README.md

Dropwizard Environment Config

NOTICE: This project will become end of life soon. Please checkout the successor to this project: https://github.com/tkrille/dropwizard-template-config. All users are encouraged to migrate to the new project.

Dropwizard ConfigurationFactory that allows specifying environment variables as values in YAML.

Setup

First add the dependency to your pom:

<dependency>
    <groupId>de.thomaskrille.dropwizard</groupId>
    <artifactId>dropwizard-environment-configuration</artifactId>
    <version>1.1</version>
</dependency>

To setup, simply set the EnvironmentConfigurationFactoryFactory as factory for configuration factories on the Bootstrap object:

@Override
public void initialize(final Bootstrap<Config> bootstrap) {
    ...
    bootstrap.setConfigurationFactoryFactory(new EnvironmentConfigurationFactoryFactory());
    ...
}

Using EnvironmentConfigurationFactory also honors configuration overrides via system properties as usual. Configuration overrides take precedence over values set via environment variables.

Usage

Environment variables can be specified in config.yaml by using the following "magic value":

$env:ENVIRONMENT_VARIABLE[:DEFAULT_VALUE]

Example:

array:
  - 1
  - $env:ARRAY_1
  - $env:ARRAY_2:default
object:
  a: 1
  b: $env:OBJECT_B
  c: $env:OBJECT_C:default

You can only replace the complete leaf value of the YAML tree. Inline replacements will not work:

# this will not work and leave the tokens as is
url: http://$env:HOST:$env:PORT/

See also #5.

You have to write valid YAML, i.e. the following will not work:

 array: [ 1, $env:array_1, $env:array_2:default]
 object: {a: 1, b: $env:object_b, c: $env:object_c:default}

Use quotes to make it valid:

 array: [ 1, "$env:array_1", '$env:array_2:default']
 object: {a: 1, b: "$env:object_b", c: '$env:object_c:default'}

Copyright Notice

This project is licensed under the Apache License, Version 2.0, January 2004, and uses software from the following 3rd parties:

• Coda Hale
• Yammer, Inc.

See LICENSE-3RD-PARTY and NOTICE-3RD-PARTY for the individual 3rd parties.