Deploying a Lambda

Breaking down what AWS SAM does

Published: Tuesday, Oct 10, 2023 Last modified: Monday, Dec 9, 2024

AWS SAM has a guided deployment mode, which is also triggered by --resolve-s3, which abstracts:

  1. sam build
  2. sam package
  3. sam deploy

sam sync also effectively does the same as the above.

sam build

sam build parses the template.yaml, builds the code and creates a .aws-sam directory with the artifacts and exports template.yaml.

sam package

sam package takes the template.yaml and uploads the artifacts to S3 into a zip file.

sam deploy

sam deploy takes the template.yaml and creates a CloudFormation stack. It also replaces the CodeUri with the S3 location.