Delete old AMI’s by filtering with tags using boto3 and Lambda


When you are building custom AMI’s in AWS account you will need to manage them by deleting the old AMI’s and keep only few latest images. For this you can use the below python code in Lambda function. I took the below code as reference from here and modified it to delete the AMI’s by filtering the images which has only specified tags.

Filtering the images with tags is important as different teams/projects will be having their images and it avoids accidental deletion of the wrong images.

Note: Before executing this code make sure your AMI’s are tagged.

    Code explanantion:

* First import libraries datetime, boto3 and time.
* Next get the ec2 connection session using boto3.
* Assign a variable older_days and pass the value as days (all images which are older than specified days from the present date will be filtered)

* Invoke the main function lambda_handler and then
* Invoke the function get_ami_list by passing older_days as a parameter

* Function get_ami_list uses ec2 descirbe_images to get all the images details which has specified ownerid as the owner
* Next it will invoke the function get_delete_date, calculates and finds out the date which is 5 days past from the present date
* Next the images will be filtered according to the specified tag value and if the image is older then 5 days.
* Then images are further filtered if older than 5 days and deregistered by invoking function delete_ami

from datetime import datetime, timedelta, timezone
import boto3
import time

client.ec2 = boto3.client('ec2', region_name='us-east-1')

#Here all images which are older than 5 days from the present date will be filtered
older_days = 5

def lambda_handler(event, context):

def get_ami_list(older_days):
    amiNames = client.ec2.describe_images(Owners=['123456789123'])
    today_date ='%d-%m-%Y')
    print("Today's date is " + today_date)
    deldate1 = get_delete_date(older_days)
    print("AMI images which are older than " + str(deldate1) + " will be deregistered")
    for image in amiNames['Images']:
        taginfo = image['Tags']
        for tagName in taginfo:
			#Filter only the images having tag value as Proj1AMI
            if (tagName['Value'] == 'Proj1AMI'):
                ami_creation = image['CreationDate']
                imageID = image['ImageId']
                print("Image id is " + imageID)
                print("Creation date for above image is " + ami_creation)
                if (str(ami_creation) < str(get_delete_date(older_days))):
                    print("This AMI is older than " + str(older_days) + " days")

def get_delete_date(older_days):
	delete_time = - timedelta(days=older_days)
	return delete_time;

def delete_ami(imageID):
	print("Deregistering Image ID: " + imageID)

Update SSM parameter store on another AWS account using AssumeRole


In this post we are going to update the SSM parameter store in 2nd AWS account with the details from 1st AWS account. For this we will create a AWS Lambda function with python code. The python code will assume the role from another account and uses the temporarily generated STS credentials to connect and update the SSM parameter on the 2nd AWS account.

Create a Lambda function by selecting Python 2.7 and add the below code into it


import boto3
import time

ssmparam = boto3.client('ssm')

account_id = '112211221122'
account_role = 'AssumeRole-SSM'
region_Name = 'us-east-1'

AmiId = 'ami-119c8dc1172b9c8e'

def lambda_handler(event, context):
    print("Assuming role for account: " + account_id)
    credentials = assume_role(account_id,account_role)

	#Call the function to update the SSM parameter with value

def assume_role(account_id, account_role):
    sts_client = boto3.client('sts')
    role_arn = 'arn:aws:iam::' + account_id + ':role/' + account_role
    print (role_arn)

    '''Call the assume_role method of the STSConnection object and pass the role
    ARN and a role session name'''

    assuming_role = True
    assumedRoleObject = sts_client.assume_role(RoleArn=role_arn,RoleSessionName="NewAccountRole")
    print (assumedRoleObject['Credentials'])

    '''From the response that contains the assumed role, get the temporary
    credentials that can be used to make subsequent API calls'''
    return assumedRoleObject['Credentials']
def updateSSM_otherAccount(creds, region_Name, account_id):
    client1 = boto3.client('ssm',region_name=region_Name,aws_access_key_id=creds['AccessKeyId'],aws_secret_access_key=creds['SecretAccessKey'],aws_session_token=creds['SessionToken'])

    ssmparam_update = client1.put_parameter(Name='DevAMI',
            Description='the latest ami id of Dev env',
            Value=AmiId, Type='String', Overwrite=True)

