<gh_stars>1-10
"""
-*- coding: utf-8 -*-
========================
AWS Lambda
========================
Contributor: <NAME> (<NAME>)
========================
"""

import json
import boto3
import paramiko

def lambda_handler(event, context):
    # boto3 client
    client = boto3.client('ec2')
    s3_client = boto3.client('s3')
    
    # getting instance information
    describeInstance = client.describe_instances()

    
    hostPublicIP=[]
    # fetchin public IP address of the running instances
    for i in describeInstance['Reservations']:
        for instance in i['Instances']:
            if instance["State"]["Name"] == "running":
                hostPublicIP.append(instance['PublicIpAddress'])
    
    print(hostPublicIP)
    
    # downloading pem filr from S3
    s3_client.download_file('bucket-name','file.pem', '/tmp/file.pem')

    # reading pem file and creating key object
    key = paramiko.RSAKey.from_private_key_file("/tmp/file.pem")
    # an instance of the Paramiko.SSHClient
    ssh_client = paramiko.SSHClient()
    # setting policy to connect to unknown host
    ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    host=hostPublicIP[0]
    print("Connecting to : " + host)
    # connecting to server
    ssh_client.connect(hostname=host, username="ubuntu", pkey=key)
    print("Connected to :" + host)

    # command list
    commands = [
        "ls"
        ]

    # executing list of commands within server
    for command in commands:
        print("Executing {command}")
        stdin , stdout, stderr = ssh_client.exec_command(command)
        print(stdout.read())
        print(stderr.read())

    return {
        'statusCode': 200,
        'body': json.dumps('Thanks!')
    }
