AWS Classroom Notes – 11/08/2021

Boto3

• This is AWS SDK for python
• To install this pip install boto3
• Documentation of boto3 Refer Here
• Sample python code to list all the s3 buckets

import boto3

def print_s3_buckets():
    """This method will print all the s3 buckets
    """
    s3 = boto3.resource('s3')
    for bucket in s3.buckets.all():
        print(bucket.name)


if __name__ == '__main__':
    print_s3_buckets()

• Now lets try to create an lambda function which does the samething.

  • Created a lamdba function with code

  import json
  import boto3
  
  def lambda_handler(event, context):
      s3_buckets = list_s3_buckets()
      response_dict = dict()
      response_dict['buckets'] = s3_buckets
      response_dict['count'] = len(s3_buckets)
      
      
      return {
          'statusCode': 200,
          'body': json.dumps(response_dict)
      }
      
  def list_s3_buckets():
      """This method will print all the s3 buckets
      """
      s3 = boto3.resource('s3')
      s3_list = []
      for bucket in s3.buckets.all():
          s3_list.append(bucket.name)
      return s3_list
  
  

  • When i executed this lambda function using test method i got the following response

• Exercise: Lets create two ec2 instances

  • instance-1: Tag: Name: web1
  • instance-2: Tag: Name: web2

• Code in python

import boto3

def get_ec2_instance_id(key='Name', value='Web1'):
    ec2 = boto3.client('ec2')
    response = ec2.describe_instances(Filters = [
        {
            'Name': f'tag:{key}',
            'Values': [
                value,
            ]
        }])
    #print(response)
    instance_id = response['Reservations'][0]['Instances'][0]['InstanceId']
    return instance_id

def stop_ec2(instance_id):
    ec2 = boto3.client('ec2')
    try:
        ec2.stop_instances(InstanceIds=[instance_id])
    except Exception as e:
        print(e)


if __name__ == '__main__':
    instance_id=get_ec2_instance_id(value='Web1')
    stop_ec2(instance_id)