Steps to configure AssumeRole

Note: Make sure to modify the account id’s in the below json policy

1. Add the inline policy to role attached to the lambda in 1st AWS account (556655665566)

    "Version": "2012-10-17",
    "Statement": [
            "Sid": "123",
            "Effect": "Allow",
            "Action": [
            "Resource": [

2. Create a role in 2nd AWS account (AssumeRole-SSM) (112211221122), edit the trust relationship and add below policy.
Attach EC2 full permissions to this role so that we will get access to SSM parameter store

    "Version": "2012-10-17",
    "Statement": [
            "Effect": "Allow",
            "Action": [
            "Resource": "arn:aws:iam::556655665566:role/lambda-ec2-role"

Golden image creation using Packer and AWS CodePipeline

Hi All, we know that Packer can be used to create Golden images for multiple platforms. Here we will use Packer to create an Golden image of Amazon Linux OS in AWS. The created images are called as AMI which appear in AWS dashboard. The image creation is necessarry in situations when we want the OS to have pre set of packages installed to support our application. The custom created AMI can be used to spin up EC2 instances when we need to build large infrastructure frequently to support the applications.

In this tutorial I will be using AWS CodeCommit, CodeBuild and create a CodePipeline with these. The CodePipeline will automatically get triggered when a commit happens to the CodeCommit repo. The pipeline will run the CodeBuild which will trigger the buildspec.yml and use the packer build command mentioned in it to build the Golden image (AMI)

I will be commiting 2 files to CodeCommit – buildspec.yml and CreateAMI.json file

Below is the content of buildspec.yml

version: 0.2

      - echo "Installing HashiCorp Packer..."
      - curl -qL -o && unzip
      - echo "Installing jq..."
      - curl -qL -o jq && chmod +x ./jq
      - echo "Validating CreateAMI.json"
      - ./packer validate CreateAMI.json
      ### HashiCorp Packer cannot currently obtain the AWS CodeBuild-assigned role and its credentials
      ### Manually capture and configure the AWS CLI to provide HashiCorp Packer with AWS credentials
      ### More info here:
      - echo "Configuring AWS credentials"
      - curl -qL -o aws_credentials.json$AWS_CONTAINER_CREDENTIALS_RELATIVE_URI > aws_credentials.json
      - aws configure set region $AWS_REGION
      - echo "AWS region set is:" $AWS_REGION
      - aws configure set aws_access_key_id `./jq -r '.AccessKeyId' aws_credentials.json`
      - aws configure set aws_secret_access_key `./jq -r '.SecretAccessKey' aws_credentials.json`
      - aws configure set aws_session_token `./jq -r '.Token' aws_credentials.json`
      - echo "Building HashiCorp Packer template, CreateAMI.json"
      - ./packer build CreateAMI.json
      - echo "HashiCorp Packer build completed on `date`"

Below is the content of CreateAMI.json

    "variables": {
        "aws_region": "{{env `AWS_REGION`}}"
  "builders": [
      "type": "amazon-ebs",
      "region": "{{user `aws_region`}}",
      "instance_type": "t2.micro",
      "source_ami": "ami-0080e4c5bc078760e",
      "ssh_username": "ec2-user",
      "ami_name": "custom-Dev1",
      "ami_description": "Amazon Linux Image OS with pre-installed packages",
      "run_tags": {
        "Name": "custom-Dev1",
	"Env": "dev",
	"Project": "DevOps"
  "provisioners": [
      "type": "shell",
      "inline": [
        "sudo yum install java python wget -y",
	"sudo yum install tomcat -y"

1. Create an AWS CodeCommit Repository and add these 2 files into it.
2. Create AWS CodeBuild project and select CodeCommit repo and master branch
3. Create CodePipeline by selecting CodeCommit repo and CodeBuild project as stages.
Screenshot from 2018-12-19 12-06-05

Screenshot from 2018-12-19 12-07-56

Screenshot from 2018-12-19 12-08-52

Skip Deploy stage and create the pipleine.

