serverless-stack-policy-by-resource-type

Serverless Framework plugin for automatically populating CloudFormation stack policy statements by resource type.

CloudFormation stack policies allow you to protect a resource from being accidentally replaced or deleted. However, it is easy to forget to update the stack policy when adding new resources that should be protected. This plugin accepts a list of resource types and automatically updates the stack policy upon new resources of that type.

For example, if all DynamoDB tables should be protected from replacement or deleted, you simply have to add

ResourceType:
  - AWS::DynamoDB::Table

to your stack policy statement.

Usage

Install the plugin:

npm install -D serverless-stack-policy-by-resource-type

Register the plugin in serverless.yml:

plugins:
  - serverless-stack-policy-by-resource-type

The following example will prevent CloudFormation from replacing or deleting the DDBTable resource or any S3 buckets except for the LoggingBucket S3 bucket:

provider:
  ...
  stackPolicy:
    - Effect: Allow
      Principal: '*'
      Action: 'Update:*'
      Resource: '*'
    - Effect: Deny
      Principal: '*'
      Action:
        - Update:Replace
        - Update:Delete

      # These resources are included in the stack policy statement.
      Resource:
        - LogicalResourceId/DDBTable

      # These resource types are parsed by this plugin
      # and converted to additional entries in `Resource`.
      ResourceType:
        - AWS::S3::Bucket

      # These resources are excluded from `Resource` after all resources by type are added.
      # This property allows you to intentionally remove a resource.
      ExcludeResource:
        - LogicalResourceId/LoggingBucket

      # Any resources matching this prefix are excluded from `Resource` after all resources by type are added.
      # This property allows you to intentionally remove a collection of resources which share the same prefix.
      ExcludeResourcePrefix:
        - LogicalResourceId/Logging