flywheel-bootstrap 0.1.0

Bootstrap runner for Flywheel provisioned GPU instances

Bootstrap

This package hosts the BYOC bootstrapper that:

• Ensures Codex is available (prefers release tarball; skips install if already on PATH).
• Fetches the bootstrap payload for a run from the Flywheel backend.
• Launches codex exec with the provided prompt/config and streams logs.
• Collects artifacts (manifest-on-exit) and reports completion or error back to the backend.

Configuration

Bootstrap reads the user's Codex config.toml and requires one of:

[flywheel]
# inline instructions (host-specific tips, paths, sandbox notes)
workspace_instructions = """
Use /mnt/work as your workspace. Write artifacts under ./artifacts.
"""

# or: reference a file (relative paths are resolved against the config file directory)
workspace_instructions_file = "workspace_notes.md"

Rules:

• At least one of workspace_instructions or workspace_instructions_file is required; otherwise bootstrap exits before contacting the server.
• If both are set, the file wins and the inline value is ignored (warns once).
• File contents must be non-empty; the path is resolved relative to the config file if not absolute.

Prompt assembly written to flywheel_prompt.txt:

1. Flywheel engineer context (logging/artifact expectations).
2. Task Description (prompt fetched from the server).
3. Workspace Instructions (resolved from config as above).

Example config: project/bootstrap/examples/config.example.toml can be used as a starting point; update the paths and instructions for your machine.

End-to-end flow (bootstrap.sh → Python bootstrapper)

1. User runs bash ./bootstrap.sh --run-id <id> --token <token> --config /path/to/config.toml [--server <url>] on their BYOC machine.
2. The shim:
   • Ensures uvx is available (installs via https://astral.sh/uv/install.sh if missing, then rechecks PATH with ~/.cargo/bin).
   • Points PKG_PATH to the local repo copy project/bootstrap.
   • Executes uvx --no-cache --from "$PKG_PATH" bootstrap "$@" so the latest local package runs.
3. Python entrypoint (python -m bootstrap):
   • Parses args/env: requires run id + token, required --config, optional --server (default http://localhost:8000).
   • Loads Codex config.toml, enforces presence of workspace instructions (inline or file), extracts workspace/sandbox settings.
4. Workspace resolution:
   • Uses cd/workspace_dir from config if set; otherwise ~/.flywheel/runs/<run_id>.
   • Creates the workspace and validates the artifact manifest path is inside sandbox writable_roots when sandboxing is enabled; else exits with an error.
5. Codex availability:
   • If BOOTSTRAP_MOCK_CODEX is set, skips install and runs a mock flow.
   • Else, if codex is already on PATH, reuse it; otherwise download the Codex release tarball to the workspace/run root and mark it executable.
6. Fetch bootstrap payload:
   • GET <server>/runs/<run_id>/bootstrap with X-Run-Token; payload contains the task prompt.
7. Build prompt file:
   • Combine base Flywheel engineer context, “Task Description” (server prompt), and “Workspace Instructions” (user config) into flywheel_prompt.txt in the workspace.
8. Launch Codex:
   • Run codex exec --json --cd <workspace> --skip-git-repo-check flywheel_prompt.txt with env FLYWHEEL_RUN_ID/TOKEN/SERVER.
   • Start a heartbeat thread posting /runs/{id}/heartbeat every 30s.
   • Stream Codex stdout lines as logs to /runs/{id}/logs; capture Codex run_id if emitted.
9. After Codex exits:
   • Read flywheel_artifacts.json; if empty and Codex run_id is known, attempt one codex resume <id> then re-read.
   • POST artifacts to /runs/{id}/artifacts; POST /complete on exit 0, else /error with the exit code.
   • Stop/join the heartbeat thread.
10. Mock mode (BOOTSTRAP_MOCK_CODEX=1):
    • Sends a heartbeat, a few logs, writes a mock artifact manifest, returns 0 (used in e2e tests).

Next steps

• Publish bootstrap package and switch uvx --from to a release URL.
• Iterate on prompts / general polish