Turn on and off your AWS resources using the Cloud Custodian

Automatically turn on and off your AWS EC2 instances

Cloud Custodian is an open-source tool from Capital One written in python language and comprises of many tools and scripts. It is a powerful tool that allows you to put guard rails in real-time. It is serverless (code runs as a lambda function) and no agent is required. It allows you to define your own rules. It is also referred to as a “Policy as Code”.

In this story, we will discuss how awesome is the Cloud Custodian that helps us save money. It automatically turns off the ec2 instances every night or weekend and turns them back on every morning. In the below example, we have discussed a few scenarios-

# 1 — EC2 off-hours stop

policies:
- name: csp-na-ec2-off-hours-stop
  resource: aws.ec2
  comments: |
    The policy will apply only to those EC2 instances that are 
    atleast 1 hours old and include the tag "c7n_off_hours". Tag 
    your EC2 instance with Key "c7n_off_hours" for Custodian to 
    consider it in scope for action. Value can be anything. 
    Custodian just look for "Key" to consider it into the scope for 
    offhours. Stop EC2 instances as per schedule in c7n_off_hours 
    that is 0 UTC = 6PM CST.
  filters:
    - "tag:c7n_do_not_shut_down": absent
    …