能否通过Elastic Beanstalk配置启用T2 Unlimited实例（无需事后配置）？

Absolutely! You can enable T2 Unlimited directly through Elastic Beanstalk (EB) configurations—no need to wait for instances to finish launching and adjust settings afterward. Here are the most straightforward methods to set this up:

1. Configure via Elastic Beanstalk Console #

• Open the Elastic Beanstalk console and select your target environment.
• Navigate to the Configuration tab, locate the Capacity section, and click Edit.
• In the Instance type area, find your T2 instance type, then check the Enable unlimited mode checkbox.
• Click Apply to save the changes. EB will automatically update existing instances and ensure all future launched instances use T2 Unlimited mode.

2. Use .ebextensions for Code-Based Configuration #

For a reproducible, version-controlled setup, add an .ebextensions configuration file to your application bundle:

Create a file named .ebextensions/t2-unlimited.config with the following content:

Resources:
  AWSEBAutoScalingLaunchConfiguration:
    Properties:
      InstanceType: t2.micro  # Replace with your actual T2 instance type (e.g., t2.small)
      CreditSpecification:
        CPUCredits: unlimited

When you deploy your application to EB, this config will automatically set the launch configuration to enable T2 Unlimited. All instances launched by the environment—whether initial creation or auto-scaling events—will inherit this setting.

3. Update via AWS CLI #

If you prefer command-line operations, use the AWS CLI to modify your environment's settings directly:

aws elasticbeanstalk modify-environment \
  --environment-name YOUR_ENVIRONMENT_NAME \
  --option-settings Namespace=aws:autoscaling:launchconfiguration,OptionName=InstanceType,Value=t2.micro \
  --option-settings Namespace=aws:autoscaling:launchconfiguration,OptionName=CPUCredits,Value=unlimited

Make sure to replace YOUR_ENVIRONMENT_NAME and t2.micro with your environment's name and your chosen T2 instance type.

Note: T2 Unlimited mode is only available for T2 instance types. Keep in mind that this mode may incur additional costs if your instances consume more CPU credits than they earn over time, but it eliminates the need for post-launch configuration tweaks for bursty workloads.

内容的提问来源于stack exchange，提问作者Stein Inge Morisbak