:title: AWS CLI Configuration Variables
:description: Configuration Variables for the AWS CLI
:category: General
:related command: configure, configure get, configure set
:related topic: s3-config

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

* As a command line option
* As an environment variable
* As a value in the AWS CLI config file
* 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 configuration 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


General Options
===============

The AWS CLI has a few general options:

==================== =========== ===================== ===================== ============================
Variable             Option      Config Entry          Environment Variable  Description
==================== =========== ===================== ===================== ============================
profile              --profile   N/A                   AWS_PROFILE           Default profile name
-------------------- ----------- --------------------- --------------------- ----------------------------
region               --region    region                AWS_DEFAULT_REGION    Default AWS Region
-------------------- ----------- --------------------- --------------------- ----------------------------
output               --output    output                AWS_DEFAULT_OUTPUT    Default output style
-------------------- ----------- --------------------- --------------------- ----------------------------
cli_timestamp_format N/A         cli_timestamp_format  N/A                   Output format of timestamps
-------------------- ----------- --------------------- --------------------- ----------------------------
cli_follow_urlparam  N/A         cli_follow_urlparam   N/A                   Fetch URL url parameters
-------------------- ----------- --------------------- --------------------- ----------------------------
ca_bundle            --ca-bundle ca_bundle             AWS_CA_BUNDLE         CA Certificate Bundle
-------------------- ----------- --------------------- --------------------- ----------------------------
parameter_validation N/A         parameter_validation  N/A                   Toggles parameter validation
-------------------- ----------- --------------------- --------------------- ----------------------------
tcp_keepalive        N/A         tcp_keepalive         N/A                   Toggles TCP Keep-Alive
==================== =========== ===================== ===================== ============================

The third column, Config Entry, is the value you would specify in the AWS CLI
config file.  By default, this location is ``~/.aws/config``.  If you need to
change this value, you can set the ``AWS_CONFIG_FILE`` environment variable
to change this location.

The valid values of the ``output`` configuration variable are:

* json
* table
* text

``cli_timestamp_format`` controls the format of timestamps displayed by the AWS CLI.
The valid values of the ``cli_timestamp_format`` configuration variable are:

* none - Display the timestamp exactly as received from the HTTP response.
* iso8601 - Reformat timestamp using iso8601 in the UTC timezone.

``cli_follow_urlparam`` controls whether or not the CLI will attempt to follow
URL links in parameters that start with either prefix ``https://`` or
``http://``.  The valid values of the ``cli_follow_urlparam`` configuration
variable are:

* true - This is the default value. With this configured the CLI will follow
  any string parameters that start with ``https://`` or ``http://`` will be
  fetched, and the downloaded content will be used as the parameter instead.
* false - The CLI will not treat strings prefixed with ``https://`` or
  ``http://`` any differently than normal string parameters.

``parameter_validation`` controls whether parameter validation should occur
when serializing requests. The default is True. You can disable parameter
validation for performance reasons. Otherwise, it's recommended to leave
parameter validation enabled.

When you specify a profile, either using ``--profile profile-name`` or by
setting a value for the ``AWS_PROFILE`` environment variable, profile
name you provide is used to find the corresponding section in the AWS CLI
config file.  For example, specifying ``--profile development`` will instruct
the AWS CLI to look for a section in the AWS CLI config file of
``[profile development]``.

Precedence
----------

The above configuration values have the following precedence:

* Command line options
* Environment variables
* Configuration file


Credentials
===========

Credentials can be specified in several ways:

* Environment variables
* The AWS Shared Credential File
* The AWS CLI config file

============================= ============================= ================================= ==============================
Variable                      Creds/Config Entry            Environment Variable              Description
============================= ============================= ================================= ==============================
access_key                    aws_access_key_id             AWS_ACCESS_KEY_ID                 AWS Access Key
----------------------------- ----------------------------- --------------------------------- ------------------------------
secret_key                    aws_secret_access_key         AWS_SECRET_ACCESS_KEY             AWS Secret Key
----------------------------- ----------------------------- --------------------------------- ------------------------------
token                         aws_session_token             AWS_SESSION_TOKEN                 AWS Token (temp credentials)
----------------------------- ----------------------------- --------------------------------- ------------------------------
metadata_service_timeout      metadata_service_timeout      AWS_METADATA_SERVICE_TIMEOUT      EC2 metadata creds timeout
----------------------------- ----------------------------- --------------------------------- ------------------------------
metadata_service_num_attempts metadata_service_num_attempts AWS_METADATA_SERVICE_NUM_ATTEMPTS EC2 metadata creds retry count
============================= ============================= ================================= ==============================

The second column specifies the name that you can specify in either the AWS CLI
config file or the AWS Shared credentials file (``~/.aws/credentials``).


