Building Applications

To build your serverless application, use the sam build command.

sam build also gathers the build artifacts of your application's dependencies, and places them in the proper format and location for subsequent steps in your workflow. You specify dependencies in a manifest file that you include in your application (such as requirements.txt for Python functions, or package.json for Nodejs functions), or by using the Layers property of a function resource. The Layers property contains a list of Lambda layer resources that the function depends on.

If your AWS Lambda function depends on packages that have natively compiled programs, use the --use-container flag. The --use-container flag locally compiles your functions in a Docker container that functions like a Lambda environment, so they are in the right format when you deploy them to the AWS Cloud.

Examples

The following sam build commands build applications.

# Build all functions and layers, and their dependencies
sam build

# Run the build process inside a Docker container that functions like a Lambda environment
sam build --use-container

# Build and run your functions locally
sam build && sam local invoke

# For more options
sam build --help