dotenv-schema-rails

dotenv-schema

Dotenv-schema makes dotenv schemaful.

Installation

Write .env and .env_schema:

$ cat .env
DB_HOST=db.example.com
DB_PORT=3306

$ cat .env_schema
DB_HOST:
DB_PORT:

Rails

Add this line to your application's Gemfile:

gem 'dotenv-shcmea-rails'
# DO NOT load dotenv-rails gem! Use dotenv-schema-rails instead.

And then execute:

$ bundle
$ rails server

It fails Dotenv::Schema::ValidationError if the validation failed.

Sinatra or Plain ol' Ruby

$ gem install dotenv

require 'dotenv-schema'
Dotenv.load # raises Dotenv::Schema::ValidationError if the validation failed.

Schema validation rule and .env_schema format

.env_schema is based on YAML format.

Basic rule

It fails validation If any variables which are defined in .env_schema don't exist in .env.

# .env_schema
DB_HOST:
DB_PORT:

# .env
DB_HOST=db.example.com
# => Dotenv::Schema::ValidationError: ENV['DB_PORT'] must exist

It fails validation If any variables which aren't defined in .env_schema exist in .env.

# .env_schema
DB_HOST:

# .env
DB_HOST=db.example.com
DB_PORT=3306
# => Dotenv::Schema::ValidationError: Undefined variable(s): DB_PORT; Please add them into .env_schema

To allow empty string

In default, it fails if any environment variables in .env are empty string.

# .env_schema
DB_HOST:

# .env
DB_HOST=
# => Dotenv::Schema::ValidationError: ENV['DB_HOST'] must not be empty string

You can allow it by using allow_empty_string option.

# .env_schema
DB_HOST:
  allow_empty_string: true

# .env
DB_HOST=
# => Passes validation even though DB_HOST is empty

To allow variables to don't exist

# .env_schema
DB_HOST:
DB_PORT:
  allow_not_exists: true

# .env
DB_HOST=
# => Passes validation even though DB_PORT doesn't exist