map-env-vars v0.2.0

🔗 NPM Package

Map ENV Vars

Fill a variable map with values from ENV vars, selected based on current environment (defaults to process.env.NODE_ENV).

Installation

1. yarn add map-env-vars or npm i map-env-vars

Usage

Let's examine an example:

example.js

import mapEnvVars from 'map-env-vars'

const mappedEnv = mapEnvVars({
  envConfig: {
    'remote_development': 'DEV_',
    'staging': 'STAGE_'
  },
  varLookups: {
    baseUrl: '{ENV}BASE_URL',
    enableDebug: '{ENV}ENABLE_DEBUG',
    host: 'HOST',
    port: 'PORT'
  }
})

console.log(mappedEnv)

For the remote_development environment, ENV variable names are expected to be prefixed with STAGE_ where ever the {ENV} token is used. For the staging environment, ENV variable names are expected to be prefixed with STAGE_ where ever the {ENV} token is used.

This behavior is defined by the key-value pairs of envConfig.

Note that the HOST and PORT ENV variables are searched for directly, without prefix, because the {ENV} token is omitted from their varLookups definition. This behavior also occurs whenever your current execution ENV is not found as a key in the envConfig object. In these cases, the {ENV} token is ignored during lookup.

In a staging NODE_ENV, w/ prefix defined in envConfig options, w/ properly prefixed variable names

NODE_ENV=staging STAGE_BASE_URL=https://test.com STAGE_ENABLE_DEBUG=true HOST=localhost PORT=3000 node index.js

# {
#   "baseUrl": "https://test.com",
#   "enableDebug": "true",
#   "host": "localhost",
#   "port": 3000
# }

In a qa NODE_ENV (not defined in envConfig options)

NODE_ENV=qa BASE_URL=https://test.com ENABLE_DEBUG=true node index.js

# {
#   "baseUrl": "https://test.com",
#   "enableDebug": "true",
#   "host": undefined,
#   "port": undefined
# }

# Note how {ENV} token is ignored when performing lookups. This is because the current
# execution ENV is not found as a key in the envConfig object.
# There are also undefined values here because some ENV values were not set during invocation.

Options

mapEnvVars({
  // defaults to `process.env`
  envData: { myFakeEnvData: true },
  // defaults to `process.env.NODE_ENV`
  envCurrent: 'staging',
  // required
  envConfig: {
    'ENV_ID': 'ENV_REPLACEMENT_'
    // ...
  },
  // required
  varLookups: {
    friendlyVarName: '{ENV}_BIG_SCARY_VAR_NAME'
    // ...
  }
})