CICD for Lambda

AWS SAM (Serverless Application Model) combined with CodeDeploy is one of the best and quickest approaches for Lambda development and deployment because it provides the best balance of:

• Speed of development

• Built-in testing capabilities

• Safe deployment practices

• Automated rollback mechanisms

The pre-traffic and post-traffic tests are particularly valuable as they help catch issues before they impact users, and the gradual traffic shifting minimizes risk during deployments.

1. AWS SAM offers several key advantages:

   • Simple template syntax specifically designed for serverless applications

   • Local testing capabilities through sam local

   • Built-in support for safe deployments through CodeDeploy integration

   • Integrated testing and monitoring

Your suggested approach using AWS SAM with CodeDeploy is particularly strong because:

• Traffic shifting with CodeDeploy provides automated canary deployments

• Pre/post-traffic test functions help catch issues before full deployment

• CloudWatch alarm integration enables automatic rollbacks if problems occur

• The entire process can be automated and integrated into CI/CD pipelines

However, there are a few other approaches worth considering:

1. AWS CDK (Cloud Development Kit):

   • Offers more programmatic control using familiar languages like TypeScript/Python

   • Better for complex infrastructure where you need more flexibility

   • Can still use SAM locally for testing

2. Terraform with Lambda:

   • Good choice if you're already using Terraform for other infrastructure

   • Provides consistent infrastructure-as-code across all cloud resources

3. Direct CLI deployment:

   • Quickest for simple functions and prototyping

   • Less suitable for production environments