Prox Builder - A distributed build server for Caddy binaries

Prox Builder is a build server for Caddy binaries. Currently, Caddy hosts an online build system at https://caddyserver.com/download, however it is a massive piece of infrastructure for them to host freely for everyone wanting custom binary builds.

As a result, I wrote this API-compatible build server that can optionally be distributed horizontally to accommodate a number of custom binary build requests. It can also optionally cache builds to local storage to speed up binary generation times.

Features

• Cache builds locally to quickly service duplicate build requests (Great for CI)
• Delegate builds to multiple agents to maintain throughput in times of high demand
• Stream logs back to the client in realtime - If your build fails due to a broken module, you can quickly pinpoint why
• Select from a number of Caddy base versions - If you're locked to a certain version of Caddy, easily select it as the baseline of your build
• Embedded web UI

Quick Start

Docker

docker build -t proxbuilder:latest .
docker run --rm -it -p 8080:8080 proxbuilder:latest

Docker (docker-compose with a hub, agent and shared redis queue)

docker-compose up

Binaries

TODO

Operating Modes

Prox Builder can operate in a number of modes depending on your scalability and performance needs.

Mode	Command-line Flag	Description
Standalone	(blank)	When neither --hub nor --agent are specified, run the webserver and coordinate the xcaddy builds all in the same process.
Hub	--hub	Run the webserver on this process and dispatch jobs to a redis queue for a number of agents to work in the background. Requires Redis to communicate with build agents.
Agent	--agent	This process will only execute xcaddy builds and copy them to the given storage location after they're done. Requires Redis to receive build jobs from the hub and relay log messages back.

Configuration

Prox Builder can be configured either by specifying command-line flags or by setting environment variables. Environment variables will always take precedence.

Command-line Flag	Environment Variable	Description
--agent	PB_AGENT	This process will only execute xcaddy builds and copy them to the given storage location after they're done.
--hub	PB_HUB	Run the webserver on this process and dispatch jobs to a redis queue for a number of agents to work in the background.
--redis-host	PB_REDIS_HOST	The host to use when connecting to the redis server in hub or agent mode. (Default: localhost)
--redis-port	PB_REDIS_PORT	The port of the redis server in hub or agent mode. (Default: 6379)
--redis-username	PB_REDIS_USERNAME	The username to use when logging into the redis server in hub or agent mode. (Default: blank)
--redis-password	PB_REDIS_PASSWORD	The password to use when logging into the redis server in hub or agent mode. (Default: blank)
--simultaneous-jobs	PB_SIMULTANEOUS_JOBS	The number of concurrent build jobs to run when in agent mode (Default: 2)
--webserver-port	PB_WEBSERVER_PORT	The port to listen on when running in hub or standalone mode (Default: 8080)
--package-endpoint	PB_PACKAGE_ENDPOINT	The endpoint to download the list of caddy modules/packages from (Default: caddyserver.com/api/packages)
--binary-path	PB_BINARY_PATH	The path where newly-built Caddy binaries are stored

API Endpoints

GET /api/download - Build and download a new Caddy server binary

URL parameters are as follows:

Parameter	Description
os	The operating system to build for (e.g., linux, darwin, windows)
arch	The CPU architecture to build for (e.g., amd64, arm64)
p[]	Array of plugin packages to include in the build (e.g., github.com/caddy-dns/cloudflare). Repeat as many times as needed.
caddy_version	The Caddy version to compile against

Things to be done

• Record a local copy of the download numbers rather than simply regurgitating what is in the upstream's /api/packages response payload
• Finish implementing S3 remote storage
• UI fixes for better responsiveness
• Tests