Lohmann.DotEnv

Loads environment variables from a .env file into your .NET application's process environment variables. Storing configuration in the environment separate from code is based on The Twelve-Factor App methodology.

The .env-file format is compatible to the NodeJS library motdotla/dotenv.

Install

dotnet add package Lohmann.DotEnv

Usage

Default

Create a .env file located right beside your executable:

HOST=api.contoso.com
TOKEN=b3LvpJ7ORbp4qu7P5socUg==

Setup your (console) app to use the .env file:

    class Program
    {
        static void Main(string[] args)
        {
            System.Threading.CancellationTokenSource cts = new System.Threading.CancellationTokenSource();
            System.Console.CancelKeyPress += (s, e) =>
            {
                e.Cancel = true;
                cts.Cancel();
            };

            MainAsync(args, cts.Token).Wait();
        }

        static async Task MainAsync(string[] args, System.Threading.CancellationToken cancellationToken)
        {
            // You load the config off the .env file by issung the LoadAsync method.
            await Lohmann.DotEnv.EnvFile.Default.LoadAsync();

            // You can use the built-in validator to check if all required env variables are set:
            var validationResult = Lohmann.DotEnv.EnvValidator.Default.Validate(new [] { "HOST", "TOKEN" });
            if (validationResult.HasValidationErrors) 
            {
                // ... report errors
                System.Environment.Exit(-1);
            }

            // Now you can access Environment Variables as follows:
            var host = System.Environment.GetEnvironmentVariable("HOST");
            var token = System.Environment.GetEnvironmentVariable("TOKEN");
        }
    }

Customization

• You can override the env file path in the LoadAsync method.
• You can also load the env config from a stream as an LoadAsync overload.
• You can change the error behavior for a missing env file via LoadAsync(throwWhenFileNotExists: false)

FAQ

Should I commit the .env file?

No! - The .env file should only contain environment specific values such as connection strings or tokens. Since these values are extremley sensible, you should never commit them into source control.

License

See LICENSE