OpenStack

This datasource supports reading data from the OpenStack Metadata Service.

Discovery

To determine whether a platform looks like it may be OpenStack, cloud-init checks the following environment attributes as a potential OpenStack platform:

  • Maybe OpenStack if
    • non-x86 cpu architecture: because DMI data is buggy on some arches
  • Is OpenStack if x86 architecture and ANY of the following
    • /proc/1/environ: Nova-lxd contains product_name=OpenStack Nova
    • DMI product_name: Either Openstack Nova or OpenStack Compute
    • DMI chassis_asset_tag is OpenTelekomCloud, SAP CCloud VM, OpenStack Nova (since 19.2) or OpenStack Compute (since 19.2)

Configuration

The following configuration can be set for the datasource in system configuration (in /etc/cloud/cloud.cfg or /etc/cloud/cloud.cfg.d/).

The settings that may be configured are:

  • metadata_urls: This list of urls will be searched for an OpenStack metadata service. The first entry that successfully returns a 200 response for <url>/openstack will be selected. (default: [’http://169.254.169.254’]).
  • max_wait: the maximum amount of clock time in seconds that should be spent searching metadata_urls. A value less than zero will result in only one request being made, to the first in the list. (default: -1)
  • timeout: the timeout value provided to urlopen for each individual http request. This is used both when selecting a metadata_url and when crawling the metadata service. (default: 10)
  • retries: The number of retries that should be done for an http request. This value is used only after metadata_url is selected. (default: 5)
  • apply_network_config: A boolean specifying whether to configure the network for the instance based on network_data.json provided by the metadata service. When False, only configure dhcp on the primary nic for this instances. (default: True)

An example configuration with the default values is provided below:

datasource:
  OpenStack:
    metadata_urls: ["http://169.254.169.254"]
    max_wait: -1
    timeout: 10
    retries: 5
    apply_network_config: True

Vendor Data

The OpenStack metadata server can be configured to serve up vendor data which is available to all instances for consumption. OpenStack vendor data is, generally, a JSON object.

cloud-init will look for configuration in the cloud-init attribute of the vendor data JSON object. cloud-init processes this configuration using the same handlers as user data, so any formats that work for user data should work for vendor data.

For example, configuring the following as vendor data in OpenStack would upgrade packages and install htop on all instances:

{"cloud-init": "#cloud-config\npackage_upgrade: True\npackages:\n - htop"}

For more general information about how cloud-init handles vendor data, including how it can be disabled by users on instances, see Vendor Data.

OpenStack can also be configured to provide ‘dynamic vendordata’ which is provided by the DynamicJSON provider and appears under a different metadata path, /vendor_data2.json.

Cloud-init will look for a cloud-init at the vendor_data2 path; if found, settings are applied after (and, hence, overriding) the settings from static vendor data. Both sets of vendor data can be overridden by user data.