Working with S3 buckets having no BucketName in AWS Lambda
- If your Lambda is created through CloudFormation, you can pass the bucket name using Environment variables (Environment key in SAM and CloudFormation). You can refer to the bucket name using !Ref if the bucket is in the same spec and cross stack references if using different stacks. If you use cross stack references, you won't be able to modify or delete the output value in the original stack until you remove all references to it. If you are using Ref, the Lambda will also be updated if the bucket name changes.
- If your Lambda isn't created through CloudFormation, you can use SSM parameter store as mentioned by Ervin in his comment. You can create a SSM Parameter and read it's value in your Lambda code.