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Upload a custom image

Find out how to upload custom images to centron: requirements, supported formats, uploading via Control Panel or URL, and important information.

Prerequisites​

Requirements for custom images at centron​

Custom images that you upload to centron must meet the following requirements:

  • Operating system: The images must contain a Unix-like operating system.
  • File format: Images must be in one of the following formats:
    • Raw (.img) with an MBR or GPT partition table
    • qcow2
    • VHDX
    • VDI
    • VMDK
  • Size: Images must not exceed 100 GB in uncompressed form, including the file system.
  • File system: Images must support the ext3 or ext4 file systems.
  • cloud-init: Images must have cloud-init 0.7.7 or later, cloudbase-init, coreos-cloudinit, ignition or bsd-cloudinit correctly installed and configured. If the default configuration of cloud-init is set so that the NoCloud data source is listed before the ConfigDrive data source, ccloud³ VMs created from your image may not function correctly.
  • SSH configuration: Images must have sshd installed and configured to run at boot time. Without sshd set up, you will not have SSH access to ccloud³ VMs created from this image, unless you restore access via the recovery console.

Custom images that meet these criteria can also be uploaded as compressed gzip or bzip2 files.

Warning: You must add an SSH key when creating ccloud³ VMs from a custom image. Password authentication is disabled by default on these ccloud³ VMs. You cannot reset the root password via the control panel. Official Unix-like OS images that are cloud-friendly can be found on OpenStack.

Uploading custom images using automation​

To use your images in the centron and ccloud³, please send them to us. We will check your images and make them available to you within 24 hours.

Uploading a custom image via the Control Panel​

To upload an image via the Control Panel, click on ‘Images’ in the main navigation bar and then on the tab for custom images.

There are two ways to upload a custom image here:

  1. Upload an image file directly by clicking the ‘Upload image’ button, which opens a file dialogue box, or by dragging and dropping the image file into the window.

Note: Some browsers have file size limits. If you are unable to upload a large file via your browser, you can host the file somewhere else and upload it via a URL. For example, upload your image to centron S3 Object Storage and make the file public, or use a file-sharing tool such as Dropbox. Make sure the URL ends with the file extension (e.g. beispiel.com/datei.raw instead of beispiel.com/datei.raw?dl=0).

  1. Enter the URL of an image file by clicking the "Import via URL" button. In the ‘Upload an image’ window that opens, enter the URL of the desired image into the text field and click Next. The Control Panel supports uploads from HTTP, HTTPS and FTP URLs.

Note: Importing a custom image via a URL will fail if the image is hosted on a CDN that does not support HEAD requests. If you are having trouble importing an image via a URL, try downloading the file and uploading it directly.

Once you have made your selection, a window will open in which you can enter details about your image.

Uploading an image​

  • Edit image name: This field is automatically populated with the name of the uploaded file, but can be edited manually.
  • Distribution: You can choose between Arch Linux, Fedora, Ubuntu, CentOS, Debian or Unknown.
  • Select a data centre region: Your image will initially be hosted in a single data centre of your choice, and you can transfer custom images to different data centres after uploading.
  • Tags (optional): Custom images support tagging. You can add tags to your custom image here, or do so at any time after uploading.
  • Notes (optional): This is a text field where you can enter additional comments about your custom image for your own reference.

Once you have entered these details, click on ‘Upload image’. A progress bar will appear in the Control Panel next to the ‘Upload image’ button. If you click on the ‘Details’ button above this progress bar, a window will open listing all your current uploads.

You can cancel any upload in progress by clicking on the X shown here, or click on ‘Cancel uploads’ to stop all uploads currently in progress.

Once you have added at least one custom image to your account, you can create a ccloud³ VM from a custom image.

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