git-proxy is a caching proxy for package registries. It sits between
package managers and their upstream repositories, keeps a local copy of
every package it serves, and keeps serving them while the upstream is
unreachable.

It speaks the FreeBSD pkg(8) repository protocol, so a single host can
cache pkg.FreeBSD.org (ports, kmods and pkgbase, for every ABI) and
self-hosted poudriere repositories for a whole network. Repository
catalogues are served byte for byte, so pkg(8) still checks their
signatures against the keys in /usr/share/keys.

It also proxies npm, PyPI, Cargo, RubyGems, Go modules, Maven, Hex,
OCI images, Debian, RPM, Alpine and Arch repositories and more.
