ratpack-configoverride-example

An example of layering configuration mechanisms in Ratpack.

This example starts a simple Ratpack application that loads a default database configuration from config.yaml. The default database configuration can be overridden by setting environment variables.

Running the Example

1. Start the example application by running the following command:

    $ ./gradlew run
   

2. Run the following curl command to retrieve the current database configuration:

    $ curl http://localhost:5050/config
   

   You should see the following:

    {
      "host": "localhost",
      "port": 5432,
      "username": "postgres",
      "password": "postgres",
      "database": "mydb"
    }
   

3. Stop the application.

4. Now assume that we want to override the default database port at runtime via environment variables. Start the application using the following command:

    $ RATPACK_DATABASE__PORT=8001 ./gradlew run
   

5. Run the curl command again to retrieve the current database configuration:

    $ curl http://localhost:5050/config
   

   Note that the default port has been overridden with 8001:

    {
      "host": "localhost",
      "port": 8001,
      "username": "postgres",
      "password": "postgres",
      "database": "mydb"
    }
   

Bugs and Feedback

For bugs, questions, and discussions please use the Github Issues.

License

MIT License

Copyright (c) 2018 Greg Whitaker

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.