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An attribute is a specific detail about a node. Attributes are used by Chef Infra Client to understand:

• The current state of the node
• What the state of the node was at the end of the previous Chef Infra Client run
• What the state of the node should be at the end of the current Chef Infra Client run

Attributes are defined by:

• The node as saved on the Chef Infra Server
• Attributes passed via JSON on the command line
• Cookbooks (in attribute files and/or recipes)
• Policyfiles

During every Chef Infra Client run, Chef Infra Client builds the attribute list using:

• Attributes passed via JSON on the command line
• Data about the node collected by Ohai.
• The node object that was saved to the Chef Infra Server at the end of the previous Chef Infra Client run.
• The rebuilt node object from the current Chef Infra Client run, after it is updated for changes to cookbooks (attribute files and/or recipes) and/or Policyfiles, and updated for any changes to the state of the node itself.

After the node object is rebuilt, all of the attributes are compared, and then the node is updated based on attribute precedence. At the end of every Chef Infra Client run, the node object that defines the current state of the node is uploaded to the Chef Infra Server so that it can be indexed for search.