Getting Started with OpenNebula

OpenNebula is an open-source solution for the comprehensive management of virtualized data centers to enable the mixed use of private, public, and hybrid IaaS clouds.


The driver requires Python's lxml library to be installed. It also requires an OpenNebula installation running version 4.12.


The following example illustrates some of the options that can be set. These parameters are discussed in more detail below.

# Note: This example is for /etc/salt/cloud.providers or any file in the
# /etc/salt/cloud.providers.d/ directory.

  # Set up the location of the salt master

  # Define xml_rpc setting which Salt-Cloud uses to connect to the OpenNebula API. Required.
  xml_rpc: http://localhost:2633/RPC2

  # Define the OpenNebula access credentials. This can be the main "oneadmin" user that OpenNebula uses as the
  # OpenNebula main admin, or it can be a user defined in the OpenNebula instance. Required.
  user: oneadmin
  password: JHGhgsayu32jsa

  # Define the private key location that is used by OpenNebula to access new VMs. This setting is required if
  # provisioning new VMs or accessing VMs previously created with the associated public key.
  private_key: /path/to/private/key

  driver: opennebula

Access Credentials

The Salt Cloud driver for OpenNebula was written using OpenNebula's native XML RPC API. Every interaction with OpenNebula's API requires a username and password to make the connection from the machine running Salt Cloud to API running on the OpenNebula instance. Based on the access credentials passed in, OpenNebula filters the commands that the user can perform or the information for which the user can query. For example, the images that a user can view with a --list-images command are the images that the connected user and the connected user's groups can access.

Key Pairs

Salt Cloud needs to be able to access a virtual machine in order to install the Salt Minion by using a public/private key pair. The virtual machine will need to be seeded with the public key, which is laid down by the OpenNebula template. Salt Cloud then uses the corresponding private key, provided by the private_key setting in the cloud provider file, to SSH into the new virtual machine.

To seed the virtual machine with the public key, the public key must be added to the OpenNebula template. If using the OpenNebula web interface, navigate to the template, then click Update. Click the Context tab. Under the Network & SSH section, click Add SSH Contextualization and paste the public key in the Public Key box. Don't forget to save your changes by clicking the green Update button.


The key pair must not have a pass-phrase.

Cloud Profiles

Set up an initial profile at either /etc/salt/cloud.profiles or the /etc/salt/cloud.profiles.d/ directory.

  provider: my-opennebula-provider
  image: Ubuntu-14.04

The profile can now be realized with a salt command:

salt-cloud -p my-opennebula-profile my-new-vm

This will create a new instance named my-new-vm in OpenNebula. The minion that is installed on this instance will have a minion id of my-new-vm. If the command was executed on the salt-master, its Salt key will automatically be signed on the master.

Once the instance has been created with salt-minion installed, connectivity to it can be verified with Salt:

salt my-new-vm

OpenNebula uses an image --> template --> virtual machine paradigm where the template draws on the image, or disk, and virtual machines are created from templates. Because of this, there is no need to define a size in the cloud profile. The size of the virtual machine is defined in the template.

Required Settings

The following settings are always required for OpenNebula:

  xml_rpc: http://localhost:26633/RPC2
  user: oneadmin
  password: JHGhgsayu32jsa
  driver: opennebula

Required Settings for VM Deployment

The settings defined in the Required Settings section are required for all interactions with OpenNebula. However, when deploying a virtual machine via Salt Cloud, an additional setting, private_key, is also required:

  private_key: /path/to/private/key

Listing Images

Images can be queried on OpenNebula by passing the --list-images argument to Salt Cloud:

salt-cloud --list-images opennebula

Listing Locations

In OpenNebula, locations are defined as hosts. Locations, or "hosts", can be querried on OpenNebula by passing the --list-locations argument to Salt Cloud:

salt-cloud --list-locations opennebula

Listing Sizes

Sizes are defined by templates in OpenNebula. As such, the --list-sizes call returns an empty dictionary since there are no sizes to return.

Additional OpenNebula API Functionality

The Salt Cloud driver for OpenNebula was written using OpenNebula's native XML RPC API. As such, many --function and --action calls were added to the OpenNebula driver to enhance support for an OpenNebula infrastructure with additional control from Salt Cloud. See the OpenNebula function definitions for more information.