Features

Runner Bootstrap

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Runner Bootstrap

Read when:

  • changing cloud-init;
  • debugging machines that never become SSH-ready;
  • changing the minimal runner contract or readiness checks.

Each runner is an Ubuntu machine prepared by cloud-init. It does not need coordinator credentials.

Bootstrap creates:

  • the crabbox user;
  • SSH key-only access;
  • SSH on the primary port, default 2222, and configured fallback ports, default 22;
  • /work/crabbox;
  • shared package caches.

Bootstrap installs:

  • curl and CA certificates;
  • Git;
  • rsync;
  • jq;
  • OpenSSH server.

Bootstrap intentionally does not install project language runtimes such as Go, Node, pnpm, Docker, databases, or service dependencies. Those belong in GitHub Actions hydration, devcontainers, Nix, mise/asdf, or repository setup scripts. A machine should not pass readiness until crabbox-ready succeeds over SSH.

The CLI prefers the configured SSH port and can fall back through ssh.fallbackPorts during early bootstrap or operator-network egress restrictions. Set ssh.fallbackPorts: [] or CRABBOX_SSH_FALLBACK_PORTS=none when the fallback should be disabled. Long term, snapshots or provider images can replace slow cloud-init once the bootstrap contract is stable.

Related docs: