GPConfig (Groovy Production Config Builder)
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This project demonstrates a configuration builder using Groovy, and an example
build script for web app project with two-level-nested folder structure.

The configuration builder takes as input:

  - The various scoped config files in the config/ directory of the project
  - Gradle properties (e.g. defined in ~/.gradle/gradle.properties), specifically
    properties named "releaseEnvironment" and "releaseNode"

and produces the output:

  - properties.json file located in dist/$serviceName/properties.json

Example gradle.properties content
---------------------------------
releaseEnvironment=PROD
releaseNode=prod-app-1

Why Groovy?
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- Clean syntax for defining standard collections and placeholders ( ${___} )
- Supports complex expressions and nesting (e.g. "size": threadPoolSize * 2 + 10)
- Java-compatible, integrated naturally with Gradle
- Evaluation is easy to understand.  Basically each config is evaluated using bindings
  of previously bound values, producing a new list of bound values.

Order of config file evaluation
-------------------------------
The order can be seen in common.gradle, namely, in order:

  [ "dir": "$rootDirUnix/config/_default", "filename": "_default.groovy" ],
  [ "dir": "$rootDirUnix/config/_default", "filename": "${releaseEnv}.groovy" ],
  [ "dir": "$rootDirUnix/config/_default", "filename": "${releaseEnv}.${releaseNode}.groovy" ],
  [ "dir": "$rootDirUnix/config/$serviceNameWithWar", "filename": "_default.groovy" ],
  [ "dir": "$rootDirUnix/config/$serviceNameWithWar", "filename": "${releaseEnv}.groovy" ],
  [ "dir": "$rootDirUnix/config/$serviceNameWithWar", "filename": "${releaseEnv}.${releaseNode}.groovy" ],

See example configuration files in config/ and examine the final generated file.

Building notes
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This project currently is tied to Jetty (standalone, not embedded), IntelliJ, Cygwin environment.