An automatic attribute is a specific detail about a node, such as an IP address, a host name, a list of loaded kernel modules, and so on. Automatic attributes are detected by Ohai and are then used by Chef Infra Client to ensure that they are handled properly during every Chef Infra Client run. The most commonly accessed automatic attributes are:
| Attribute | Description |
|---|---|
node['platform'] |
The platform on which a node is running. This attribute helps determine which providers will be used. |
node['platform_family'] |
The platform family is a Chef Infra specific grouping of similar platforms where cookbook code can often be shared. For example, `rhel` includes Red Hat Linux, Oracle Linux, CentOS, and several other platforms that are almost identical to Red Hat Linux. |
node['platform_version'] |
The version of the platform. This attribute helps determine which providers will be used. |
node['ipaddress'] |
The IP address for a node. If the node has a default route, this is the IPV4 address for the interface. If the node does not have a default route, the value for this attribute should be nil. The IP address for default route is the recommended default value. |
node['macaddress'] |
The MAC address for a node, determined by the same interface that detects the node['ipaddress']. |
node['fqdn'] |
The fully qualified domain name for a node. This is used as the name of a node unless otherwise set. |
node['hostname'] |
The host name for the node. |
node['domain'] |
The domain for the node. |
node['recipes'] |
A list of recipes associated with a node (and part of that node's run-list). |
node['roles'] |
A list of roles associated with a node (and part of that node's run-list). |
node['ohai_time'] |
The time at which Ohai was last run. This attribute is not commonly used in recipes, but it is saved to the Chef Infra Server and can be accessed using the knife status subcommand. |