The Shared Credentials File
---------------------------

The shared credentials file has a default location of
``~/.aws/credentials``.  You can change the location of the shared
credentials file by setting the ``AWS_SHARED_CREDENTIALS_FILE``
environment variable.

This file is an INI formatted file with section names
corresponding to profiles.  With each section, the three configuration
variables shown above can be specified: ``aws_access_key_id``,
``aws_secret_access_key``, ``aws_session_token``.  **These are the only
supported values in the shared credential file.**  Also note that the
section names are different than the AWS CLI config file (``~/.aws/config``).
In the AWS CLI config file, you create a new profile by creating a section of
``[profile profile-name]``, for example::

    [profile development]
    aws_access_key_id=foo
    aws_secret_access_key=bar

In the shared credentials file, profiles are not prefixed with ``profile``,
for example::

    [development]
    aws_access_key_id=foo
    aws_secret_access_key=bar


Precedence
----------

Credentials from environment variables have precedence over credentials from
the shared credentials and AWS CLI config file.  Credentials specified in the
shared credentials file have precedence over credentials in the AWS CLI config
file. If ``AWS_PROFILE`` environment variable is set and the
``AWS_ACCESS_KEY_ID`` and ``AWS_SECRET_ACCESS_KEY`` environment variables are
set, then the credentials provided by  ``AWS_ACCESS_KEY_ID`` and
``AWS_SECRET_ACCESS_KEY`` will override the credentials located in the
profile provided by ``AWS_PROFILE``.


Using AWS IAM Roles
-------------------

If you are on an Amazon EC2 instance that was launched with an IAM role, the
AWS CLI will automatically retrieve credentials for you.  You do not need
to configure any credentials.

Additionally, you can specify a role for the AWS CLI to assume, and the AWS
CLI will automatically make the corresponding ``AssumeRole`` calls for you.
Note that configuration variables for using IAM roles can only be in the AWS
CLI config file.

You can specify the following configuration values for configuring an IAM role
in the AWS CLI config file:

* ``role_arn`` - The ARN of the role you want to assume.
* ``source_profile`` - The AWS CLI profile that contains credentials /
  configuration the CLI should use for the initial ``assume-role`` call. This
  profile may be another profile configured to use ``assume-role``, though
  if static credentials are present in the profile they will take precedence.
  This parameter cannot be provided alongside ``credential_source``.
* ``credential_source`` - The credential provider to use to get credentials for
  the initial ``assume-role`` call. This parameter cannot be provided
  alongside ``source_profile``. Valid values are:

  * ``Environment`` to pull source credentials from environment variables.
  * ``Ec2InstanceMetadata`` to use the EC2 instance role as source credentials.
  * ``EcsContainer`` to use the ECS container credentials as the source
    credentials.

* ``external_id`` - A unique identifier that is used by third parties to assume
  a role in their customers' accounts.  This maps to the ``ExternalId``
  parameter in the ``AssumeRole`` operation.  This is an optional parameter.
* ``mfa_serial`` - The identification number of the MFA device to use when
  assuming a role.  This is an optional parameter.  Specify this value if the
  trust policy of the role being assumed includes a condition that requires MFA
  authentication. The value is either the serial number for a hardware device
  (such as GAHT12345678) or an Amazon Resource Name (ARN) for a virtual device
  (such as arn:aws:iam::123456789012:mfa/user).
* ``role_session_name`` - The name applied to this assume-role session. This
  value affects the assumed role user ARN  (such as
  arn:aws:sts::123456789012:assumed-role/role_name/role_session_name). This
  maps to the ``RoleSessionName`` parameter in the ``AssumeRole`` operation.
  This is an optional parameter.  If you do not provide this value, a
  session name will be automatically generated.
* ``duration_seconds`` - The  duration,  in seconds, of the role session.
  The value can range from 900 seconds (15 minutes) up to  the  maximum 
  session  duration setting  for  the role.  This is an optional parameter
  and by default, the value is set to 3600 seconds.

