How to get only the results of 'knife search' commands

Question

When we run knife search command, it is listing the number of items found. I don't want the number of items, instead i need only the results. How to get it. Example to say, I would like to get some return code or nil value for the below command.

$ knife search node "name:MyLinux AND role:java"
0 items found

Answer 1

You may use knife exec for this and use the exitmethod of ruby.

Example (even if it's try to undertand what you wish to accomplish with so few details/context):

knife exec -E "exit nodes.find('name:MyLinux AND role:java').count > 0"; echo $?

Which will return 0 if nothing is found and 1 if any number of nodes are found.

If you wish to do something to the nodes (like adding a recipe to the run_list):

knife exec -E "nodes.find('name:MyLinux AND role:java') { |n| n.run_list << 'cookbook::recipe'; n.save }"

Answer 2

The "X items found" is written to stderr, so it might be easier to just redirect it:

$ knife search node "name:MyLinux AND role:java" 2> /dev/null