New: Manage Free Templates for AWS CloudFormation with the widdix CLI

There are two approaches when it comes to managing EC2 instances: mutable and immutable.

A mutable EC2 instance is created once and then lives for many years. Humans log on to the machine (e.g., via SSH or RDP) and do their work. OS updates are applied to the running system; new packages are installed from time to time; configuration files are modified when needed. Deployments happen while the EC2 instance is running.

An immutable EC2 instance is never changed after creation. If you want to update the OS, you create a new EC2 instance that starts from a fresher image (AMI). If new packages are needed, a new AMI is created that contains those packages. If a new deployment is necessary, a new AMI is built and rolled out be replacing the EC2 instances. The EC2 instance is ephemeral and must not be used to persists data!

The EC2 templates follow both approaches, choose them according to your needs.

Template ID Template Description Approach
ec2/al2-mutable-public Amazon Linux 2 (mutable, public) mutable
ec2/al2-mutable-private Amazon Linux 2 (mutable, private) mutable
ec2/ec2-auto-recovery EC2 with auto-recovery immutable

Amazon Linux 2 (mutable, public)

This template describes an EC2 instance running Amazon Linux 2. If the instance fails it will be replaced automatically. All data stored on EBS volumes will still be available. The public and private IP addresses won't change. Auto-recovery does only work inside of a single availability zone (AZ). Backups happen during a backup window. OS Updates during maintenance window (Instance might be restarted). We recommend to use AWS Systems Manager to configure the instance.

Installation Guide

  1. This templates depends on one of our vpc-*azs.yaml templates. Launch Stack
  2. Launch Stack
  3. Click Next to proceed with the next step of the wizard.
  4. Specify a name and all parameters for the stack.
  5. Click Next to proceed with the next step of the wizard.
  6. Click Next to skip the Options step of the wizard.
  7. Check the I acknowledge that this template might cause AWS CloudFormation to create IAM resources. checkbox.
  8. Click Create to start the creation of the stack.
  9. Wait until the stack reaches the state CREATE_COMPLETE
  10. Grab the public PublicIPAddress of the EC2 instance from the Outputs tab of your stack.

Dependencies

Limitations

Amazon Linux 2 (mutable, private)

This template describes an EC2 instance running Amazon Linux 2. If the instance fails it will be replaced automatically. All data stored on EBS volumes will still be available. The private IP address won't change. Auto-recovery does only work inside of a single availability zone (AZ). Backups happen during a backup window. OS Updates during maintenance window (Instance might be restarted). We recommend to use AWS Systems Manager to configure the instance.

Installation Guide

  1. This templates depends on one of our vpc-*azs.yaml templates. Launch Stack
  2. Launch Stack
  3. Click Next to proceed with the next step of the wizard.
  4. Specify a name and all parameters for the stack.
  5. Click Next to proceed with the next step of the wizard.
  6. Click Next to skip the Options step of the wizard.
  7. Check the I acknowledge that this template might cause AWS CloudFormation to create IAM resources. checkbox.
  8. Click Create to start the creation of the stack.
  9. Wait until the stack reaches the state CREATE_COMPLETE
  10. Grab the private PrivateIPAddress of the EC2 instance from the Outputs tab of your stack.

Dependencies

Limitations

EC2 with auto-recovery

Deprecated in v11, will be removed in v13! Use ec2/al2-mutable-public or ec2/al2-mutable-private instead.

This template describes an EC2 instance with auto-recovery. If the instance fails it will be replaced automatically. All data stored on EBS volumes will still be available. The public and private IP address won't change. Auto-recovery does only work inside of a single availability zone (AZ).

Architecture

Installation Guide

  1. This templates depends on one of our vpc-*azs.yaml templates. Launch Stack
  2. Launch Stack
  3. Click Next to proceed with the next step of the wizard.
  4. Specify a name and all parameters for the stack.
  5. Click Next to proceed with the next step of the wizard.
  6. Click Next to skip the Options step of the wizard.
  7. Check the I acknowledge that this template might cause AWS CloudFormation to create IAM resources. checkbox.
  8. Click Create to start the creation of the stack.
  9. Wait until the stack reaches the state CREATE_COMPLETE
  10. Grab the public IPAddress of the EC2 instance from the Outputs tab of your stack.

Dependencies

Limitations