cfn-find-ami

cfn-find-ami

AWS Lambda function to find AMIs, to be used as a custom resource in CloudFormation templates.

Install the lambda function

Create an IAM policy using the find-ami-lambda-policy.json file. Create an IAM role for the lambda function using the above policy; name this role "find-ami-lambda-role".

Then run the following commands in a bash shell, where "123456789012" is your AWS account ID:

$ ./package.sh
$ aws --profile YOUR_PROFILE lambda create-function \
    --function-name find-ami --memory 128 --timeout 30 \
    --role arn:aws:iam::123456789012:role/find-ami-lambda-role \
    --runtime python3.7 --zip-file fileb://./find-ami.zip \
    --handler find-ami.handler

"Call" the lambda function from a CloudFormation template

Checkout the test-cfn-find-ami.yml file for an example.

The following Properties can be set in the custom resource:

• ServiceToken: Set to the ARN of the above lambda function
• Region: The region you want to search AMIs in; this property is mandatory
• Debug: Set to true to increase verbosity (the logs from the lambda functions are available in the CloudWatch logs)
• Architecture: The architecture to filter; mostly likely you should set this to x86_64
• Name: Filter on the AMI names; you can use * as wildcards; for example, *bionic* will search for images with "bionic" anywhere in their names
• OwnerId: Filter on the owner id
• RootDeviceType: Filter on the root device type; can be "ebs" or "instance-store"; if not set, this defaults to "ebs"
• VirtualizationType: Filter on the virtualization type; can be "hvm" or "paravirtual"; if not set, this defaults to "hvm"

The Lambda function will filter AMIs that match the parameters you provided, and will return the most recent image. The following output parameters are available:

• Id: The AMI id of the found AMI
• Name: The name of the found AMI
• Description: The description of the found AMI