Osseus Config

The osseus configuration module parses:

• Environment variables
• Environment specific files
• AWS Secrets
• CLI arguments

The result is an object which will be used by other osseus modules.

Note: all keys will be lowercased in the result object

Install

$ npm install @colucom/osseus-config

Usage

First, create index.js:

const OsseusConfig = require('osseus-config')
const config = await OsseusConfig.init()
console.log(config)

Special Properties

hostInfo

You can use the hostInfo property in the osseus.config object.

In case your app is running on:

• localhost
  • hostname is the machine name
• aws
  • hostname is the instance id

These props can be accessed by: osseus.config.hostInfo.hostname and osseus.config.hostInfo.pid

Environment variables

Environment variables must have a CFG_ prefix in order to be parsed by osseus-config

Example

Running:

$ export CFG_SOME_VAR=value
$ node index.js

Will result in:

{ some_var: 'value', keys: [ 'some_var' ] }

Environment specific files

Environment files should be placed under /config folder in the root of the application.

In order for environment files to be parsed, need to define ENV variable matching the file name.

Example

Create /config/LOCAL.js

module.exports = {
  DEBUG: true,
  OSSEUS_LOGGER_LOG_LEVEL: 'debug',
  OSSEUS_SERVER_PORT: '8888'
}

Running:

$ export CFG_ENV=LOCAL
$ node index.js

Will result in:

{ env: 'LOCAL',
  debug: true,
  osseus_logger: { log_level: 'debug' },
  osseus_server: { port: 8888 },
  keys: [ 'env', 'debug', 'osseus_logger', 'osseus_server' ] }

Note that keys starting with "osseus_" are broken into objects, more on this later

AWS Secrets

In order to use AWS Secrets need to define the following variables:

• ENV (or CFG_ENV)
  • no default
• APPLICATION_NAME (or CFG_APPLICATION_NAME)
  • no default
• AWS_SECRETS_ENDPOINT (or CFG_AWS_SECRETS_ENDPOINT)
  • default is https://secretsmanager.eu-west-1.amazonaws.com
• AWS_REGION (or CFG_AWS_REGION)
  • default is eu-west-1

When all relevant variables are defined, the secrets file names should be ENV/APPLICATION_NAME_*

Another secrets file which will be parsed if exists is ENV/GLOBAL_*

Example

Running:

$ export CFG_ENV=QA
$ export CFG_APPLICATION_NAME=MY_APP
$ node index.js

Will look for QA/MY_APP_* and QA/GLOBAL_* in AWS secrets manager and add the keys to the config result object.

CLI arguments

osseus-config is using yargs to parse CLI arguments.

Example

Running:

$ node index.js --PARAM_1 hello --PARAM_2 123 --PARAM_3 ["'something'"]

Will result in:

{ param_1: 'hello',
  param_2: 123,
  param_3: [ 'something' ],
  keys: [ 'param_1', 'param_2', 'param_3' ] }

Parsers Hierarchy

1. CLI arguments
2. AWS Secrets
3. Environment specific files
4. Environment variables

Example

Create /config/LOCAL.js

module.exports = {
  MY_PARAM: from_file
}

Running:

$ export CFG_ENV=LOCAL
$ export CFG_MY_PARAM=from_env
$ node index.js --MY_PARAM from_cli

Will result in:

{ my_param: 'from_cli',
  env: 'LOCAL',
  keys: [ 'my_param', 'env' ] }

Contributing

Please see contributing guidelines.

License

Code released under the MIT License.