> os_daemons have limited ability to request information from couch and
> they initiate.
> "Restart me if configuration section <section> changes" is one (the
> only?) example.
There are three types of requests an os_daemon can make: get config
variable, register to be restarted on config change, or log message.
The formats for each are:
Get config:
Req: ["get", Section]
Res: {"key1": "value", "key2": "value2"}
Req: ["get", Section, Key]
Res: "value"
Register for restart:
Req: ["register", Section]
# process is killed when Section changes.
Req: ["register", Section, Key]
# process is killed when Section.Key changes
Log
Req: ["log", Message]
# Message is logged at INFO level
Req: ["log", Message, Opts]
# Opts current supports a level key like:
# {"level": "error"} and then we log at that level
# log message is logged at specified level, or
# at info level if the level is invalid.
