Cloud Custodian Overview

Overview

Cloud Custodian is an open-source tool designed to manage and automate cloud resources. It allows users to define policies for governance, security, and cost management in their cloud environments. These policies can be used to automatically take actions like shutting down unused resources, enforcing tagging standards, or monitoring compliance with organizational policies.

Problems Addressed

Cloud Custodian helps users address several key challenges in cloud environments:

Governance and Compliance: Ensures that cloud resources comply with organizational policies and regulatory requirements. Cost Management: Identifies and manages unused or underutilized resources to optimize costs. Security: Automates security best practices, such as ensuring resources are encrypted and properly configured. Operational Efficiency: Reduces manual intervention by automating routine tasks and resource management.

Getting Started with Cloud Custodian

Here’s a brief demo on how to get started with Cloud Custodian and use it in a scenario:

Step 1: Installation First, install Cloud Custodian using pip:

pip install c7n

Verify the installation by running:

custodian version

Step 2: Writing a Policy

Create a policy to shut down unused EC2 instances. Save the following YAML content into a file named stop-unused-ec2.yml:

policies:
  - 
  name: stop-unused-ec2
    resource: ec2
    filters:
      - State.Name: running
      - type: unused
        days: 30
    actions:
      - stop

This policy does the following:

• Targets EC2 instances.
• Filters for instances that have been running and unused for 30 days.
• Stops those instances.

Step 3: Running the Policy Execute the policy with the following command:

custodian run -s . stop-unused-ec2.yml

This command will:

• Run the stop-unused-ec2 policy.
• Output results to the current directory (-s .).

Step 4: Checking the Results Cloud Custodian will generate output files that show which resources were affected. Review these files to ensure the policy worked as expected.

Scenario: Enforcing Tagging Standards Another common use case for Cloud Custodian is enforcing tagging standards. Here’s an example policy that ensures all EC2 instances have the Environment tag set to either dev, staging, or prod.

Create a policy file named tag-compliance.yml:

policies:
  - name: tag-compliance
    resource: ec2
    filters:
      - "tag:Environment": absent
    actions:
      - type: mark-for-op
        op: terminate
        days: 7
        tag: "custodian_cleanup"

This policy:

• Targets EC2 instances.
• Filters for instances without the Environment tag.
• Marks the instances for termination in 7 days if the tag is not added.

Run the policy:

custodian run -s . tag-compliance.yml

Review the results and take appropriate action based on the findings.

If you would like to see me walking through this demo then this session does just that. I will try and record demos for each of these.