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Cloud Custodian - Policy Rules Engine

Project description


Cloud Custodian

Cloud Custodian is a rules engine for AWS resource management. It allows users to define policies to be enforced to enable a well managed cloud, with metrics and structured outputs. It consolidates many of the adhoc scripts organizations have into a lightweight and flexible tool.

Organizations can use Custodian to manage their AWS environments by ensuring compliance to security policies, tag policies, garbage collection of unused resources, and cost management via off-hours resource management.

Custodian policies are written in simple YAML configuration files that specify given a resource type (ec2, asg, redshift, etc) and are constructed from a vocabulary of filters and actions. Custodian was created to unify the dozens of tools and scripts most organizations use for managing their AWS accounts into one open source tool and provide unified operations and reporting.

It integrates with lambda and cloudwatch events to provide for realtime enforcement of policies with builtin provisioning, or can isomorphically be used to query and operate against all of account resources.


First a policy file needs to be created in yaml format, as an example:

 - name: remediate-extant-keys
   description: |
     Scan through all s3 buckets in an account and ensure all objects
     are encrypted (default to AES256).
   resources: s3
     - encrypt-keys

 - name: ec2-require-non-public-and-encrypted-volumes
   resource: ec2
   description: |
     Provision a lambda and cloud watch event target
     that looks at all new instances not in an autoscale group
     and terminates those with unencrypted volumes.
     type: cloudtrail
      - RunInstances
     - Encrypted: false
     - terminate

 - name: tag-compliance
   resources: ec2
     Schedule a resource that does not meet tag compliance policies
     to be stopped in four days.
     - State.Name: running
     - "tag:Environment": absent
     - "tag:AppId": absent
     - or:
       - "tag:OwnerContact": absent
       - "tag:DeptID": absent
     - type: mark-for-op
       op: stop
       days: 4

Given that, you can run cloud-custodian

# Directory for outputs
$ mkdir out

# Validate the configuration
$ custodian validate -c policy.yml

# Dryrun on the policies (no actions executed)
$ custodian run --dryrun -c policy.yml -s out

# Run the policy
$ custodian run -c policy.yml -s out

Maid supports a few other useful subcommands and options, including outputs to s3, cloud watch metrics, sts role assumption.

Consult the documentation for additional information.

Get Involved

Mailing List -!forum/cloud-custodian

Irc - #cloud-custodian on

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