Multi-stage Dockerfile clones KamadoPool at a pinned SHA, builds
ckpool and kamado-api (with embedded Svelte UI), runtime image
supervises both processes via tini + wait -n. Config covers
bitcoind mainnet/testnet4 variant, payout address, coinbase tag,
vardiff knobs, and log level. Web UI interface only — stratum
:3333 requires a router port-forward or simpleproxy workaround
because StartOS 0.3.x does not forward raw TCP on LAN.
TODO before first build: pin KAMADO_REPO + KAMADO_SHA in the
Dockerfile to a pushed commit.