3.17. Starting a Virtual Machine with Cloud-Init


This Ruby example starts a virtual machine using the Cloud-Init tool to set the root password and network configuration.

# Find the virtual machine:
vms_service = connection.system_service.vms_service
vm = vms_service.list(search: 'name=myvm')[0]

# Find the service that manages the virtual machine:
vm_service = vms_service.vm_service(vm.id)

# Create a cloud-init script to execute in the
# deployed virtual machine. The script must be correctly
# formatted and indented because it uses YAML.
my_script = "
write_files:
  - content: |
      Hello, world!
    path: /tmp/greeting.txt
    permissions: '0644'
"

# Start the virtual machine, enabling cloud-init and providing the
# password for the `root` user and the network configuration:
vm_service.start(
  use_cloud_init: true,
  vm: {
    initialization: {
      user_name: 'root',
      root_password: 'redhat123',
      host_name: 'myvm.example.com',
      nic_configurations: [
        {
          name: 'eth0',
          on_boot: true,
          boot_protocol: OvirtSDK4::BootProtocol::STATIC,
          ip: {
            version: OvirtSDK4::IpVersion::V4,
            address: '192.168.0.100',
            netmask: '255.255.255.0',
            gateway: '192.168.0.1'
          }
        }
      ],
      dns_servers: '192.168.0.1 192.168.0.2 192.168.0.3',
      dns_search: 'example.com',
      custom_script: my_script
    }
  }
)

For more information, see VmService:start.

Red Hat logoGithubRedditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat Documentation

Legal Notice

Theme

© 2026 Red Hat
Back to top