The Ubuntu cloud image is the official image for AWS, Azure, GCP, and the other clouds. The right way to use it: pick the LTS (long-term support) version, use cloud-init for the initial configuration, and run the apt update before installing anything else.
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The Ubuntu cloud image
The Ubuntu cloud image is the official image published by Canonical for the cloud platforms. The image is designed to be a minimal starting point for a cloud VM; it has the Ubuntu base, the cloud-init package, and a few other tools.
The image is available for:
- AWS: the official AMI in the AWS Marketplace, and the AMI ID in the Canonical account.
- Azure: the official image in the Azure Marketplace.
- GCP: the official image in the GCP Marketplace.
- Other clouds: the official image in the cloud’s marketplace, or a direct download from cloud-images.ubuntu.com.
The LTS version
The LTS (long-term support) version is the right answer for most workloads. The LTS is supported for 5 years for the main version and 10 years for the LTS-pro (or the equivalent).
The non-LTS version is supported for 9 months. The non-LTS is the right answer for the team that wants the latest features and is willing to upgrade every 9 months.
cloud-init
cloud-init is the package that runs on the first boot of the cloud VM. cloud-init reads the user-data from the cloud platform and configures the VM: the hostname, the SSH keys, the packages, the services, the users.
The right way to use cloud-init: provide a user-data script (or a cloud-init config) that does the initial configuration. The script runs once, on the first boot, and the result is a VM that is ready to use.
The first boot
The first boot of the cloud VM:
- The cloud platform boots the VM.
- The cloud-init package runs.
- The cloud-init package reads the user-data.
- The cloud-init package configures the VM.
- The VM is ready.
The first boot can take 1-5 minutes, depending on the user-data and the cloud platform.
The apt update
The first thing to do after the VM is ready: apt update && apt upgrade.
The cloud image is built at a specific point in time. The packages in the image are the versions at that point. The apt update brings the packages up to date with the latest security patches.
The security
The security:
- The Ubuntu LTS version is supported for 5 years for the main version and 10 years for the LTS-pro. The team that is on the LTS is on a supported version.
- The Ubuntu Security Notices (USN) are the official security advisories. The team should subscribe to the USN mailing list.
- The unattended-upgrades package is the default for the cloud image. The package automatically installs the security updates.
- The team should monitor the VM for unpatched packages and for security advisories.
FAQ
What is the Ubuntu cloud image?
The official Ubuntu image published by Canonical for the cloud platforms (AWS, Azure, GCP, and others). The image is designed to be a minimal starting point for a cloud VM.
Which Ubuntu version should I use in the cloud?
The LTS version. The LTS is supported for 5 years for the main version and 10 years for the LTS-pro.
What is cloud-init?
The package that runs on the first boot of the cloud VM. cloud-init reads the user-data from the cloud platform and configures the VM.
How do I find the Ubuntu cloud image?
In the cloud’s marketplace, or directly from cloud-images.ubuntu.com. Canonical publishes the official images for the major clouds.
How do I keep the Ubuntu cloud image up to date?
apt update && apt upgrade on a regular schedule. The unattended-upgrades package is the default for the cloud image and automatically installs the security updates.
What is the difference between Ubuntu LTS and Ubuntu Pro?
Ubuntu LTS is supported for 5 years for the main version. Ubuntu Pro is supported for 10 years and includes additional security patches. The team that has a long-term workload should consider Ubuntu Pro.
If you are sizing a server tier for a new project, the RunxBuild hosting calculator is the place to model the line items. The instances, the images, the storage, the network - each one is a separate number, and the team’s mental model for the platform is the sum of those numbers. The RunxBuild dashboard is where the team sees the actual server fleet in one place.