Basic Sources
Command line argument source
This source allows conferer to read configuration from the CLI aguments:
It maps arguments starting like --key.sub=value into key "key.sub" with value "value"
it ignored anything that doesn't have a -- at the beginning and if the = is not present
then the value is "true" (as the usual convention on for CLIs)
Environment source
This source allows conferer to read configuration from environment variables:
It maps keys to a common format for env vars by:
- Uppercase everything (
server.port=>SERVER.PORT) - Join key into a big string using underscores (
"SERVER.PORT"=>"SERVER_PORT")
NOTE: The default config combines this Source so env vars are scoped using the
application name so server.port => AWESOMEAPP_SERVER_PORT.
Properties file source
This source allows conferer to read configuration from .properties file:
NOTE: This source is quite rigid now, in the future when we see how users use this module we'll expand it
This module is configured recursively, it uses the "env" key to find out which file to use
like config/${env}.properties, so if it's set to production the file will be
config/production.properties. If no env key is set, "development" will be used.
The User (or The Programmer) can also provide a Key to look for a filepath pointing to the
configuration file, so setting config.file=somefile.properties will use that file ignoring
the "env" key.
The format of the file is as follows:
key.sub=value
other.key.sub=value
some.key= 74
There are no comments and spaces are not trimmed so "some.key"'s value will be " 74" instead
of "74". Blank lines are ignored. (May be configurable in the future)
This format is pretty restricted, I plan to improve it further in later versions but for now it's enough and there are other more standard formats that are capable of representing everything as well.