4. Select the created CodePipeline and click on Release changes which will start running the pipeline.

5. After the pipeline finishes successfully, go to the EC2 dashboard and click on AMI in left side and you should see the created Golden image.

AWS Cloudformation – cfn-init and UserData

We use AWS Cloudformation to provision resources in AWS. There are lot of examples available in internet on different use cases.
The Cloudformation scripts can be written using yaml or json language.

Using AWS CloudFormation we can automatically install, configure, and start applications on Amazon EC2 instances. Doing so enables you to easily duplicate deployments and update existing installations without connecting directly to the instance, which can save you a lot of time and effort.

For installing packages automatically on EC2 instance upon boot up we need to use cfn-init and metadata in Cloudformation.

Below is an example on how cfn-init and metadata is defined in the Cloudformation script and how they work.Understanding of this is very important if you want to have packages installed on to EC2 instance upon boot up.

The cfn-init helper script reads template metadata from the AWS::CloudFormation::Init key and acts accordingly to:
Fetch and parse metadata from AWS CloudFormation
Install packages
Write files to disk
Enable/disable and start/stop services

cfn-init does not require credentials, so you do not need to use the –access-key, –secret-key, –role, or –credential-file options.
In this case we are connecting to S3 to download the scripts. So we need to create a role which allows access to get objects in S3 bucket, and then attach this role to EC2 instance.

Put your commands and scripts to be run on EC2 instance in the commands section under AWS::CloudFormation::Init

This will be invoked in the UserData section
/opt/aws/bin/cfn-init –verbose –stack –region us-east-1 –resource Create_Instance

We also have to install cfn as give in UserData section and start cfn service before invoking the AWS::CloudFormation::Init

Note: Please use json editor to format the below code before using it.

“Resources”: {
“Create_Instance”: {
“Type”: “AWS::EC2::Instance”,
“Metadata”: {
“AWS::CloudFormation::Init”: {
“config”: {
“commands”: {
“01_mkdir_scripts”: {
“command”: “if [ ! -d \”/home/ec2-user/scripts \” ] ; then mkdir -p \”/home/ec2-user/scripts\” ; fi;”
“02_copy_scripts_from_s3”: {
“command”: “/usr/bin/aws s3 cp s3://testBucket19/installScripts /home/ec2-user/scripts –recursive”
“03_Install_java”: {
“command”: “/bin/bash -x /home/ec2-user/scripts/”,
“waitAfterCompletion”: “50”
“04_Install_Tomcat”: {
“command”: “/bin/bash -x /home/ec2-user/scripts/”,
“waitAfterCompletion”: “50”

“Properties”: {
“UserData”: {
“Fn::Base64”: {
“Fn::Join”: [
“yum install -y python-pip\n”,
“pip install awscli\n”,
“/usr/bin/easy_install –script-dir /opt/aws/bin\n”,
“cp -v /usr/lib/python2*/site-packages/aws_cfn_bootstrap*/init/redhat/cfn-hup /etc/init.d \n”,
“chmod +x /etc/init.d/cfn-hup \n”,
“/etc/init.d/cfn-hup start \n”,
“/opt/aws/bin/cfn-init –verbose –stack “,
“Ref”: “AWS::StackId”
” –resource Create_Instance –region “,
“Ref”: “AWS::Region”
“/opt/aws/bin/cfn-signal -e 0 –stack “,
“Ref”: “AWS::StackName”
” –resource Create_Instance “,
” –region “,
“Ref”: “AWS::Region”

Delete file in sub-directory of S3 using Python

Hi All,
We use boto3 libraries to connect to S3 and do actions on bucket for objects to  upload, download, copy, delete. But let’s say if you want to download a specific object which is under a sub directory in the bucket then it becomes difficult to its less known on how to do this.

