penpot/exporter

Exporter

Node process that renders shapes, frames and files to bitmap, SVG and PDF. It is a consumer: it polls the backend's :exporter job queue on Redis and drives each export through the backend's management API — claim, report the milestones, and settle (complete-job multipart with the artifact, or fail-job on error). There is no HTTP surface of its own and nothing is persisted on this side: the row of the job, its cancel button and its result all live in the backend.

How a job runs

1. The backend dispatcher pushes [job-id, scheduled-at] (JSON) into penpot.worker.queue:<tenant>:exporter.
2. One of the K pollers pops it and owns that connection for the whole run: the blocking pop is both the semaphore of the slot and the backpressure, so the process never runs more exports than pollers. K is PENPOT_EXPORTER_WORKER_CONCURRENCY (default 2, and the browser and wasm pools size themselves to the same figure).
3. The poller claims the job over the management API and, on :run, mints a render session (create-job-session) through which every asset fetch happens as the owner of the job.
4. The milestones are reported as beats (:preparing, :rendering, :packaging, with the objects and pages counters). A watchdog re-sends the last one every second, whatever the run is doing.
5. It settles with complete-job (the artifact rides multipart, the session is closed in the same step) or fail-job. The settle never rejects: a worker that cannot talk leaves the row to the backend's lease GC.

Cancellation

A cancellation reaches the worker through the beats: a skip answer means the backend no longer listens (the row is terminal), so the runner stops between units of work; mid-Skia the watchdog terminates the leased render worker. The row was already cancelled by the backend's cancel-job.

Configuration

Variable	Default	Description
PENPOT_PUBLIC_URI	—	The frontend the assets render through
PENPOT_INTERNAL_URI	public-uri	Same network's frontend; the management API too
PENPOT_REDIS_URI	redis://redis/0	The queue and the rest of redis
PENPOT_TENANT	default	Queue prefix (workspace name in devenv)
PENPOT_EXPORTER_SHARED_KEY	—	The shared key; derived from the secret otherwise
PENPOT_EXPORTER_JOB_TTL	3600	Lifetime of the temp files a job owns, in seconds
PENPOT_EXPORTER_WORKER_CONCURRENCY	2	K: pollers, running exports, pool sizes
PENPOT_WASM_WORKER_POOL_MIN	1	Render workers kept warm; clamped to the max
PENPOT_WASM_WORKER_IDLE_TIMEOUT	300	Silence before a worker is terminated, in seconds
PENPOT_WASM_WORKER_IMAGE_CACHE_SIZE	134217728	Per-worker image cache budget, in bytes

Inspecting the backend

Nothing about a job is stored here: get-job in the backend answers the full row, and its app.debug/admin surfaces render the same records.