You may need to create a template in these cases:
- To rescue a virtual machine
- To create a VM accessible via SSH
- To create a VM customizable with user data
To prepare a template, you need to install cloud-init and OpenSSH Server in an existing boot volume, and then create an image from this volume.
Preparing Linux templates
As all Linux guests have OpenSSH Server preinstalled by default, you only need to make sure a Linux template has cloud-init installed.
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.
Preparing Windows templates
Windows guests have neither Cloudbase-Init nor OpenSSH Server preinstalled by default. You need to install and configure them manually.
To install Cloudbase-Init and OpenSSH Server inside a Windows virtual machine
- Log in to a Windows VM.
- Create a new administrator account that will be used for SSH connections and log in with it.
- To install and configure OpenSSH Server:
- Run Windows PowerShell with administrator privileges and set the execution policy to unrestricted to be able to run scripts:
> Set-ExecutionPolicy Unrestricted
- Download OpenSSH Server (for example, from the GitHub repository), extract the archive into the C:Program Files directory, and then install it by running:
> & 'C:Program FilesOpenSSH-Win64install-sshd.ps1'
- Start the
sshd
service and set its startup type to “Automatic”:> net start sshd > Set-Service sshd -StartupType Automatic
- Open TCP port 22 for the OpenSSH service in the Windows Firewall:
- On Windows 8.1, Windows Server 2012, and newer versions, run
> New-NetFirewallRule -Protocol TCP -LocalPort 22 -Direction Inbound -Action Allow -DisplayName OpenSSH
- On Windows 7, Windows Server 2008, and Windows Server 2008 R2, run
> netsh advfirewall firewall add rule name=sshd dir=in action=allow protocol=TCP localport=22
- On Windows 8.1, Windows Server 2012, and newer versions, run
- Open the C:ProgramDatasshsshd_config file:
> notepad 'C:ProgramDatasshsshd_config'
Comment out the following lines at the end of the file:
#Match Group administrators #AuthorizedKeysFile __PROGRAMDATA__/ssh/administrators_authorized_keys
Save the changes.
- Create the .ssh directory in C:Users<current_user> and an empty authorized_keys file inside it:
> cd C:Users<current_user> > mkdir .ssh > notepad ..sshauthorized_keys
Remove the .txt extension from the created file:
> move ..sshauthorized_keys.txt ..sshauthorized_keys
- Modify the permissions for the created file to disable inheritance:
> icacls ..sshauthorized_keys /inheritance:r
- Run Windows PowerShell with administrator privileges and set the execution policy to unrestricted to be able to run scripts:
- Download Cloudbase-Init (for example, from the official site), launch the installation, and then follow the on-screen instructions:
- In the Configuration options window, enter the current username in the Username field:
- When the installation is complete, do not run Sysprep and click Finish.
- Run Windows PowerShell with administrator privileges and open the file C:Program FilesCloudbase SolutionsCloudbase-Initconfcloudbase-init.conf:
> notepad 'C:Program FilesCloudbase SolutionsCloudbase-Initconfcloudbase-init.conf'
Add
metadata_services
andplugins
on two lines:metadata_services= cloudbaseinit.metadata.services.configdrive.ConfigDriveService, cloudbaseinit.metadata.services.httpservice.HttpService plugins=cloudbaseinit.plugins.common.mtu.MTUPlugin, cloudbaseinit.plugins.windows.ntpclient.NTPClientPlugin, cloudbaseinit.plugins.common.sethostname.SetHostNamePlugin, cloudbaseinit.plugins.windows.createuser.CreateUserPlugin, cloudbaseinit.plugins.common.networkconfig.NetworkConfigPlugin, cloudbaseinit.plugins.windows.licensing.WindowsLicensingPlugin, cloudbaseinit.plugins.common.sshpublickeys.SetUserSSHPublicKeysPlugin, cloudbaseinit.plugins.windows.extendvolumes.ExtendVolumesPlugin, cloudbaseinit.plugins.common.setuserpassword.SetUserPasswordPlugin, cloudbaseinit.plugins.common.userdata.UserDataPlugin, cloudbaseinit.plugins.windows.winrmlistener.ConfigWinRMListenerPlugin, cloudbaseinit.plugins.windows.winrmcertificateauth. ConfigWinRMCertificateAuthPlugin, cloudbaseinit.plugins.common.localscripts.LocalScriptsPlugin
Save the changes.
- In the Configuration options window, enter the current username in the Username field:
- Stop the VM.
- After the VM is shut down, convert its boot volume to a template, as described in Creating images from volumes.