@hyperse-io/hyper-env

Runtime Environment Configuration

Populates your environment from .env files at run-time rather than build-time.

Populates your environment from .env files at run-time rather than build-time.

• Supports multiple .env files.

README

• Examples
• Getting started
• File priority
• Common use cases
  • Environment specific config
  • Specifing an env file
  • Using with Docker entrypoint
• Arguments and parameters

Examples

• Example using Next.js (see README.md)

Getting started

# .env
NEXT_APP_NEXT="Next.js"
NEXT_APP_CRA="Create React App"
NEXT_APP_NOT_SECRET_CODE="1234"

.env file order of priority

We have implemented some sane defaults that have the following order of priority:

1. {path-to-file} // from the --path, -p argument
2. .env.{key} // from the --env, -e argument
3. .env.local
4. .env

Your config is available in process.env on the server. We suggest you add .env.local to .gitignore.

Common use cases

Environment specific config

Frameworks such as Next allow for some nice defaults such as .env.local, .env.production, .env. This has the limitation where you may want to run your app in different environments such as "staging, integration, qa" but still build a "production" app with NODE_ENV=production. With hyper-env this is possible:

# .env.staging
NEXT_APP_API_HOST="api.staging.com"
# .env.production
NEXT_APP_API_HOST="api.production.com"
# .env.qa
NEXT_APP_API_HOST="api.qa.com"
# .env.integration
NEXT_APP_API_HOST="api.integration.com"
# .env.local
NEXT_APP_API_HOST="api.example.dev"
# .env
NEXT_APP_API_HOST="localhost"

for staging you would simply set APP_ENV=staging where you run your app:

{
  ...
  "scripts": {
    "start": "hyper-env --env APP_ENV -- next start" // where .env.${APP_ENV}
  }
  ...
}

Thus NEXT_APP_API_HOST=api.staging.com in your staging environment.

Please keep in mind that you have to pass the name of an environment variable to --env, not the value of it.

• ✔ valid usage (macOS): APP_ENV=staging hyper-env --env APP_ENV -- next start
• ❌ common mistake: hyper-env --env staging -- next start

Specifing an env file

You are also able to specify the path to a specific env file:

{
  ...
  "scripts": {
    "start": "hyper-env --path config/.env.defaults -- next start"
  }
  ...
}

You can use any combination of these two arguments along with the default .env, .env.local to build your runtime config.

Specifing an prefix for white-listed environment variables

You are also able to specify the prefix of white-listed environment variables:

{
  ...
  "scripts": {
    "start": "hyper-env -- next start"
  }
  ...
}

# .env
NEXT_APP_NEXT="Next.js"
NEXT_APP_CRA="Create React App"
NEXT_APP_NOT_SECRET_CODE="1234"

Arguments and parameters

$ hyper-env <args> -- <command>

• <command>

You may pass a command, such as a nodejs entry file to the hyper-env cli tool. For example hyper-scripts, next dev, next start

• --env, -e (default: APP_ENV)

Specify the name of an existing environment variable, whose value is the name of an environment you want, to make hyper-env parse an environment specific env-file. For example, you may set APP_ENV=staging first and then apply --env APP_ENV flag. react-env would load .env.staging, .env.local, .env in that order with the latter taking priority.

• --path, -p (default: '')

Enable debugging for react-env. This will log loaded browser environment variables into your console when running react-env --debug

As a significant breaking change we have dropped the ability to specify specific files via the --env argument. This argument now specifies environment file to be parsed depending on the running environment. For example --env APP_ENV or -e APP_ENV where APP_ENV=staging reads in .env.staging. It is very common for platforms to have staging, qa, integration environments that are still built in "production" mode with NODE_ENV=production. This allows for that usecase and many others.

Depandand command is now in the format hyper-env <args> -- <command>