/var/lib/cfengine3/masterfiles

The /var/lib/cfengine3/masterfiles contains the component "promises" used to create the final promises file used by cf-agent, et al. See CFEngine Introduction and System Overview.

The component files are assembled on the cfengine hub using the bash script /usr/local/administration/bin/check_and_install_promises which firstly invokes m4 to assemble the file and then invokes cf-promises to sanity-check the result before installing the finished promises file into /var/lib/cfengine3/inputs from whence it is collected by cf-agent running on the client hosts.