: {result}") })) }

处理 Amazon RDS 中的事件通知

您可以使用 Lambda 处理 Amazon RDS 数据库中的事件通知。Amazon RDS 将通知发送到 Amazon Simple Notification Service (Amazon SNS) 主题,您可以将其配置为调用 Lambda 函数。Amazon SNS 将来自 Amazon RDS 的消息封装在其自己的事件文档中,并将其发送到您的函数。

有关配置 Amazon RDS 数据库以发送通知的详细信息,请参阅使用 Amazon RDS 事件通知

例 Amazon SNS 事件中的 Amazon RDS 消息
{ "Records": [ { "EventVersion": "1.0", "EventSubscriptionArn": "arn:aws:sns:us-east-2:123456789012:rds-lambda:21be56ed-a058-49f5-8c98-aedd2564c486", "EventSource": "aws:sns", "Sns": { "SignatureVersion": "1", "Timestamp": "2023-01-02T12:45:07.000Z", "Signature": "tcc6faL2yUC6dgZdmrwh1Y4cGa/ebXEkAi6RibDsvpi+tE/1+82j...65r==", "SigningCertUrl": "https://sns.us-east-2.amazonaws.com/SimpleNotificationService-ac565b8b1a6c5d002d285f9598aa1d9b.pem", "MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e", "Message": "{\"Event Source\":\"db-instance\",\"Event Time\":\"2023-01-02 12:45:06.000\",\"Identifier Link\":\"https://console.aws.amazon.com/rds/home?region=eu-west-1#dbinstance:id=dbinstanceid\",\"Source ID\":\"dbinstanceid\",\"Event ID\":\"http://docs.amazonwebservices.com/AmazonRDS/latest/UserGuide/USER_Events.html#RDS-EVENT-0002\",\"Event Message\":\"Finished DB Instance backup\"}", "MessageAttributes": {}, "Type": "Notification", "UnsubscribeUrl": "https://sns.us-east-2.amazonaws.com/?Action=Unsubscribe&amp;SubscriptionArn=arn:aws:sns:us-east-2:123456789012:test-lambda:21be56ed-a058-49f5-8c98-aedd2564c486", "TopicArn":"arn:aws:sns:us-east-2:123456789012:sns-lambda", "Subject": "RDS Notification Message" } } ] }

Lambda 和 Amazon RDS 教程

  • 使用 Lambda 函数访问 Amazon RDS 数据库 – 在《Amazon RDS 用户指南》中,了解如何使用 Lambda 函数通过 Amazon RDS 代理将数据写入 Amazon RDS 数据库。Lambda 函数将从 Amazon SQS 队列中读取记录,每当添加消息时,都将新的项目写入数据库的表中。