Migration from Amazon Linux AMI (AL1) to AL2 or AL2023 - AWS Elastic Beanstalk
Differences and compatibilityMigration processHelpful referencesConsiderations for all Linux platformsPlatform specific considerations

Migration from Amazon Linux AMI (AL1) to AL2 or AL2023

If your Elastic Beanstalk application is based on an Amazon Linux AMI platform branch, use this section to learn how to migrate your application's environments to Amazon Linux 2 or Amazon Linux 2023. Previous generation platform branches based on Amazon Linux AMI are now retired.

We highly recommend that you migrate to Amazon Linux 2023, since it's more recent than Amazon Linux 2. The Amazon Linux 2 operating system will reach end of support before Amazon Linux 2023 does, so you'll benefit from a longer time frame of support if you migrate to Amazon Linux 2023.

It's worthwhile to note that there is a high degree of compatibility between the Elastic Beanstalk Amazon Linux 2 and Amazon Linux 2023 platforms. Although some areas do have differences: the Instance Metadata Service Version 1 (IMDSv1) option default, support for the pkg-repo instance tool, and some Apache HTTPd configuration. For more information, see Amazon Linux 2023

Differences and compatibility

The AL2023/AL2 based platform branches aren't guaranteed to be backward compatible with your existing application. It's also important to be aware that even if your application code successfully deploys to the new platform version, it might behave or perform differently due to operating system and run time differences.

Although Amazon Linux AMI and AL2023/AL2 share the same Linux kernel, they differ in the following aspects: their initialization system, the libc versions, the compiler tool chain, and various packages. For more information, see Amazon Linux 2 FAQs.

The Elastic Beanstalk service has also updated platform specific versions of runtime, build tools, and other dependencies.

Therefore we recommend that you take your time, test your application thoroughly in a development environment, and make any necessary adjustments.

General migration process

When you're ready to go to production, Elastic Beanstalk requires a blue/green deployment to perform the upgrade. The following are the general best practice steps that we recommend for migration with a blue/green deployment procedure.

Preparing to test for your migration

Before you deploy your application and start testing, review the information in Considerations for all Linux platforms, which follows later in this topic. Also, review the information that applies to your platform in the Platform specific considerations section that follows. Make a note of the specific information from this content that applies or may apply to your application and configuration set up.

High level migration steps

  1. Create a new environment that's based on an AL2 or AL2023 platform branch. We recommend that you migrate to an AL2023 platform branch.

  2. Deploy your application to the target AL2023/AL2 environment.

    Your existing production environment will remain active and unaffected, while you iterate through testing and making adjustments to the new environment.

  3. Test your application thoroughly in the new environment.

  4. When your destination AL2023/AL2 environment is ready to go to production, swap the CNAMEs of the two environments to redirect traffic to the new environment.

More detailed migration steps and best practices

For a more detailed blue/green deployment procedure, see Blue/Green deployments with Elastic Beanstalk.

For more specific guidance and detailed best practice steps, see Blue/Green method.

More references to help plan your migration

The following references can offer additional information to plan your migration.

Considerations for all Linux platforms

The following table discusses considerations you should be aware of when planning an application migration to AL2023/AL2. These considerations apply to any of the Elastic Beanstalk Linux platforms, regardless of specific programming languages or application servers.

Area Changes and information

Configuration Files

On AL2023/AL2 platforms, you can use configuration files as before, and all sections work the same way. However, specific settings might not work the same as they did on previous Amazon Linux AMI platforms. For example:

  • Some software packages that you install using a configuration file might not be available on AL2023/AL2, or their names might have changed.

  • Some platform specific configuration options have moved from their platform specific namespaces to different, platform agnostic namespaces.

  • Proxy configuration files provided in the .ebextensions/nginx directory should move to the .platform/nginx platform hooks directory. For details, expand the Reverse Proxy Configuration section in Extending Elastic Beanstalk Linux platforms.

We recommend using platform hooks to run custom code on your environment instances. You can still use commands and container commands in .ebextensions configuration files, but they aren't as easy to work with. For example, writing command scripts inside a YAML file can be cumbersome and difficult to test.

You still need to use .ebextensions configuration files for any script that needs a reference to an AWS CloudFormation resource.

Platform hooks

AL2 platforms introduced a new way to extend your environment's platform by adding executable files to hook directories on the environment's instances. With previous Linux platform versions, you might have used custom platform hooks. These hooks weren't designed for managed platforms and weren't supported, but could work in useful ways in some cases. With AL2023/AL2 platform versions, custom platform hooks don't work. You should migrate any hooks to the new platform hooks. For details, expand the Platform Hooks section in Extending Elastic Beanstalk Linux platforms.

