Finding the Right Ubuntu 20.04 LTS AMI for Your AWS Instance: A Guide to Terraform
Creating a new instance in AWS can be a straightforward process, but navigating the vast ocean of available Amazon Machine Images (AMIs) can feel overwhelming. If you're looking for the perfect Ubuntu 20.04 LTS AMI to power your AWS instance, this guide using Terraform will help you navigate the waters smoothly.
The Challenge: Finding the Perfect AMI
The challenge lies in finding an AMI that meets your specific requirements:
- Ubuntu 20.04 LTS: You need the latest Long-Term Support (LTS) version of Ubuntu.
- AWS: The AMI must be compatible with the Amazon Web Services platform.
- Specific Needs: You might have additional requirements like a particular instance type, storage configuration, or specific software packages pre-installed.
Understanding the Code and Terraform
Let's start with a basic Terraform code snippet that uses the aws_ami resource to find an Ubuntu 20.04 LTS AMI for AWS:
resource "aws_ami" "ubuntu_20_04_lts" {
most_recent = true
filter {
name = "name"
values = ["ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-*"]
}
owners = ["099720109477"] # Canonical's AWS account ID
}
resource "aws_instance" "example" {
ami = aws_ami.ubuntu_20_04_lts.id
instance_type = "t2.micro" # Replace with your desired instance type
# ...other configuration options
}
Explanation:
aws_amiresource: This resource helps us discover and manage AMIs within our AWS environment.most_recent: This attribute ensures we get the most up-to-date AMI matching our criteria.filter: This block allows us to filter the AMIs based on their names.name: We use "name" to target the AMI name filter.values: We specify a pattern to match against the AMI names. In this case, we're looking for AMIs that start with "ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-*".
owners: This attribute limits our search to AMIs owned by Canonical (Ubuntu's parent company), identified by their AWS account ID.aws_instance: This resource defines our EC2 instance, using theamiattribute to specify the selected AMI.
Additional Considerations and Refinement
Further Filtering:
- You can refine your search with more filters, such as the "virtualization-type" (hvm or paravirtual) or "root-device-type" (ebs or instance-store).
- Include additional
filterblocks to filter based on your exact requirements.
Other AMI Sources:
While this example uses Canonical's official AMIs, you might find it beneficial to explore:
- AWS Marketplace: Browse AMIs provided by other vendors, potentially including pre-configured software stacks.
- Community AMIs: Check out the AWS Community AMI (AMI) project for a wider selection.
Pre-configured AMIs:
If your needs are very specific, look for pre-configured AMIs with specific software stacks or configurations already installed, saving you time and effort during setup.
Best Practices
- Automation is key: Utilize Terraform to automate the AMI selection process, ensuring consistency and reducing manual errors.
- Regular updates: Keep track of the latest AMI releases and update your Terraform code to utilize newer, more secure versions.
- Documentation is essential: Clearly document your chosen AMIs and their configurations to maintain a consistent and reproducible environment.
Conclusion
Finding the perfect Ubuntu 20.04 LTS AMI for your AWS instance can be a quick and easy process when you leverage the power of Terraform. By utilizing the aws_ami resource and its filtering capabilities, you can confidently select the AMI that meets your specific needs. Remember to explore other AMI sources and utilize best practices to maintain an optimized and secure AWS environment.
