This NodeJS Lambda function adds a retention policy of 14 days to any CloudWatch log group that does not already have an existing policy. This is done as a cost-saving measure to stop you from paying for uneccessary log storage.
Of course, whether and for how long logs should be kept depends on your specific use case. The retention period is configurable by modifying a variable within the Lambda function code before deploying.
This AWS SAM project deploys a serverless function comprised of a Lambda that is triggered once every 24 hours by a CloudWatch Event to add a retention policly to CloudWatch log groups that do not alreadyt have a policy. The included CloudFormation template also creates an IAM role for the Lambda that allows the function to perform required functions.
- Clone the repository
git clone https://github.com/matwerber1/aws-lambda-set-cloudwatch-logs-retention- Within ./deploy.sh, replace YOUR_S3_BUCKET with an existing S3 bucket to use for uploading packaged template to CloudFormation.
BUCKET_NAME=_YOUR_S3_BUCKET-
OPTIONAL - within ./src/index.js, set config.debug to true to have the Lambda function output raw API responses to the function logs.
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OPTIONAL - within ./src/index.js, set config.defaultRetentionDays to your desired retention period.
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Run deploy.sh
./deploy.shThe function will automatically trigger once every 24 hours via a CloudWatch Event.
Optionally, you can manually invoke the Lambda and include a JSON payload of {overridePolicies: true} to change the retention period for all log groups, regardless of what their current policies are.
Here is an example of the output from the Lambda function: