Thruster

Thruster is an HTTP/2 proxy for simple production-ready deployments of Rails applications. It runs alongside the Puma webserver to provide a few additional features to help your app run efficiently and safely on the open Internet:

• Automatic SSL certificate management with Let's Encrypt
• HTTP/2 support
• Basic HTTP caching
• X-Sendfile support for efficient file serving
• Automatic GZIP compression

Thruster tries to be as zero-config as possible, so most features are automatically enabled with sensible defaults.

One exception to that is the SSL_DOMAIN environment variable, which is required to enable SSL provisioning. If SSL_DOMAIN is not set, Thruster will operate in HTTP-only mode.

Installation

Add this line to your application's Gemfile:

gem 'thruster'

Or install it globally:

$ gem install thruster

Usage

To run your Puma application inside Thruster, prefix your usual command string with thrust. For example:

$ thrust bin/rails server

Or with automatic SSL:

$ SSL_DOMAIN=myapp.example.com thrust bin/rails server

Custom configuration

Thruster provides a number of environment variables that can be used to customize its behavior:

Variable Name	Description	Default Value
SSL_DOMAIN	The domain name to use for SSL provisioning. If not set, SSL will be disabled.	None
TARGET_PORT	The port that your Puma server should run on. Thruster will set PORT to this when starting your server.	3000
CACHE_SIZE	The size of the HTTP cache in bytes.	64MB
MAX_CACHE_ITEM_SIZE	The maximum size of a single item in the HTTP cache in bytes.	1MB
X_SENDFILE_ENABLED	Whether to enable X-Sendfile support. Set to 0 or false to disable.	Enabled
MAX_REQUEST_BODY	The maximum size of a request body in bytes. Requests larger than this size will be refused; 0 means no maximum size.	0
STORAGE_PATH	The path to store Thruster's internal state.	./storage/thruster
BAD_GATEWAY_PAGE	Path to an HTML file to serve when the backend server returns a 502 Bad Gateway error. If there is no file at the specific path, Thruster will serve an empty 502 response instead.	./public/502.html
HTTP_PORT	The port to listen on for HTTP traffic.	80
HTTPS_PORT	The port to listen on for HTTPS traffic.	443
HTTP_IDLE_TIMEOUT	The maximum time in seconds that a client can be idle before the connection is closed.	60
HTTP_READ_TIMEOUT	The maximum time in seconds that a client can take to send the request headers.	30
HTTP_WRITE_TIMEOUT	The maximum time in seconds during which the client must read the response.	30