How to use .pem file inside Amazon Lambda to access EC2 instance

Question

I'm currently working on a project that take place inside the AWS environment. I have configure a S3 bucket in order to receive mails (mails are coming from SES but that's not relevant).

What I want to do is to create a Lambda function that will be able to access a EC2 instance and launch a python scripts. So far i have the code below. The problem is that when I created my ec2 instance, I didnt create any username or password to connect via SSH. I only have a .pem file (certificate file) to authenticate to the instance.

I did some research but i couldn't find anything useful.

var SSH = require('simple-ssh');
var ssh = new SSH({
    host: 'localhost',
    user: 'username',
    pass: 'password'
});

ssh.exec('python3.6 path/to/my/python/script.py', {
    out: function(stdout) {
        console.log(stdout);
    }
}).start();

i've been thinking of severals solutions, but i'm not sure at all :

• find an SSH library in Javascript that handle .pem file
• converting .pem into a String (not secure at all, in my opinion).
• maybe create a new ssh user in EC2 ?

Thanks you for your time.

Answer 1

A better option would be to use AWS Systems Manager to remotely run commands on your Amazon EC2 instances.

If you still choose to use simple-ssh then you need to supply an SSH key in config.key when creating your SSH object. You can store the private key in Parameter Store or Secrets Manager and retrieve it within the Lambda. In this case, you should definitely use passwordless SSH (with keypair).