Programmatic Access

In this lesson, you will learn how to interact with the AWS Cloud programmatically using the AWS Command Line Interface (CLI). This approach provides a powerful way to manage your AWS resources through scripts and command-line operations.

Previously, we explored two methods for accessing AWS when creating an IAM user:

1. Logging in to the Management Console using a username and password.
2. Programmatic access using access keys.

For example, you can create an S3 bucket using the AWS CLI with the following command:

aws s3api create-bucket --bucket my-bucket --region us-east-1

The AWS CLI is an open-source tool that enables you to interact with AWS services from various command-line environments, including Linux shells, command-line prompts, and PowerShell on Windows. Currently, the AWS CLI is in its second major version and can be installed on all major operating systems. Detailed instructions for downloading, installing, and configuring the AWS CLI are provided in the sections below.

Installing the AWS CLI

Installing the AWS CLI is straightforward regardless of your operating system. You can either download the package via a graphical interface or use the command line.

For Linux users, run the following commands:

$ curl "https://awscli.amazonaws.com/awscli-exe-linux_x86_64-2.0.30.zip" -o "awscliv2.zip"
$ unzip awscliv2.zip
$ sudo ./aws/install

After the installation, verify the version specific to your operating system using:

$ aws --version
aws-cli/2.0.47 Python/3.7.4 Linux/4.14.133-113.105.amzn2.x86_64 botocore/2.0.0

C:\> aws --version
aws-cli/2.0.47 Python/3.7.4 Windows/10 botocore/2.0.0

$ aws --version
aws-cli/2.0.47 Python/3.7.4 Darwin/18.7.0 botocore/2.0.0

Once downloaded, run or launch the installer on your platform and follow the on-screen instructions.

Configuring the AWS CLI

After installation, you must configure the AWS CLI with your AWS account credentials. The configuration process includes providing your:

• AWS Access Key ID
• AWS Secret Access Key
• Default region for your resources
• Preferred output format (e.g., JSON, YAML, text, or table)

Initiate the configuration by running:

$ aws configure
AWS Access Key ID [None]: AKIAI44QH8DHBEXAMPLE
AWS Secret Access Key [None]: je7MtGbClwBF/2Zp9Utk/h3yCo8nvbEXAMPLEKEY
Default region name [None]: us-west-2
Default output format [None]: json

The credentials and settings will be stored in the hidden .aws directory in your home folder. You can review your configuration files with the following commands:

$ cat ~/.aws/config
[default]
region = us-west-2
output = text

$ cat ~/.aws/credentials
[default]
aws_access_key_id = AKIAI44QH8DHBEXAMPLE
aws_secret_access_key = je7MtGbClwBF/2Zp9Utk/h3yCo8nvbEXAMPLEKEY

Using the AWS CLI

The AWS CLI follows a standard command syntax:

Base Command → Service Name → Sub-Command → Options/Parameters

For instance, to create an IAM user named Lucy, execute:

$ aws iam create-user --user-name lucy

This command utilizes the IAM service with the create-user sub-command, specifying the username lucy. The output will include details such as the username, creation date, user ID, and the ARN (Amazon Resource Name) that uniquely identifies the user:

$ aws iam create-user --user-name lucy
{
    "User": {
        "UserName": "lucy",
        "Tags": [],
        "CreateDate": "2020-09-15T23:40:11.168Z",
        "UserId": "h9r2sc5br8ss7uzhs2qm",
        "Path": "/",
        "Arn": "arn:aws:iam::000000000000:user/lucy"
    }
}

You can similarly create and manage other AWS resources using the CLI.

Accessing Help

The AWS CLI offers extensive help to guide you through commands, sub-commands, and options. To access the general help documentation, run:

$ aws help

For service-specific help, such as for IAM, execute:

$ aws iam help

To get detailed assistance with a specific sub-command (e.g., create-user), append help to the command:

$ aws iam create-user help

This will display comprehensive documentation on the command's usage and available parameters.

This concludes the lesson. You are now ready to practice using the AWS CLI in your labs and further explore the extensive capabilities of the AWS Cloud.

For additional AWS resources and documentation, visit the following links:

• AWS Documentation
• AWS CLI Official Guide
• AWS IAM Documentation