CloudStack#

Apache CloudStack exposes user data, metadata, user password, and account SSH key through the virtual router. The datasource obtains the virtual router address via DHCP lease information given to the instance. For more details on metadata and user data, refer to the CloudStack Administrator Guide.

The following URLs provide to access user data and metadata from the Virtual Machine. data-server. is a well-known hostname provided by the CloudStack virtual router that points to the next UserData server (which is usually also the virtual router).

http://data-server./latest/user-data
http://data-server./latest/meta-data
http://data-server./latest/meta-data/{metadata type}

If data-server. cannot be resolved, cloud-init will try to obtain the virtual router’s address from the system’s DHCP leases. If that fails, it will use the system’s default gateway.

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:

  • 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: 120

  • 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: 50

Example#

An example configuration with the default values is provided below:

datasource:
  CloudStack:
    max_wait: 120
    timeout: 50