Preparing Linux templates

As all Linux guests have OpenSSH Server preinstalled by default, you only need to ensure that a Linux template has cloud-init installed.

Cloud-init is required to configure user credentials and SSH access for virtual machines created from cloud images.

The easiest way to get a Linux template with cloud-init installed is to obtain it from its official repository. You can also create a Linux template from an existing boot volume.

Using cloud-init with Linux cloud images

When deploying virtual machines from Linux cloud images (for example, Debian or Ubuntu), cloud-init applies the initial system configuration.

Cloud images do not contain predefined credentials. User accounts, passwords, and SSH settings are defined through cloud-init.

Access to such virtual machines is typically provided in one of the following ways:

• by injecting an SSH key
• by specifying user credentials in a cloud-init configuration

SSH keys selected at deployment are automatically injected into the guest operating system via cloud-init.

If neither a cloud-init configuration nor an SSH key is provided, you may not be able to log in to the virtual machine.

The following example creates a user account, sets a password, and enables SSH password authentication:

#cloud-config
users:
  - name: clouduser
    groups: sudo
    shell: /bin/bash
    sudo: ALL=(ALL) NOPASSWD:ALL
    lock_passwd: false

ssh_pwauth: true

chpasswd:
  expire: false
  list: |
    clouduser:<password>

runcmd:
  - systemctl restart ssh

Replace <password> with a secure password.

Cloud-init configuration is provided when creating the virtual machine. For details, refer to Creating virtual machines.