Generic support for init.d scripts

[noelmcloughlin]

There are a number of formula which drop file into /etc/default/ because its needed for some situations (PATHs). *nix software is allowed to support two type of configurations-

1. software config: /etc/template/template.conf
2. system config (node, java, golang, PATHS, ENV). /etc/default/template.sh

The template formula needs to be extended for the second use case. The libtofs implementation can be extended here but dict and file naming conventions may need to be refactored.

For CentOS it is unclear if /etc/default or /etc/sysconfig is most appropriate so the directory for a system config file should be configurable.

Background:

Configuring init.d Scripts - http://wwudevops.github.io/curriculum/06_boot_filesystem.html#configuring-init-d-scripts

The Linux FileSystem Hierarchy Standard-

CentOS hier(7):

/etc. Contains configuration files which are local to the machine. Some larger software packages, like X11, can have their own subdirectories below /etc. Site-wide configuration files may be placed here or in /usr/etc. Nevertheless, programs should always look for these files in /etc and you may have links for these files to /usr/etc.

 /etc/opt. Host-specific configuration files for add-on applications installed in /opt.

FreeBSD hier(7):

/etc/ system configuration files and scripts

defaults/  default system configuration	files; see rc(8)

Darwin hier(7)

 /etc/         system configuration files and scripts

Ubuntu hier(7)

/etc Contains configuration files which are local to the machine. Some larger software packages, like X11, can have their own subdirectories below /etc. Site-wide configuration files may be placed here or in /usr/etc. Nevertheless, programs should always look for these files in /etc and you may have links for these files to /usr/etc.

/etc/opt.  
    Host-specific configuration files for add-on applications installed in /opt.