Understanding the Location of config/puma.rb for Puma Configuration

Описание: Learn where to find or place the `config/puma.rb` file for configuring the Puma web server and how Puma loads this configuration.
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This video is based on the question https://stackoverflow.com/q/79348707/ asked by the user 'tscheingeld' ( https://stackoverflow.com/u/5527374/ ) and on the answer https://stackoverflow.com/a/79407592/ provided by the user 'Greg' ( https://stackoverflow.com/u/6307878/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Introduction

When working with Puma, a popular Ruby web server, you may encounter references to a config/puma.rb file in guides or official documentation. This raises the question: Where does this configuration file live?

Where Is config/puma.rb Located?

Puma expects your configuration file to be located relative to the current working directory when you start the server. Specifically, it looks for the configuration in one of these two paths:

config/puma/<environment>.rb (e.g., config/puma/production.rb for the production environment)

config/puma.rb

This search happens inside the directory you are currently in when running the puma command.

Key Points:

The path config/puma.rb is relative to your current directory (often the root of your Rails or Rack-based project).

If you have environment-specific configs, put them in config/puma/<environment>.rb.

If a more specific environment file is missing, Puma falls back to config/puma.rb.

Practical Advice

Place the config/puma.rb file inside the config directory of your project.

When deploying or running Puma, ensure you start it from your project root so it can find the config file correctly.

You can specify a custom config file with the -C or --config flag, e.g., puma -C config/puma.rb.

Conclusion

The config/puma.rb file should reside in your project's config directory and is loaded relative to where you start Puma. This setup allows you to maintain clean and environment-specific settings for your Puma server.



Summary:

config/puma.rb is relative to the current directory when Puma starts.

Puma looks for environment-specific files first, then falls back to config/puma.rb.

Understanding this helps ensure you configure Puma correctly for your application's needs.