dockerconfig

• easy nodejs config for docker (overwrite with ENV vars)
• updated: you must not use "_" in your variable names
• check ./test if you dont understand the readme example (you can run "npm test" to try it)

//somewhere in your init script/class

const dockerconfig = require("dockerconfig");

//myConfigData = { port: 1234, nested: { something: "no" } };
const myConfigData = require("./config.json");
const config = dockerconfig.getConfig(myConfigData);
config.makeGlobal();

//somewhere else

console.log(CONFIG.port);
console.log(CONFIG.nested.something);

//your dockerfile

FROM node:6-onbuild

# building & run docker image
# with environment variables to overwrite config data

docker build -t my-config-test .
docker run -e NODE_CONFIG_PORT=5555 -e NODE_CONFIG_NESTED_SOMETHING=yes my-config-test

# outputs:

# 555 instead of 1234
# "yes" instead of "no"

config versioning

• new in 1.4.0
• optional

Versioning helps you to keep application-image and deployment-configuration (via environment-variables) in sync, since it's not always possible to keep all config-changes backwards-compatible or provide sane defaults.

Usage

In your application/image add a key configVersion to your config.json (or rather: config-object). The configVersion must be a number, using timestamps is recommended:

{
  "configVersion": 1464091200
}

Next add the environment variable NODE_CONFIG_CONFIGVERSION with the very same value when running your container:

$ docker run -e NODE_CONFIG_CONFIGVERSION=1464091200 my-application 

Now dockerconfig.getConfig() will throw an exception on version-mismatch.

Authors

• Christian Fröhlingsdorf, chris@5cf.de (original author)
• Elmar Athmer, elmar@athmer.org (contributor)