Below are few python script examples on using prefix of the subdirectory with boto and boto3 libraries

Example 1: Copy a file/object which is residing in a subdiretory of Bucket1 to Bucket2

import boto
conn = boto.connect_s3()

srcBucket = conn.get_bucket('testProjBucket-1') #Source Bucket name
dstBucket = conn.get_bucket('testProjBucket-2') #Destination Bucket name


Example 2: Downloads the test.txt from bucket ‘testProjBucket-1’ to the local system path /home/ec2-user/mydownloads/
Here the downloaded file name will be as hai.txt

import boto3
s3 = boto3.resource('s3')


s3.meta.client.download_file('testProjBucket-1', prefix1, '/home/ec2-user/mydownloads/hai.txt')

Example 3: Delete a specific object from a specific sub-directory inside a bucket (Using boto libraries)

import boto
conn = boto.connect_s3(region_name='', aws_access_key_id = '', aws_secret_access_key = '')

fileName = ""

srcBucket = conn.get_bucket('testProjBucket-1')

Example 4: Delete a specific object from a specific sub-directory inside a bucket (Using boto3 libraries)

import boto3
client = boto3.client('s3', region_name='us-east-1', aws_access_key_id = '', aws_secret_access_key = '')


response = client.delete_object(

Note: There is no move command for object in boto3 library. We can only use copy command. But we can use move in the aws-cli

How to upload and run Nodejs package using AWS Lambda

Hey guys.. If you have tried using Nodejs code to run in AWS Lambda you know how painful it is to package the node modules with needed libraries to make it work in Lambda function. Yes it is difficult in begining but once you start exploring and understanding it becomes so much interesting as what all you can achieve using nodejs.

Here I will using nodejs UUID module to generate a unique id which can be used in application or in database. The AWS documentation tells that “You can create a deployment package yourself or write your code directly in the Lambda console, in which case the console creates the deployment package for you and uploads it, creating your Lambda function.” but there is no step-by-step instructions and screenshots to show how to do it. And also you won’t get much information in other blogs as I have tried exploring and ended up without proper steps. So, I like to show you here how to do.

The best way is to install nodejs and test the code on your local linux or windows environment and then package and upload the zip file to Lambda function.

Install nodejs using this command (the OS is RedHat)

curl --silent --location | sudo bash -
sudo yum -y install nodejs

You can verify the installation by checking the node version (node -v) and npm version (npm -v)


Install the UUID module using below command

npm install uuid


You will get node_modules directory under /home/ec2-user

Navigate to directory /home/ec2-user/node_modules/uuid

and zip the all the files under this
zip -r *

Go to AWS Lambda and create a function
Select nodejs



Upload the zip file to Lambda function

Next copy the below code to the “edit code inline”

exports.handler = (event, context, callback) => {
var uuid = require('uuid');

Next save and test the function by creating a event


Then you should see new random UniqueID generated every time when you test this function.


Fetch the Elastic Beanstalk environment details using python script

Hi there!!

Its been quite sometime and have been busy working on multiple technologies. Recently my lead asked me to create a python script to fetch the minimum and maximum instances count of all the Elastic beanstalk environments. It was great to work on this requirement. Below is the python script

def get_details():
	row1=['Application Name','Environment Name','Min Count','Max count']
	with open('EB-instances-count',"a") as csvDataFile:
		writer = csv.writer(csvDataFile)
		eb = boto3.client('elasticbeanstalk',"us-east-1")
		for names in NameInfo['Environments']:
			response = eb.describe_configuration_settings(
			print "Gathering count for Environment: " + env_name
			with open('EB-instances-count.csv',"a") as csvDataFile:
				writer = csv.writer(csvDataFile)
	except ClientError as e:
		if e.response['Error']['Code'] == "InvalidParameterValue":
			print env_name + " Environment not found, so skipping it"
if __name__ == '__main__':

In this I am getting the application names and environment names of Elastic beanstalk in a region and parsing through them and fetching the min and max instances count. Also after fetching the counts I am writing them to .csv (spreadsheet) file. We can run this script at any time to know the present count of instances being used. This script can be further updated/modified to fetch different information of the environments in Elastic beanstalk.

The interesting part would be to filter the required information from the response. And other thing is lets say if the environment is deleted it will take sometime to disappear from the console and we might see error as we can still get the environment name but not its settings as its already deleted right.
So in this case we have to capture the particular error the exception part and ignore it.

Note: Be careful about the indentation 🙂

Let me know for any questions. Thanks