Enable bastion server for Chef knife

knife.rb

# ...
# your knife configurations goes here
# ...

# Bastion host SSH settings
knife[:bastion_host] = "bastion.mycorp.net"
knife[:bastion_user] = ENV["MYCORP_USER"] || ENV["CHEF_USER"] || ENV["USER"]

# If you have multiple networks, that require different MFA tokens, specify
# each network name here. (This configuration is referenced to clarify the
# token a user should employ.)
# knife[:bastion_network] = "mynet"

# By default, the proxy server is created on port 4443. You may configure the
# local bastion port here:
# knife[:bastion_local_port] = 4443

require "knife-bastion/activate"