Are there Node.js examples for how to connect to AWS Aurora Serverless PostgreSQL via Lambda

user_5140366 0
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I've set up an AWS Aurora Serverless PostgreSQL DB. I've also got API Gateway running endpoints to Lambda functions. Right now the Lambda functions are connecting to DynamoDB, but RDS is going to work better for my use case.

I've scoured the interwebs for hours but can't seem to find an example of how to access my Aurora Serverless DB via Lambda with Node.js. I'm not sure what imports I need in my function and I'm having a difficult time finding the right methods in the API as well.

Just a basic Node.js example to get me started would be amazingly helpful.

Thanks in advance.

aws-aurora-serverless aws-lambda node.js
3 Answers
user_47105170

I got a response on the AWS Developer Forums that was exactly what I needed to get started.

Evidently to use the PostgreSQL connector you have to build the function locally and import rather than use the online Lambda console.

Here is the example code provided by MrK: https://forums.aws.amazon.com/message.jspa?messageID=919394

//this imports the postgres connector into the file so it can be used
const { Client } = require('pg');

//instantiates a client to connect to the database, connection settings are passed in
const client = new Client({
    user: '<your db username>',
    host: '<your endpoint>',
    database: '<your database name>',
    password: '<your database password>',
    port: 5432
});

//the lambda funtion code
exports.handler = async (event, context, callback) => {

    try {

        await client.connect();
        callback(null, "Connected Successfully");
        //your code here

    } catch (err) {

        callback(null, "Failed to Connect Successfully");
        throw err;
        //error message
    }

    client.end();

};
user_51403660

Somewhat old question but the answer is to either use the AWS.RDSDataService() from the AWS SDK. (See samples/setup here: https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/RDSDataService.html)

Or to use a "wrapper" package which we opted for with the data-api-client.

const dataApiClient = require('data-api-client');

const db = dataApiClient({
  secretArn: process.env.RDS_AURORA_DATA_API_SECRET_ARN || '',
  resourceArn: process.env.RDS_AURORA_DATA_API_ARN || '',
  database: process.env.RDS_AURORA_DATA_API_DB || '',
  region: 'eu-west-1',
  options: {
    endpoint:
      process.env.IS_OFFLINE
        ? process.env.AURORA_LOCAL_ENDPOINT || 'http://0.0.0.0:8080'
        : null
  }
});

If you run a local DB and want to develop locally the options.endpoint to run locally works great with the Docker container koxudaxi/local-data-api. Make sure PG Server is running and then run the Docker cmd:

docker run -d --rm -it --name my-data-api -p 8080:80 -e ENGINE=PostgreSQLJDBC -e POSTGRES_HOST=host.docker.internal -e POSTGRES_PORT=
5432 -e POSTGRES_USER=qipdb_user -e POSTGRES_PASSWORD=password -e RESOURCE_ARN=arn:aws:rds:eu-west-1:00000000000:cluster:dummy -e SECRET_ARN=arn:aws:
secretsmanager:eu-west-1:00000000000:secret:dummy koxudaxi/local-data-api

As the Data API only takes SQL we opted to use a "disconnected" knex instance to produce the SQL (this is completely optional though as normal SQL works directly if preferred):

// knex is only use to produce SQL, it does not have any DB connection!
const connKnex = require('knex');
const knex = connKnex({ client: 'pg' });

Then you can use knex to get the SQL, like:

async function getSomethingFromDB() {
const sql = await knex
    .select('aColumn')
    .from('aTable')
    .where({
      someColumn: 'isSomething'
    })
    .toString();
  const obj = await db.query(sql);

  return !obj.records[0] ? null : obj.records[0];
}
user_12547070
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