Configuring the Amazon SAM CLI - Amazon Serverless Application Model
How to create your configuration file (the samconfig file)Configure project settingsConfigure credentials and basic settings
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Configuring the Amazon SAM CLI

One of the benefits of Amazon SAM is that it optimizes a developer's time by removing repetitive taskes. Amazon SAM CLI includes a configuration file named samconfig for this purpose. By default, no configuration to the Amazon SAM CLI is needed, but you can update your configuration file to allow you to run commands with fewer parameters by allowing Amazon SAM to instead reference your customized parameters in your configuration file. The examples in the following table show how you can optimize your commands:

Original

Optimized with samconfig

sam build --cached --parallel --use-containers

sam build

sam local invoke --env-vars locals.json

sam local invoke

sam local start-api --env-vars locals.json --warm-containers EAGER

sam local start-api

The Amazon SAM CLI provides a set of commands to help developers create, develop, and deploy serverless applications. Each of these commands is configurable with optional flags based on the preferences of the application and developer. For more information, see the Amazon SAM CLI content in GitHub

The topics in this section show you how to create your Amazon SAM CLI configuration file and customize its default settings to optimize development time for your serverless application.

How to create your configuration file (the samconfig file)

The Amazon SAM CLI configuration file (filename samconfig) is a text file that typically uses the TOML structure, but can also be in YAML. When using an Amazon Quick Start Template, this file is created when you run the sam init command. You can update this file when you deploy an application using the sam deploy -\-guided command.

After the deployment is complete, the samconfig file contains a profile named default if you used the default values. When you rerun the deploy command, Amazon SAM applies the stored configuration settings from this profile.

The benefit of the samconfig file is that Amazon SAM stores configuration settings for any other commands available in addition to the deploy command. Beyond these values created at a new deploy, there are a number of attributes that you can set in the samconfig file that can simplify other aspects of the developer workflow with Amazon SAM CLI.

Configure project settings

You can specify project-specific settings, such as Amazon SAM CLI command parameter values, in a configuration file to use with the Amazon SAM CLI. For more information about this configuration file, see Amazon SAM CLI configuration file.

Using configuration files

Configuration files are structured by environment, command, and parameter value. For more information, see Configuration file basics.

To configure a new environment

  1. Specify your new environment in your configuration file.

    The following is an example of specifying a new prod environment:

    TOML
    [prod.global.parameters]
    YAML
    prod:
  global:
    parameters:

  2. Specify parameter values as key-value pairs in the parameters section of the configuration file.

    The following is an example of specifying your application’s stack name for the prod environment.

    TOML
    [prod.global.parameters]
stack_name = "prod-app"
    YAML
    prod:
  global:
    parameters:
      stack_name: prod-app

  3. Use the --config-env option to specify the environment to use.

    The following is an example:

    $ sam deploy --config-env "prod"
To configure parameter values

  1. Specify the Amazon SAM CLI command that you’d like to configure parameter values for. To configure parameter values for all Amazon SAM CLI commands, use the global identifier.

    The following is an example of specifying parameter values for the default environment’s sam deploy command:

    TOML
    [default.deploy.parameters]
confirm_changeset = true
    YAML
    default:
  deploy:
    parameters:
      confirm_changeset: true

    The following is an example of specifying parameter values for all Amazon SAM CLI commands in the default environment:

    TOML
    [default.global.parameters]
stack_name = "sam-app"
    YAML
    default:
  global:
    parameters:
      stack_name: sam-app

  2. You can also specify parameter values and modify your configuration file through the Amazon SAM CLI interactive flow.

    The following is an example of the sam deploy --guided interactive flow:

    $ sam deploy --guided

Configuring SAM deploy
======================

    Looking for config file [samconfig.toml] :  Found
    Reading default arguments  :  Success

    Setting default arguments for 'sam deploy'
    =========================================
    Stack Name [sam-app]: ENTER
    AWS Region [us-west-2]: ENTER
    #Shows you resources changes to be deployed and require a 'Y' to initiate deploy
    Confirm changes before deploy [Y/n]: n
    #SAM needs permission to be able to create roles to connect to the resources in your template
    Allow SAM CLI IAM role creation [Y/n]: ENTER
    #Preserves the state of previously provisioned resources when an operation fails
    Disable rollback [y/N]: ENTER
    HelloWorldFunction may not have authorization defined, Is this okay? [y/N]: y
    Save arguments to configuration file [Y/n]: ENTER
    SAM configuration file [samconfig.toml]: ENTER
    SAM configuration environment [default]: ENTER

For more information, see Creating and modifying configuration files.

Examples

Basic TOML example

The following is an example of a samconfig.toml configuration file:

...
version = 0.1

[default]
[default.global]
[default.global.parameters]
stack_name = "sam-app"

[default.build.parameters]
cached = true
parallel = true

[default.deploy.parameters]
capabilities = "CAPABILITY_IAM"
confirm_changeset = true
resolve_s3 = true

[default.sync.parameters]
watch = true

[default.local_start_api.parameters]
warm_containers = "EAGER"

[prod]
[prod.sync]
[prod.sync.parameters]
watch = false

Basic YAML example

The following is an example of a samconfig.yaml configuration file:

version 0.1
default:
  global:
    parameters:
      stack_name: sam-app
  build:
    parameters:
      cached: true
      parallel: true
  deploy:
    parameters:
      capabilities: CAPABILITY_IAM
      confirm_changeset: true
      resolve_s3: true
  sync:
    parameters:
      watch: true
  local_start_api:
    parameters:
      warm_containers: EAGER
prod:
  sync:
    parameters:
      watch: false

Configure credentials and basic settings

Use the Amazon Command Line Interface (Amazon CLI) to configure basic settings such as Amazon credentials, default region name, and default output format. Once configured, you can use these settings with the Amazon SAM CLI. To learn more, see the following from the Amazon Command Line Interface User Guide:

For quick setup instructions, see Step 5: Use the Amazon CLI to configure Amazon credentials.