extending_knife.md

To use a knife plugin programmatically, from any ruby script, you need first know the source of the plugin. you have to know the config options for all the command line arguments you are interested to use. All knife plugin use mixlib-cli interface, and the command line options can be found at the beginning of the file (convention), declared using option method. if you are curious take a look at mixlib-cli readme

1.require the corresponding plugin file

require '/path/to/plugin'

2. Load the corresponding class' dependencies

Knife::Plugin.load_deps

3. All those arguments that are not pass via flags are assigned via name_args. assign an array to it

plugin = Knife::Plugin.new
plugin.name_args = ['argument'] 

4. Assign all arguments that are passed via command line flags , using the config helper method

plugin.config[:argument] = 'value'

5. Run the plugin

plugin.run

Following is an example of bootstrapping using knife ssh, that i use to bootstrap LXC. for reference, knife-ssh configs plugin can be seen here.

require 'chef/knife/bootstrap'
Chef::Knife::Bootstrap.load_deps
plugin = Chef::Knife::Bootstrap.new
plugin.name_args = ['1.2.3.4'] # ip or hostname of the target node
plugin.config[:run_list] = ['role[base]'] # should be an array
plugin.config[:use_sudo] = true
plugin.config[:ssh_user] = 'ubuntu'
plugin.config[:ssh_password] = 'ubuntu'
plugin.run

Generally this is available as a helper method. where i can pass the ip and run list

require 'chef/knife/bootstrap'
Chef::Knife::Bootstrap.load_deps
def knife_bootstrap(ip, run_list)
  plugin = Chef::Knife::Bootstrap.new
  plugin.name_args = ['1.2.3.4'] # ip or hostname of the target node
  plugin.config[:run_list] = ['role[base]'] # should be an array
  plugin.config[:use_sudo] = true
  plugin.config[:ssh_user] = 'ubuntu'
  plugin.config[:ssh_password] = 'ubuntu'
  plugin.config[:use_sudo_password] = true
  plugin.config[:distro] = 'chef-full'
  plugin.run
end

knife_bootstrap('1.2.3.4', ['role[base]'])