picknroll

Keep environment specific attributes in separate configuration files and build desired config on demand.

Gem: http://rubygems.org/gems/pick_and_roll
gem install pick_and_roll

The problem

Michael and Scotty work on the same website.
Michael use url "http://localhost", Scotty - "http://website".
Configuration lives in repository.

Basically guys have to options:

1. store 2 configuration files and duplicate common settings
2. manually change url setting after checkout

Their problems may be overcome with the following solution:

1. Keep common settings in configuration file
2. Separate distinct settings to custom files: Michael.json and Scotty.json respectively
3. Build configuration result configuration file based on common and custom files on demand

Config splitting

Web.config:

<configuration>
  <appSettings>
    <add key="Language" value="@@language@@" />
    <add key="BaseUri" value="@@baseurl@@" />
  </appSettings>
</configuration>

config.json

{ "language":"C#" }

Michael.json:

{ "baseuri":"http://localhost" }

Scotty.json:

{
    "language":"Ruby"
    "baseuri":"http://website"
}

where config.json accumulates settings which is true for the majority, but should be customizable

Usage

PickAndRoll.new().go - will look for config.json and .json file as custom config
or
PickAndRoll.new('Scotty').go - will look for config.json and execute with Scotty.json file as custom config, overriding language setting

Configuration

All configuration files are in json format, process can be configured with .parconfig file:

{
    "customDir": "_configs",
    "config": "config.json",
    "files": [
        "app.generic.xml",
        "web.config"
    ]
}

customDir - path to directory with configuration files (default: _configs) config - path to file with common settings (default: config.json; expected to be placed inside customDir)
files - array of files to be parsed. If filename contain ".generic.", then new file without slug will be generated, otherwise values will be substituted in original file.

Example

.parconfig:

{
    "files": [
        "app.generic.xml",
        "web.config"
    ]
}

Web.generic.xml:

<configuration>
    <add key="BaseUri" value="@@baseurl@@" />
</configuration>

App.config:

<configuration>
    <add key="uri" value="@@baseurl@@" />
</configuration>

config.json:

{ "baseuri":"http://domain.name" }

Michael.json:

{ "baseuri":"http://localhost" }

If we run PickAndRoll on PC called Michael we'll get

web.generic.xml - untouched
web.xml:

<configuration>
    <add key="BaseUri" value="http://localhost" />
</configuration>

App.config:

<configuration>
    <add key="uri" value="http://localhost" />
</configuration>