This setting is required when using the allocation action.
The value of this setting should correspond to a node setting on one or more nodes in your cluster.
For example, you might have set
elasticsearch.yml file for one or more of your nodes. To match
allocation in this case, set key to
These special attributes are also supported:
Match nodes by node name
Match nodes by host IP address (IP associated with hostname)
Match nodes by publish IP address
Match nodes by hostname
There is no default value. This setting must be set by the user or an exception will be raised, and execution will halt.