Supported proxy servers

AL2023/AL2 platform versions support the same reverse proxy servers as each platform supported in its Amazon Linux AMI platform versions. All AL2023/AL2; platform versions use nginx as their default reverse proxy server, with the exception of the ECS and Docker platforms. The Tomcat, Node.js, PHP, and Python platform also support Apache HTTPD as an alternative. All platforms enable proxy server configuration in a uniform way, as described in this section. However, configuring the proxy server is slightly different than it was on Amazon Linux AMI. These are the differences for all platforms:

  • Default is nginx – The default proxy server on all AL2023/AL2 platform versions is nginx. On Amazon Linux AMI platform versions of Tomcat, PHP, and Python, the default proxy server was Apache HTTPD.

  • Consistent namespace – All AL2023/AL2 platform versions use the aws:elasticbeanstalk:environment:proxy namespace to configure the proxy server. On Amazon Linux AMI platform versions this was a per-platform decision, and Node.js used a different namespace.

  • Configuration file location – You should place proxy configuration files in the .platform/nginx and .platform/httpd directories on all AL2023/AL2 platform versions. On Amazon Linux AMI platform versions these locations were .ebextensions/nginx and .ebextensions/httpd, respectively.

For platform-specific proxy configuration changes, see Platform specific considerations. For information about proxy configuration on AL2023/AL2 platforms, expand the Reverse Proxy Configuration section in Extending Elastic Beanstalk Linux platforms.

Proxy Configuration Changes

There are proxy configuration changes that apply uniformly to all platforms in addition to proxy configuration changes that are specific to each platform. It's important to refer to both to accurately configure your environments.

Instance profile

AL2023/AL2 platforms require an instance profile to be configured. Environment creation might temporarily succeed without one, but the environment might show errors soon after creation when actions requiring an instance profile start failing. For details, see Managing Elastic Beanstalk instance profiles.

Enhanced health

AL2023/AL2 platform versions enable enhanced health by default. This is a change if you don't use the Elastic Beanstalk console to create your environments. The console enables enhanced health by default whenever possible, regardless of platform version. For details, see Enhanced health reporting and monitoring.

Custom AMI

If your environment uses a custom AMI, create a new AMI based on AL2023/AL2 for your new environment using an Elastic Beanstalk AL2023/AL2 platform.

Custom platforms

The managed AMIs of AL2023/AL2 platform versions don't support custom platforms.

Platform specific considerations

This section discusses migration considerations specific to particular Elastic Beanstalk Linux platforms.

The Docker platform branch family based on Amazon Linux AMI (AL1) includes three platform branches. We recommend a different migration path for each.

AL1 Platform branch Migration Path to AL2023/AL2

Multi-container Docker managed by Amazon ECS running on Amazon Linux AMI (AL1)
ECS based Docker AL2023/AL2 platform branches

The ECS based Docker AL2023/AL2 platform branches offer a straightforward migration path for environments running on the Multi-container Docker AL1 platform branch.

  • Like the previous Multi-container Docker AL1 branch, the AL2023/AL2 platform branches use Amazon ECS to coordinate deployment of multiple Docker containers to an Amazon ECS cluster in an Elastic Beanstalk environment.

  • The AL2023/AL2 platform branches support all of the features in the previous Multi-container Docker AL1 branch.

  • The AL2023/AL2 platform branches also support the same Dockerrun.aws.json v2 file.

For more information about migrating your applications running on the Multi-container Docker Amazon Linux platform branch to an Amazon ECS running on AL2023/AL2 platform branch, see Migrating Multi-container Docker running on Amazon Linux to ECS on Amazon Linux 2023.

Docker running on Amazon Linux AMI (AL1)

Preconfigured Docker (Glassfish 5.0) running Amazon Linux AMI (AL1)
Docker Running on AL2023/AL2 platform branch

We recommend that you migrate your applications running on environments based on Preconfigured Docker (Glassfish 5.0) or Docker running on Amazon Linux AMI (AL1) to environments that are based on the Docker Running on Amazon Linux 2 or Docker Running on AL2023 platform branches.

If your environment is based on the Preconfigured Docker (Glassfish 5.0) platform branch, see Deploying a GlassFish application to the Docker platform: a migration path to Amazon Linux 2023.

The following table lists migration information specific to the platform branch Docker Running on AL2023/AL2.

Area Changes and information

Storage

Elastic Beanstalk configures Docker to use storage drivers to store Docker images and container data. On Amazon Linux AMI, Elastic Beanstalk used the Device Mapper storage driver. To improve performance, Elastic Beanstalk provisioned an extra Amazon EBS volume. On AL2023/AL2 Docker platform versions, Elastic Beanstalk uses the OverlayFS storage driver, and achieves even better performance while not requiring a separate volume anymore.

