Module engine 

The scheduling loop: polls GitHub, pulls the profiles’ images, applies plan’s decisions with GitHub and Docker, removes each runner’s container when its job ends, keeps the mirror up while any runner runs, reseeds idle profiles and recovers runners and containers a previous daemon left. It also feeds the job history: queued jobs, the job each runner took (from observe::capture), steps from GitHub, mirror bytes, cache sizes and slot and budget changes. It owns slot state; it never serves the API (it publishes api::Status and takes commands through Control) and never logs the token or a JIT config.

This module holds Engine‘s state, its construction and its loop; the submodules each add one concern’s methods: recover (startup), tick (polling and planning), runners (a slot’s runner from start to removal), images (pulling the profiles’ images), caches (reseeds, the mirror and the shared caches), build_cache (each runner’s side of the shared build cache and whether its job may write), history (what the store records), warm (how many warm runners each repository wants), control (the API’s commands) and status (what it publishes).

Structs

Commands

The engine’s end of Control’s commands.

Commit

What makes a new config durable, run by the engine before it runs with the config: Ok once the config is in place, with a warning if it may not survive a crash; Err with nothing changed.

Control

Commands from the API and signals to the loop.

Engine

The scheduler with its side effects, on the real GitHub and Docker unless a test passes fakes.

Handle

What the API needs from a running engine.

HostIdentity

This machine as its runner names carry it: runnerd-<id>-<host>-<profile>-<slot>-<secs>. Only runnerd-<id>- identifies the machine, so a changed host name still matches the runners started before the change, and two machines with the same or overlapping host names never take each other’s runners for their own.

Setup

Where the engine runs, besides its config and its GitHub and Docker clients.

Enums

Command

A command the engine carries out between ticks or while a tick waits for GitHub, with where its answer goes.

ControlError

Why the engine refused or failed a command from the API.

RecordSelection

Which records a removal asks for.

RunningJobs

What a pause, a shutdown or a runner’s removal does with the jobs runners are running.

RunningSlots

What a new config may do to slots with a runner in them.

Shutdown

How the daemon is asked to stop.

Target

The repositories a pause or a resume applies to.