How to get SAM template of lambda function deployed via UI?

Question

I wrote a bash script similar to this one: Download an already uploaded Lambda function

Everything is fine with all lambda functions that have been deployed via SAM template files. However, when I retrieve the deployment package of a lambda function (application) that has been deployed via the web UI of AWS, all I get is the index.js file in the deployment package of that function.

Anyway, it is possible to generate a SAM yaml file that describes the architecture of the given lambda application by selecting it over the Lambda Management Console via Actions > Export Function > Download AWS SAM file. Consequently, there should be a possibility to do this via aws-cli or is that not possible at all?

Answer 1

You can get function configuration with awscli https://docs.aws.amazon.com/cli/latest/reference/lambda/get-function-configuration.html and the response will contain a Code section with a link to the function package https://docs.aws.amazon.com/lambda/latest/dg/API_FunctionCodeLocation.html

Also, you can create a CloudFormation stack from the existing infrastructure with CloudFormer https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-using-cloudformer.html

Having a CloudFormation template you can get the resource description. https://docs.aws.amazon.com/cli/latest/reference/cloudformation/describe-stack-resources.html with the link to the function source code on S3.

See more on this in https://stackoverflow.com/a/55764927/6628583