AL2 on Amazon EC2 - Amazon Linux 2
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AL2 on Amazon EC2

Note

AL2 is no longer the current version of Amazon Linux. AL2023 is the successor to AL2. For more information, see Comparing AL2 and AL2023 and the list of Package changes in AL2023 in the AL2023 User Guide.

Launch Amazon EC2 instance with AL2 AMI

You can launch an Amazon EC2 instance with the AL2 AMI. For more information, see Step 1: Launch an instance.

Connecting to an Amazon EC2 instance

There are several ways to connect to your Amazon Linux instance, including SSH, Amazon Systems Manager Session Manager, and EC2 Instance Connect. For more information, see Connect to your Linux instance in the Amazon EC2 User Guide for Linux Instances.

SSH users and sudo

Amazon Linux does not allow remote root secure shell (SSH) by default. Also, password authentication is disabled to prevent brute force attacks. To enable SSH logins to an Amazon Linux instance, you must provide your key pair to the instance at launch. You must also set the security group used to launch your instance to allow SSH access. By default, the only account that can log in remotely using SSH is ec2-user. This account also has sudo privileges. If you enable remote root login, be aware that it is less secure than relying on key pairs and a secondary user.

AL2 AMI boot mode

AL2 AMIs don't have a boot mode parameter set. Instances launched from AL2 AMIs follow the default boot mode value of the instance type. For more information, see Boot modes in the Amazon EC2 User Guide for Linux Instances.

Package repository

This information applies to AL2 and AL1. For information about AL2023, see Managing packages and operating system updates in the AL2023 User Guide.

AL2 and AL1 are designed to be used with online package repositories hosted in each Amazon EC2 Amazon Region. The repositories are available in all Regions and are accessed using yum update tools. Hosting repositories in each Region enables us to deploy updates quickly and without any data transfer charges.

Important

The last version of AL1 reached EOL on December 31, 2023 and will not receive any security updates or bug fixes starting January 1, 2024. For more information, see Amazon Linux AMI end-of-life.

If you don't need to preserve data or customizations for your instances, you can launch new instances using the current AL2 AMI. If you do need to preserve data or customizations for your instances, you can maintain those instances through the Amazon Linux package repositories. These repositories contain all the updated packages. You can choose to apply these updates to your running instances. Earlier versions of the AMI and update packages continue to be available for use, even as new versions are released.

Note

To update and install packages without internet access on an Amazon EC2 instance, see How can I update yum or install packages without internet access on my Amazon EC2 instances running AL1, AL2, or AL2023?

To install packages, use the following command:

[ec2-user ~]$ sudo yum install package

If you find that Amazon Linux doesn't contain an application that you need, you can install the application directly on your Amazon Linux instance. Amazon Linux uses RPMs and yum for package management, and that is likely the most direct way to install new applications. You should check to see if an application is available in our central Amazon Linux repository first, because many applications are available there. From there, you can add these applications to your Amazon Linux instance.

To upload your applications onto a running Amazon Linux instance, use scp or sftp and then configure the application by logging in to your instance. Your applications can also be uploaded during the instance launch by using the PACKAGE_SETUP action from the built-in cloud-init package. For more information, see Using cloud-init on AL2.

Security updates

Security updates are provided using the package repositories. Both security updates and updated AMI security alerts are published in the Amazon Linux Security Center. For more information about Amazon security policies or to report a security problem, see Amazon Cloud Security.

AL1 and AL2 are configured to download and install critical or important security updates at launch time. Kernel updates are not included in this configuration.

In AL2023, this configuration has changed compared to AL1 and AL2. For more information about security updates for AL2023, see Security updates and features in the AL2023 User Guide.

We recommend that you make the necessary updates for your use case after launch. For example, you might want to apply all updates (not just security updates) at launch, or evaluate each update and apply only the ones applicable to your system. This is controlled using the following cloud-init setting: repo_upgrade. The following snippet of cloud-init configuration shows how you can change the settings in the user data text you pass to your instance initialization:

#cloud-config repo_upgrade: security

The possible values for repo_upgrade are as follows:

critical

Apply outstanding critical security updates.

important

Apply outstanding critical and important security updates.

medium

Apply outstanding critical, important, and medium security updates.

low

Apply all outstanding security updates, including low-severity security updates.

security

Apply outstanding critical or important updates that Amazon marks as security updates.

bugfix

Apply updates that Amazon marks as bug fixes. Bug fixes are a larger set of updates, which include security updates and fixes for various other minor bugs.

all

Apply all applicable available updates, regardless of their classification.

none

Don't apply any updates to the instance on start up.

The default setting for repo_upgrade is security. That is, if you don't specify a different value in your user data, by default, Amazon Linux performs the security upgrades at launch for any packages installed at that time. Amazon Linux also notifies you of any updates to the installed packages by listing the number of available updates upon login using the /etc/motd file. To install these updates, you need to run sudo yum upgrade on the instance.

Repository configuration

For AL1 and AL2, AMIs are a snapshot of the packages available at the time the AMI was created, with the exception of security updates. Any packages not on the original AMI, but installed at runtime, will be the latest version available. To get the latest packages available for AL2, run yum update -y.

For AL2023, the repository configuration has changed compared to AL1 and AL2. For more information about the AL2023 repository, see Managing packages and operating system updates.

Versions up to AL2023 were configured to deliver a continuous flow of updates to roll from one minor version of Amazon Linux to the next version, also called rolling releases. As a best practice, we recommend you update your AMI to the latest available AMI rather than launching old AMIs and applying updates.

In-place upgrades are not supported between major Amazon Linux versions, such as from AL1 to AL2 or from AL2 to AL2023. For more information, see Amazon Linux availability.