Operating system images

An image is the operating system an instance starts from. You choose one in the Operating system section of the order page when you create an instance, and you can rebuild onto another later. The API calls an image a template.

The order page lists every image that is ready to build, grouped by distribution with the newest release first. The images on offer change over time, so the order page and GET /api/v1/client/vps/templates are the list to trust.

An image with any other slug is listed after these, under its own name.

We hand these settings to cloud-init in the image when we build the instance:

Default user

The image's own default account, such as root or the distribution's usual user. The order page shows it as "Sign in as" and the Access tab shows it as Username.

Password

A random password for the default user. We store it but do not show it. Reset the password to get one you can read.

SSH keys

The public keys you pasted in the Settings section of the order page, added to the default user's authorized_keys.

Hostname

The hostname you chose in the Settings section.

Network

The instance's primary address, gateway and mask, once an address is attached. Where the instance has IPv6, also its IPv6 address with the prefix length /64 and the gateway fe80::1.

DNS resolvers

1.1.1.1 and 8.8.8.8.

The dashboard also talks to the QEMU guest agent inside the instance, to read its operating system and addresses and to reset its password. Under Advanced on the Console tab, the System report card shows Reporting when the agent answers.

An image can need a minimum disk and memory. The Operating system section of the order page shows a release the plan is too small for, with the reason under it, and does not let you pick it:

The Rebuild operating system card on the Access tab does the same for an instance you already have, as Rebuild an instance describes.

GET /api/v1/client/vps/templates lists the images you can order or rebuild onto: every enabled image that at least one of our hosts can build now.

curl https://api.coritan.com/api/v1/client/vps/templates \
  -H "Authorization: Bearer $CORITAN_TOKEN"

[
  {
    "id": 7,
    "name": "Ubuntu 24.04 LTS",
    "slug": "ubuntu-24-04",
    "os_family": "linux",
    "os_version": "24.04",
    "default_username": "ubuntu",
    "min_cpu": 1,
    "min_memory_mb": 1024,
    "min_disk_gb": 10,
    "ready_nodes": 3
  }
]

id

The value to send as template_id when you order or rebuild.

name, slug

The image's name and its short identifier. The slug's first part names the distribution.

os_family

linux, windows or bsd.

os_version

The release, such as 24.04.

default_username

The user cloud-init sets up and the one you sign in as.

min_cpu, min_memory_mb, min_disk_gb

The smallest plan the image runs on.

ready_nodes

How many of our hosts can build the image now. An image that is ready somewhere may still not be ready in the location you want; an order for it there answers 422 with OS template 7 is not ready in location 'fra'.

Add uuid, the ID of one of your instances, to learn which images a rebuild of that instance accepts:

curl "https://api.coritan.com/api/v1/client/vps/templates?uuid=$INSTANCE_UUID" \
  -H "Authorization: Bearer $CORITAN_TOKEN"

Each image then also carries two fields. An instance that is not yours answers 404.

fits

true when a rebuild of the instance accepts the image.

unfit_reason

null when the image fits. Otherwise it is the sentence a rebuild with the image answers, such as Rocky Linux 9 is not ready for this instance yet. Choose another operating system, or try again later.