AWS CLI Configuration Variables

Configuration values for the AWS CLI can come from several sources:

       o As a command line option

       o As an environment variable

       o As a value in the AWS CLI config file

       o As a value in the AWS Shared Credential file

       Some  options  are  only available  in the AWS CLI config.  This topic
       guide covers all the configuration variables available in the AWS CLI.

       Note that if you are just looking to get the minimum required  configu-
       ration  to  run the AWS CLI, we recommend running aws configure, which
       will prompt you for the necessary configuration values.

CONFIG FILE FORMAT
       The AWS CLI config file, which defaults to ~/.aws/config has the following format:

  [default]
  aws_access_key_id=foo
  aws_secret_access_key=bar
  region=us-west-2

       The  default section refers to the configuration values for the default
       profile. You can create profiles, which represent  logical  groups  of
       configuration. Profiles that aren't the default profile are specified
       by creating a section titled "profile profilename":

  [profile testing]
  aws_access_key_id=foo
  aws_secret_access_key=bar
  region=us-west-2

   Nested Values
       Some service specific configuration, discussed in  more detail below,
       has  a  single top level key, with nested sub values.  These sub values
       are denoted by indentation:

  [profile testing]
  aws_access_key_id = foo
  aws_secret_access_key = bar
  region = us-west-2
  s3 =
    max_concurrent_requests=10
    max_queue_size=1000

For more information:
$ aws help config-vars
https://docs.aws.amazon.com/cli/latest/topic/config-vars.html
https://github.com/aws/aws-cli