lukeb2e / crates-io-proxy

Caching HTTP proxy server for crates.io downloads

Caching HTTP proxy server for crates.io downloads

Introduction

The proxy server listens to HTTP GET requests at /api/v1/crates/{crate}/{version}/download, forwards them to https://crates.io/ and caches the downloaded crates as .crate files on the local filesystem. Subsequent download API hits are serviced using the locally cached crate files.

To use the proxy server, clone and rehost the crates.io index repository from GitHub and change "dl" parameter in config.json file in the repository root to point to the proxy server instead:

{
    "dl": "https://crates-io-proxy.example.com/api/v1/crates",
    "api": "https://crates.io"
}

Cargo can be told to use the package index mirror by using the source replacement feature. Add the following lines to your .cargo/config:

[source.crates-io]
registry = "https://crates-io-mirror.example.com/crates-io-index.git"

Configuration

The proxy server can be configured by either command line options or environment variables.

Run crates-io-proxy --help to get the following help page:

Usage:
    crates-io-proxy [options]

Options:
    -v, --verbose              print more debug info
    -h, --help                 print help and exit
    -V, --version              print version and exit
    -L, --listen ADDRESS:PORT  address and port to listen at (0.0.0.0:3080)
    -U, --upstream-url URL     upstream crates.io URL (https://crates.io/)
    -C, --cache-dir DIR        proxy cache directory (/var/cache/crates-io-proxy)

Environment:
    CRATES_IO_URL              same as --upstream-url option
    CRATES_IO_PROXY_CACHE_DIR  same as --cache-dir option