[SOLVED] Package Lambda and common util functions through Terraform

Package Lambda and common util functions through Terraform

I have a series of lambda functions that use some common util functions specific to my environment. These lambdas are written in python, and typical folder structure looks like

 src/
     lambda_fn1_dir/filename1.py
                  /filename2.py
     lambda_fn2_dir/filenameA.py
                   /filenameB.py

     codelib/helpder_util_fn.py

I import helper_util_fn into my lambda functions and run the lambda. Function is deployed using Terraform. What's the best way to define archive_file to point to my source definition in the aws_lambda_function resource in such a way that I can also package codelib into the zip file.

I can use archive_file resource with source_path as explained here. Can I use source_dir attribute if I am more inclined to just group at the directory level. How to handle this scenario in terraform.

Solution

Yes, you can but this use case is best suited for AWS Lambda Layers: https://docs.aws.amazon.com/lambda/latest/dg/chapter-layers.html

You can create a Layer with all your helper files and package them using terraform archive_file. Then you can config your lambdas for using the same layer.