This snippet demonstrates how to connect to an Amazon RDS database from an AWS Lambda function with IAM authentication. It connects directly to the RDS instance or cluster endpoint and does not require an RDS Proxy. This snippet is valid for MariaDB/MySQL or Aurora for MySQL
Amazon Relational Database Service (Amazon RDS) is a collection of managed services that makes it simple to set up, operate, and scale databases in the cloud. Choose from seven popular engines. Connect to an RDS database using IAM authentication.
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Copy the code into your Lambda function
Follow the AWS Lambda instructions for packaging with dependencies and uploading in .zip format. This snippet uses the go mysql driver
// 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"
"strconv"
"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")
// DBHost is the RDS instance/cluster endpoint (hostname without https).
// An RDS Proxy is not required for IAM authentication.
var dbHost string = os.Getenv("DBHost")
dbPort, err := strconv.Atoi(os.Getenv("Port")) // Add port number
if err != nil {
panic("invalid port number: " + err.Error())
}
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)
}
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