cdupuis/sbx-kit-github-yubikey repository overview

Prepares a sandbox for GitHub git over the forwarded host ssh-agent (YubiKey PIV slot 9a, served by docker-piv-agent). The private key and PIN never enter the sandbox — each git network op makes the HOST YubiKey blink for a tap, which the human approves. Pairs with host-side ssh-agent forwarding (the daemon's SSH_AUTH_SOCK at startup). What it does: - network-policy runtime: allow GitHub SSH egress. sbx egress is a TLS-intercepting HTTP(S) proxy, so raw SSH on port 22 is closed at kex by default; this opens it (also covers ssh.github.com:443 for the 443 fallback). - lifecycle startup (idempotent; runs on every boot): accept GitHub's host key on first use (a non-TTY agent can't answer the interactive yes/no prompt), and rewrite any HTTPS github URL to SSH so all git traffic routes through the forwarded agent.