Operating system images

STACKIT provides a continuous integration/deployment cycle by regularly building cloud images directly from the respective providers. The images are not customized by STACKIT and are the latest daily builds including the security patches and package updates. STACKIT supports and provides only the latest version and older still maintained versions.

Linux distribution and version	License information
CentOS Stream 10 CentOS Stream 9 CentOS Stream 9 ARM64	Licensing policy of CentOS
Debian 12 Debian 12 ARM64 Debian 11	License information of Debian
Ubuntu 24.04 Ubuntu 24.04 ARM64 Ubuntu 22.04 Ubuntu 22.04 ARM64 Ubuntu 20.04 Ubuntu 18.04	Intellectual property rights policy of Ubuntu
Fedora 42 Fedora 42 ARM64 Fedora 41	Legal resources of Fedora
Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 10 ARM64 Red Hat Enterprise Linux 9 Red Hat Enterprise Linux 9 ARM64 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 8 ARM64	Cloud software and services agreement
Rocky Linux 10 Rocky Linux 10 ARM64 Rocky Linux 9 Rocky Linux 9 ARM64 Rocky Linux 8	Licensing of Rocky Linux
AlmaLinux 10 AlmaLinux 10 Arm64 AlmaLinux 9 AlmaLinux 9 ARM64 AlmaLinux 8	licensing policy of AlmaLinux

The above images are provided by STACKIT as base images, which provides an unmodified base installation for individual customizations. Based on these images, the customer has full control and customization options with regard to the operating system and all applications running on it.

The following table shows the general characteristics of the instances:

Service	Description	Linux Server
STACKIT Portal	Central point of contact for administration with automatic provisioning and self-management	yes
Local user	Creation of local system users by customers possible	yes
Central user management	The user administration is taken over by a central authorization management on the part of STACKIT.	no
Fully operational image	The customer receives a VM with administrative rights and a configurable (host) firewall.	yes
Security-boosted operating system	All servers are rugged on the STACKIT side.	no
Security updates	Installation of OS security updates by STACKIT in the defined maintenance window.	no
Basic monitoring	STACKIT monitors the general functionality of the cloud infrastructure, system instances, disk read/write, S3 storage read/write and DNS	yes
Advanced monitoring	In addition to basic monitoring, STACKIT monitors the system instances operated by STACKIT.	no
Backup and restore	The customer can set up backups and restores individually	yes
Managed backup	Regular backup of system instances.	no

Rotation concept of the images and naming convention

The naming convention of the images consists of a combination of release name and existing version number, for example “Ubuntu 22.04”:

Release	Image name
CentOS Stream	CentOS Stream 10 CentOS Stream 9 ARM64 CentOS Stream 9
Debian	Debian 12 Debian 12 ARM64 Debian 11
Ubuntu	Ubuntu 24.04 Ubuntu 24.04 ARM64 Ubuntu 22.04 Ubuntu 22.04 ARM64 Ubuntu 20.04 Ubuntu 18.04
Fedora	Fedora 42 Fedora 42 ARM64 Fedora 41
Rocky Linux	Rocky Linux 10 Rocky Linux 10 ARM64 Rocky Linux 9 Rocky Linux 9 ARM64 Rocky Linux 8
AlmaLinux	AlmaLinux 10 AlmaLinux 10 ARM64 AlmaLinux 9 AlmaLinux 9 ARM64 AlmaLinux 8
Red Hat Enterprise Linux	Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 10 ARM64 Red Hat Enterprise Linux 9 Red Hat Enterprise Linux 9 ARM64 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 8 ARM64

Due to the fact that STACKIT only provides customers with the latest versions of distributions and older still supported versions, when major versions of distributions are available from vendors, out-of-date versions (past their expiration date) are no longer available through the user interface for the server creation process. You can use old image versions and create servers from them until the end of the extended support of this distribution if such support is available for them via API and CLI. Example:

A cropped row from a table detailing the Ubuntu 18.04 LTS release, "Bionic Beaver". The data shown includes its Release date of 2018-04-26, Standard support until 2023-04-26 for both Desktops and Servers, Extended security maintenance until 2028-04-26, and an Initial kernel version of 4.15.

Also, through this continuous integration/deployment cycle, when there is a new daily image release of any distribution provided by the vendors (which includes security patches and package updates), STACKIT releases that version as the latest and rolls back the old one. Old versions are not visible through the UI and are only accessible through the API and CLI. The name of the old versions is a combination of the release name and the date they were released, so that users can easily check the release notes for that particular daily build. Example: “Ubuntu 22.04 (2022-04-27)”:

A screenshot of a Unix/Linux terminal window displaying the output of an 'openstack image list' command, filtered to show various Ubuntu 22.04 images. The output lists image IDs, the name "Ubuntu 22.04" followed by a specific image creation or publication date in YYYY-MM-DD format (e.g., 2022-04-27, 2022-05-09, 2022-06-01), and a status column showing "active" for all listed images.

The latest is always the best, but if you want to find and use an old version of some image, you can do that. Please, see: Find old versions of an image.

Logging in (authentication) to the operating system

Authentication on the Linux operating system is initially possible via SSH key or username and password. To enable an initial login via SSH key, an SSH key must be stored. See: Generate and upload SSH keys.

Authentication via username and password via SSH is disabled by default for security reasons, use the web console for this purpose. See: Access your server using the web console.

Username for SSH access

Based on various VM images offered, user names may be required for the SSH login. These are listed below:

VM-Image	Default Username
Ubuntu	ubuntu
CentOS Stream	cloud-user
Debian	debian
Fedora	fedora
AlmaLinux	almalinux
Rocky Linux	rocky
Red Hat Enterprise Linux	cloud-user

Creating username and password with sudo permissions via cloud-init

To create a custom username and password with administrative privileges, use the following configuration. Add it to the cloud-init user data. This option is currently not available in the STACKIT Portal.

#cloud-config
users:
    - name: <user>
      groups: sudo #for RHEL distributions use "wheel" group
      shell: /bin/bash
      sudo: ["ALL=(ALL) NOPASSWD:ALL"]
      lock_passwd: false
      passwd: "<your password here>" # hashed version
chpasswd:
    expire: false

ssh_pwauth: true

(Paid) licenses for operating systems

The Linux operating systems provided are not licensed separately by STACKIT, with the exception of Red Hat Enterprise Linux. The same applies to any images provided by the customer. In each case, the customer is responsible for correct licensing, as this is outside the scope of STACKIT.

For Red Hat Enterprise Linux, the license granted to the customer is also subject to the additional terms and conditions of the cloud services subscription agreement set forth at Cloud Software and Services Agreement, which is concluded between the customer and Red Hat, Inc. by subscribing to the STACKIT Red Hat Enterprise Linux Service and which may be amended from time to time by Red Hat in its sole discretion (“End User Agreement”), as a condition to providing customers with access to the software and/or updates.

In addition, we would like to point out that all applications that are used on STACKIT VMs must also be licensed by the customer, if this is necessary.