AWS Lambda function failing to access MySQL Database from an EC2 Instance : SequelizeConnectionError connect ETIMEDOUT

Question

I am trying to access the MySQL database installed in an EC2 instance. I have written a simple AWS Lambda function in express js. The lambda function needs to access the MySQL. I am getting the below everyone when it is trying to establish the DB connection on EC2:

{
    "errorType": "SequelizeConnectionError",
    "errorMessage": "connect ETIMEDOUT",
    "name": "SequelizeConnectionError",
    "parent": {
        "errorType": "Error",
        "errorMessage": "connect ETIMEDOUT",
        "code": "ETIMEDOUT",
        "errorno": "ETIMEDOUT",
        "syscall": "connect",
        "fatal": true,
        "stack": [
            "Error: connect ETIMEDOUT",
            "    at Connection._handleTimeoutError (/var/task/node_modules/mysql2/lib/connection.js:173:17)",
            "    at ontimeout (timers.js:436:11)",
            "    at tryOnTimeout (timers.js:300:5)",
            "    at listOnTimeout (timers.js:263:5)",
            "    at Timer.processTimers (timers.js:223:10)"
        ]
    },
    "original": {
        "errorType": "Error",
        "errorMessage": "connect ETIMEDOUT",
        "code": "ETIMEDOUT",
        "errorno": "ETIMEDOUT",
        "syscall": "connect",
        "fatal": true,
        "stack": [
            "Error: connect ETIMEDOUT",
            "    at Connection._handleTimeoutError (/var/task/node_modules/mysql2/lib/connection.js:173:17)",
            "    at ontimeout (timers.js:436:11)",
            "    at tryOnTimeout (timers.js:300:5)",
            "    at listOnTimeout (timers.js:263:5)",
            "    at Timer.processTimers (timers.js:223:10)"
        ]
    },
    "stack": [
        "SequelizeConnectionError: connect ETIMEDOUT",
        "    at Utils.Promise.tap.then.catch.err (/var/task/node_modules/sequelize/lib/dialects/mysql/connection-manager.js:149:19)",
        "    at tryCatcher (/var/task/node_modules/bluebird/js/release/util.js:16:23)",
        "    at Promise._settlePromiseFromHandler (/var/task/node_modules/bluebird/js/release/promise.js:512:31)",
        "    at Promise._settlePromise (/var/task/node_modules/bluebird/js/release/promise.js:569:18)",
        "    at Promise._settlePromise0 (/var/task/node_modules/bluebird/js/release/promise.js:614:10)",
        "    at Promise._settlePromises (/var/task/node_modules/bluebird/js/release/promise.js:689:18)",
        "    at Async._drainQueue (/var/task/node_modules/bluebird/js/release/async.js:133:16)",
        "    at Async._drainQueues (/var/task/node_modules/bluebird/js/release/async.js:143:10)",
        "    at Immediate.Async.drainQueues [as _onImmediate] (/var/task/node_modules/bluebird/js/release/async.js:17:14)",
        "    at runCallback (timers.js:705:18)",
        "    at tryOnImmediate (timers.js:676:5)",
        "    at processImmediate (timers.js:658:5)"
    ]
}

The ec2 configurations are:-

Inbound Rules:

Outbound Rules

Lambda function

NOTE: vpc, subnet, and security group are same in EC2 and lambda

Here is my code:- Lambda Function Code

Any help is highly appreciated!

Answer 1

If you want to connect from lambda function to ec2 instance.

Firstly, Ec2 instances and lambda function are being in the same VPC, and

Secondly, you have to create NAT gateway for lambda function. And subnet of EC2 instance and subnet of lambda function should be routed via the same NAT gateway.

For example :