With Amazon Linux AMI, if you used the BlockDeviceMappings option of the aws:autoscaling:launchconfiguration namespace to add custom storage volumes to a Docker environment, we advised you to also add the /dev/xvdcz Amazon EBS volume that Elastic Beanstalk provisions. Elastic Beanstalk doesn't provision this volume anymore, so you should remove it from your configuration files. For details, see Docker configuration on Amazon Linux AMI (preceding Amazon Linux 2).

Private repository authentication

When you provide a Docker-generated authentication file to connect to a private repository, you no longer need to convert it to the older format that Amazon Linux AMI Docker platform versions required. AL2023/AL2 Docker platform versions support the new format. For details, see Using images from a private repository.

Proxy server

AL2023/AL2 Docker platform versions don't support standalone containers that don't run behind a proxy server. On Amazon Linux AMI Docker platform versions, this used to be possible through the none value of the ProxyServer option in the aws:elasticbeanstalk:environment:proxy namespace.

The following table lists migration information for the AL2023/AL2 platform versions in the Go platform.

Area Changes and information

Port passing

On AL2023/AL2 platforms, Elastic Beanstalk doesn't pass a port value to your application process through the PORT environment variable. You can simulate this behavior for your process by configuring a PORT environment property yourself. However, if you have multiple processes, and you're counting on Elastic Beanstalk passing incremental port values to your processes (5000, 5100, 5200 etc.), you should modify your implementation. For details, expand the Reverse proxy configuration section in Extending Elastic Beanstalk Linux platforms.

The following table lists migration information for the Corretto platform branches in the Java SE platform.

Area Changes and information

Corretto vs. OpenJDK

To implement the Java Platform, Standard Edition (Java SE), AL2023/AL2 platform branches use Amazon Corretto, an AWS distribution of the Open Java Development Kit (OpenJDK). Prior Elastic Beanstalk Java SE platform branches use the OpenJDK packages included with Amazon Linux AMI.

Build tools

AL2023/AL2 platforms have newer versions of the build tools: gradle, maven, and ant.

JAR file handling

On AL2023/AL2 platforms, if your source bundle (ZIP file) contains a single JAR file and no other files, Elastic Beanstalk no longer renames the JAR file to application.jar. Renaming occurs only if you submit a JAR file on its own, not within a ZIP file.

Port passing

On AL2023/AL2 platforms, Elastic Beanstalk doesn't pass a port value to your application process through the PORT environment variable. You can simulate this behavior for your process by configuring a PORT environment property yourself. However, if you have multiple processes, and you're counting on Elastic Beanstalk passing incremental port values to your processes (5000, 5100, 5200 etc.), you should modify your implementation. For details, expand the Reverse proxy configuration section in Extending Elastic Beanstalk Linux platforms.

Java 7

Elastic Beanstalk doesn't support an AL2023/AL2 Java 7 platform branch. If you have a Java 7 application, migrate it to Corretto 8 or Corretto 11.

The following table lists migration information for the AL2023/AL2 platform versions in the Tomcat platform.

Area Changes and information

Configuration options

On AL2023/AL2 platform versions, Elastic Beanstalk supports only a subset of the configuration options and option values in the aws:elasticbeanstalk:environment:proxy namespace. Here's the migration information for each option.

Option Migration information

GzipCompression

Unsupported on AL2023/AL2 platform versions.

ProxyServer

AL2023/AL2 Tomcat platform versions support both the nginx and the Apache HTTPD version 2.4 proxy servers. However, Apache version 2.2 isn't supported.

On Amazon Linux AMI platform versions, the default proxy was Apache 2.4. If you used the default proxy setting and added custom proxy configuration files, your proxy configuration should still work on AL2023/AL2. However, if you used the apache/2.2 option value, you now have to migrate your proxy configuration to Apache version 2.4.

The XX:MaxPermSize option in the aws:elasticbeanstalk:container:tomcat:jvmoptions namespace isn't supported on AL2023/AL2 platform versions. The JVM setting to modify the size of the permanent generation applies only to Java 7 and earlier, and is therefore not applicable to AL2023/AL2 platform versions.

Application path

On AL2023/AL2 platforms, the path to the application's directory on Amazon EC2 instances of your environment is /var/app/current. It was /var/lib/tomcat8/webapps on Amazon Linux AMI platforms.

The following table lists migration information for the AL2023/AL2 platform versions in the Node.js platform.

Area Changes and information

Installed Node.js versions

On AL2023/AL2 platforms, Elastic Beanstalk maintains several Node.js platform branches, and only installs the latest version of the Node.js major version corresponding with the platform branch on each platform version. For example, each platform version in the Node.js 12 platform branch only has Node.js 12.x.y installed by default. On Amazon Linux AMI platform versions, we installed the multiple versions of multiple Node.js versions on each platform version, and only maintained a single platform branch.

