Crate runnerd_core 

Domain logic and API types shared by the runnerd daemon and its clients.

api and config build everywhere. The host feature (on by default) adds what only the daemon runs: Docker, the GitHub client, the caches, the scheduler, sizing advice, insights, the job history store and what observes running jobs. Clients depend on this crate without it, and with the client feature for client, their connection to the daemon.

Modules

admission

Admission by measured peaks: a job’s memory peak and average CPU predicted from the job history (Predictor), and the history replayed through admission by caps and by predictions, with or without a CPU budget (simulate), to show what each would have done with the same jobs. Pure: no I/O, no clock.

api

The daemon’s JSON API, version 1: the request and response types every client deserializes, and the principal a transport authenticates. Plain data only: no I/O, no Docker or GitHub types, no secrets but a Pairing’s one-time link, which its Debug leaves out.

buildcache

The build cache every runner shares (ADR 0052, 0053): the entries of Gradle’s HTTP build cache, and of the other tools the runner image points at it, kept per repository in a directory of the daemon’s and served to each runner on a Unix socket of its own, which the runner image forwards to 127.0.0.1. Owns the entries, the size limit, the sockets, and what each runner was served and stored. Which socket a request came in on is who sent it; no job can claim another’s. It never decides whether a job may write: the engine tells it (Writes), from what GitHub says of the job. It never logs a request’s headers, which may carry a tool’s token.

cache

The warm caches runner containers share and keep between jobs: each profile’s read-only snapshot, each slot’s volume (its layers’ changes and its Docker Engine’s data), the shared pnpm store and Maven repository, and the Docker Hub mirror on the runners’ network. Owns their names, mounts and lifecycle; it never decides when a runner starts, and it never touches a volume a running container uses.

config

runnerd.toml: the repositories to serve, the runner profiles they use, the shared caches and the host budget they must fit in. Builds without the host feature, so clients can read a config; its only I/O is reading the file and asking systemctl for a slice’s MemoryMax. It never talks to Docker or GitHub.

docker

Runner containers through the Docker Engine API: the connection, container, volume and image requests, and the DockerApi trait the engine and the caches call. It decides nothing about scheduling, and a JIT config only ever reaches a container as a root-only file, never the create request or a log line.

github

The GitHub REST API as the scheduler and the history need it: queued jobs, a job’s steps, just-in-time runner configs, repository runners and cancelling a run. Owns the token, conditional requests and rate-limit backoff. It must never put the token in a log line, a Debug output or an error, and it decides nothing about scheduling.

insights

Insights from the job history (ADR 0051): jobs that got slower and stayed so, jobs that fail and pass on a re-run, jobs whose memory nears their profile’s cap, jobs that find almost nothing in the build cache, and how long each repository’s jobs wait, this week against the last; and the daily digest. Pure: the daemon reads the history, the config and the clock and passes them in. It sends nothing and changes nothing.

isolation

How a runner container is kept from the host while it runs its own Docker Engine. A backend decides only how the container is created; its name, limits, labels and slice are the same for every backend (docker).

observe

What runnerd learns about running jobs without GitHub’s help: CPU, memory and network of each runner container from its cgroup v2 files and /proc (metrics), the job a runner took and its log from inside the container (capture), and which runner pulled what through the Docker Hub mirror (mirror). Reads files and parses output; it starts no container, writes nothing to the host, and decides nothing about scheduling.

record

Records of failed jobs: which runner containers may be kept, the files a record must never hold, which records go to keep within [records], and what a shell in a record shows first. Pure functions: the engine (scheduler::engine) commits, lists and removes the images, and the daemon serves the shell.

scheduler

Which runners to start and stop, as a pure function of queued jobs, slots, warm runners and the memory and CPU budgets (plan), how many warm runners each repository wants (warm), and the loop that applies those decisions with GitHub and Docker (engine). plan and warm do no I/O and read no clock.

sizing

Right-sizing advice from the job history: the spread of each profile’s and each job’s sampled peaks, waits and slot use, and the memory and slots to set. Pure: the store reads the history, the daemon serves the result (api::Sizing). It never changes the config: a client applies advice through PUT /v1/config, which validates it like any other config, and under [sizing] auto the daemon applies what auto::changes picks the same way.

store

The job history: a SQLite database of jobs, their runners, steps, samples and logs, the events clients resume from, cache sizes, the paused repositories and where the notifier got to. Owns the schema and its migrations, the one writer and the event broadcast. Writes are messages to a writer thread, so the engine never waits on the disk; reads and pruning run on Tokio’s blocking pool, pruning on its own connection, a batch at a time. It decides nothing about scheduling and stores no secret: no token, no JIT config, no runner _diag log.