If you do not have MFA authentication required, then you only need to specify a
``role_arn`` and either a ``source_profile`` or a ``credential_source``.

When you specify a profile that has IAM role configuration, the AWS CLI
will make an ``AssumeRole`` call to retrieve temporary credentials.  These
credentials are then stored (in ``~/.aws/cli/cache``).  Subsequent AWS CLI
commands will use the cached temporary credentials until they expire, in which
case the AWS CLI will automatically refresh credentials.

If you specify an ``mfa_serial``, then the first time an ``AssumeRole`` call is
made, you will be prompted to enter the MFA code.  Subsequent commands will use
the cached temporary credentials.  However, when the temporary credentials
expire, you will be re-prompted for another MFA code.


Example configuration using ``source_profile``::

  # In ~/.aws/credentials:
  [development]
  aws_access_key_id=foo
  aws_secret_access_key=bar

  # In ~/.aws/config
  [profile crossaccount]
  role_arn=arn:aws:iam:...
  source_profile=development

Example configuration using ``credential_source`` to use the instance role as
the source credentials for the assume role call::

  # In ~/.aws/config
  [profile crossaccount]
  role_arn=arn:aws:iam:...
  credential_source=Ec2InstanceMetadata


Sourcing Credentials From External Processes
--------------------------------------------

.. warning::

    The following describes a method of sourcing credentials from an external
    process. This can potentially be dangerous, so proceed with caution. Other
    credential providers should be preferred if at all possible. If using
    this option, you should make sure that the config file is as locked down
    as possible using security best practices for your operating system.

If you have a method of sourcing credentials that isn't built in to the AWS
CLI, you can integrate it by using ``credential_process`` in the config file.
The AWS CLI will call that command exactly as given and then read json data
from stdout. The process must write credentials to stdout in the following
format::

    {
      "Version": 1,
      "AccessKeyId": "",
      "SecretAccessKey": "",
      "SessionToken": "",
      "Expiration": ""
    }

The ``Version`` key must be set to ``1``. This value may be bumped over time
as the payload structure evolves.

The ``Expiration`` key is an ISO8601 formatted timestamp. If the ``Expiration``
key is not returned in stdout, the credentials are long term credentials that
do not refresh. Otherwise the credentials are considered refreshable
credentials and will be refreshed automatically. NOTE: Unlike with assume role
credentials, the AWS CLI will NOT cache process credentials. If caching is
needed, it must be implemented in the external process.

The process can return a non-zero RC to indicate that an error occurred while
retrieving credentials.

Some process providers may need additional information in order to retrieve the
appropriate credentials. This can be done via command line arguments. NOTE:
command line options may be visible to process running on the same machine.

Example configuration::

    [profile dev]
    credential_process = /opt/bin/awscreds-custom

Example configuration with parameters::

    [profile dev]
    credential_process = /opt/bin/awscreds-custom --username monty


Service Specific Configuration
==============================

API Versions
------------

The API version to use for a service can be set using the ``api_versions``
key. To specify an API version, set the API version to the name of the service
as a sub value for ``api_versions``.

Example configuration::

    [profile development]
    aws_access_key_id=foo
    aws_secret_access_key=bar
    api_versions =
        ec2 = 2015-03-01
        cloudfront = 2015-09-17

By setting an API version for a service, it ensures that the interface for
that service's commands is representative of the specified API version.

In the example configuration, the ``ec2`` CLI commands will be representative
of Amazon EC2's ``2015-03-01`` API version and the ``cloudfront`` CLI commands
will be representative of Amazon CloudFront's ``2015-09-17`` API version.


Amazon S3
---------

There are a number of configuration variables specific to the S3 commands. See
:doc:`s3-config` (``aws help topics s3-config``) for more details.


OS Specific Configuration
=========================

Locale
------

If you have data stored in AWS that uses a particular encoding, you should make
sure that your systems are configured to accept that encoding. For instance, if
you have unicode characters as part of a key on EC2 you will need to make sure
that your locale is set to a unicode-compatible locale. How you configure your
locale will depend on your operating system and your specific IT requirements.
One option for UNIX systems is the ``LC_ALL`` environment variable. Setting
``LC_ALL=en_US.UTF-8``, for instance, would give you a United States English
locale which is compatible with unicode.