Choose the Node.js platform branch that corresponds with the Node.js major version that your application needs.

Apache HTTPD log file names

On AL2023/AL2 platforms, if you use the Apache HTTPD proxy server, the HTTPD log file names are access_log and error_log, which is consistent with all other platforms that support Apache HTTPD. On Amazon Linux AMI platform versions, these log files were named access.log and error.log, respectively.

For details about log file names and locations for all platforms, see How Elastic Beanstalk sets up CloudWatch Logs.

Configuration options

On AL2023/AL2 platforms, Elastic Beanstalk doesn't support the configuration options in the aws:elasticbeanstalk:container:nodejs namespace. Some of the options have alternatives. Here's the migration information for each option.

Option Migration information

NodeCommand

Use a Procfile or the scripts keyword in a package.json file to specify the start script.

NodeVersion

Use the engines keyword in a package.json file to specify the Node.js version. Be aware that you can only specify a Node.js version that correspondes with your platform branch. For example, if you're using the Node.js 12 platform branch, you can specify only a 12.x.y Node.js version. For details, see Specifying Node.js dependencies with a package.json file.

GzipCompression

Unsupported on AL2023/AL2 platform versions.

ProxyServer

On AL2023/AL2 Node.js platform versions, this option moved to the aws:elasticbeanstalk:environment:proxy namespace. You can choose between nginx (the default) and apache.

AL2023/AL2 Node.js platform versions don't support standalone applications that don't run behind a proxy server. On Amazon Linux AMI Node.js platform versions, this used to be possible through the none value of the ProxyServer option in the aws:elasticbeanstalk:container:nodejs namespace. If your environment runs a standalone application, update your code to listen to the port that the proxy server (nginx or Apache) forwards traffic to.

var port = process.env.PORT || 5000;

app.listen(port, function() {
  console.log('Server running at http://127.0.0.1:%s', port);
});

The following table lists migration information for the AL2023/AL2 platform versions in the PHP platform.

Area Changes and information

PHP file processing

On AL2023/AL2 platforms, PHP files are processed using PHP-FPM (a CGI process manager). On Amazon Linux AMI platforms we used mod_php (an Apache module).

Proxy server

AL2023/AL2 PHP platform versions support both the nginx and the Apache HTTPD proxy servers. The default is nginx.

Amazon Linux AMI PHP platform versions supported only Apache HTTPD. If you added custom Apache configuration files, you can set the ProxyServer option in the aws:elasticbeanstalk:environment:proxy namespace to apache.

The following table lists migration information for the AL2023/AL2 platform versions in the Python platform.

Area Changes and information

WSGI server

On AL2023/AL2 platforms, Gunicorn is the default WSGI server. By default, Gunicorn listens on port 8000. The port might be different than what your application used on the Amazon Linux AMI platform. If you're setting the WSGIPath option of the aws:elasticbeanstalk:container:python namespace, replace the value with Gunicorn's syntax. For details, see Python configuration namespaces.

Alternatively, you can use a Procfile to specify and configure the WSGI server. For details, see Configuring the WSGI server with a Procfile.

Application path

On AL2023/AL2 platforms, the path to the application's directory on Amazon EC2 instances of your environment is /var/app/current. It was /opt/python/current/app on Amazon Linux AMI platforms.

Proxy server

AL2023/AL2 Python platform versions support both the nginx and the Apache HTTPD proxy servers. The default is nginx.

Amazon Linux AMI Python platform versions supported only Apache HTTPD. If you added custom Apache configuration files, you can set the ProxyServer option in the aws:elasticbeanstalk:environment:proxy namespace to apache.

The following table lists migration information for the AL2023/AL2 platform versions in the Ruby platform.

Area Changes and information

Installed Ruby versions

On AL2023/AL2 platforms, Elastic Beanstalk only installs the latest version of a single Ruby version, corresponding with the platform branch, on each platform version. For example, each platform version in the Ruby 2.6 platform branch only has Ruby 2.6.x installed. On Amazon Linux AMI platform versions, we installed the latest versions of multiple Ruby versions, for example, 2.4.x, 2.5.x, and 2.6.x.

If your application uses a Ruby version that doesn't correspond to the platform branch you're using, we recommend that you switch to a platform branch that has the correct Ruby version for your application.

Application server

On AL2023/AL2 platforms, Elastic Beanstalk only installs the Puma application server on all Ruby platform versions. You can use a Procfile to start a different application server, and a Gemfile to install it.

On the Amazon Linux AMI platform, we supported two flavors of platform branches for each Ruby version—one with the Puma application server and the other with the Passenger application server. If your application uses Passenger, you can configure your Ruby environment to install and use Passenger.

For more information and examples, see Using the Elastic Beanstalk Ruby platform.