Prepare ISO image to work with the cloud platform

Last update: April 08 2024

Prepare ISO image to work with the cloud platform

If you have uploaded to the image repository an ISO image with an operating system distribution, we recommend making it fully compatible with the Selectel Cloud Platform. From a compatible image, you can create cloud servers for which the same functionality is available as servers from out-of-the-box images.

For your information

These are the instructions for the Oracle Linux image. Utilities, repositories, and file locations may differ for other distributions.

1. Upload the ISO image to the image store.
2. Create a cloud server from the downloaded image.
3. Configure cloud server.
4. Create an image from the cloud server boot disk.

1. Download the ISO image to the image repository at⁠

Use the Download and create image instructions.

2. Create a cloud server from the downloaded image⁠

Use the Create cloud server instruction.

Select the downloaded image as the source and the network drive as the boot disk.

3. Set up a cloud server⁠

1. Connect to cloud server.

2. Add the OpenStack Selectel repositories to the selectel-openstack.repo file:

   cat <<EOF > /etc/yum.repos.d/selectel-openstack.repo
   [selectel-openstack]
   name=selectel-openstack
   baseurl=http://repo.os.selectel.org/rpm/centos/7/x86_64
   gpgcheck=1
   gpgkey=http://repo.os.selectel.org/selectel-openstack.key
   EOF

3. Update the list of repositories for the package manager:

   yum update

4. Install the packages:

   yum install crontab-randomizer {
   fstrim-blocks qemu-guest-agent {
   set-root-pw {
   cloud-init {
   cloud-utils-growpart {
   compat-openssl10

5. Navigate to the /etc/cloud/cloud.cfg.d/ directory to create the cloud-init configuration files:

   cd /etc/cloud/cloud.cfg.d/

6. Prevent the ubuntu user from being created:

   cat <<EOF > 10_no_default_users.cfg
   users: []
   EOF

7. Add data sources for cloud-init-datasources:

   cat <<EOF > 91-dib-cloud-init-datasources.cfg
   datasource_list: [ ConfigDrive, Ec2, None ]
   EOF

8. Disable the cloud-init and EC2 warning:

   cat <<EOF > 92-ec2-datasource.cfg
   #cloud-config
   datasource:
       Ec2:
           strict_id: false
   EOF

9. Add download settings:

   cat <<EOF > 99_boot_routines.cfg
   bootcmd:
       - sed -i '/^;/d' /etc/resolv.conf
   EOF

10. Prevent cloud-init from disabling EC2 metadata:

    cat <<EOF > 99_enable_ec2.cfg
    disable_ec2_metadata: false
    EOF

11. Add first-boot settings:

    cat <<EOF > 99_first_boot_routines.cfg
    runcmd:
        - sed -i '/NetworkManager/d' /etc/resolv.conf
        - sed -i '/^nameserver 10\./d' /etc/resolv.conf
        - sed -i '/^nameserver 192\./d' /etc/resolv.conf
        - sed -i '/^nameserver 172\./d' /etc/resolv.conf
        - sed -i '/^search/d' /etc/resolv.conf
        - set-root-pw 2> /dev/null
        - crontab-randomizer
    EOF

12. Prohibit disabling root access via SSH:

    cat <<EOF > 99_keep_root_user.cfg
    disable_root: false
    EOF

13. Change the timezone:

    cat <<EOF > 99_location.cfg
    locale: en_US.UTF-8
    timezone: UTC
    EOF

14. Add permission for password authentication via SSH:

    cat <<EOF > 99_ssh_settings.cfg
    ssh_pwauth: true
    no_ssh_fingerprints: true
    ssh_deletekeys: true
    EOF

15. Configure services autorun to apply changes and work correctly after a server reboot:

    systemctl enable cloud-init
    systemctl enable cloud-init.service
    systemctl enable cloud-config.service
    systemctl enable cloud-final.service
    systemctl enable qemu-guest-agent.service
    systemctl enable cockpit.socket

16. Perform a hardware reboot of the server.

17. Re-connect to cloud server.

    A message will appear indicating that the host ID has changed. This means that cloud-init is successful in booting the operating system:

    @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
    @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
    @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
    IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
    Someone could be eavesdropping on you right now (man-in-the-middle attack)!
    It is also possible that a host key has just been changed.

4. Create an image from the cloud server boot disk⁠

1. Create an image from the cloud server boot disk.

2. Open OpenStack CLI.

3. Add properties for the created image:

   glance image-update --property x_sel_image_owner=Selectel <image>
   glance image-update --property hw_qemu_guest_agent=yes <image>

   Specify <image> — ID or image name, can be viewed with openstack image list --private.

4. Optional: after creating an image from disk delete cloud server.