refactor(worker): unify port environment variable usage and update deployment docs

Align compute worker to use PORT environment variable consistently across
Dockerfile, docker-compose, and server code, replacing COMPUTE_WORKER_PORT.
Update .env.example and deployment documentation to clarify platform-specific
behavior, especially for Railway and similar environments. This simplifies
configuration and reduces platform-specific issues.

compute/worker/.env.example

@@ -1,6 +1,9 @@
 # Compute worker bind
+# Platform note:
+# - Local/manual: keep PORT=8081
+# - Railway/Render/Fly/etc: platform injects PORT
 COMPUTE_WORKER_HOST=0.0.0.0
-COMPUTE_WORKER_PORT=8081
+PORT=8081
 COMPUTE_LOG_FORMAT=pretty
 # COMPUTE_LOG_LEVEL=info
 

compute/worker/Dockerfile

@@ -22,7 +22,7 @@ WORKDIR /workspace
 COPY --from=deploy-stage /opt/compute-worker ./
 
 ENV COMPUTE_WORKER_HOST=0.0.0.0
-ENV COMPUTE_WORKER_PORT=8081
+ENV PORT=8081
 
 EXPOSE 8081
 

compute/worker/docker-compose.yml

@@ -21,7 +21,7 @@ services:
     environment:
       NATS_URL: ${NATS_URL:-nats://nats:4222}
       COMPUTE_WORKER_HOST: ${COMPUTE_WORKER_HOST:-0.0.0.0}
-      COMPUTE_WORKER_PORT: ${COMPUTE_WORKER_PORT:-8081}
+      PORT: ${PORT:-8081}
       COMPUTE_WORKER_TOKEN: ${COMPUTE_WORKER_TOKEN:-local-compute-token}
       S3_PREFIX: ${S3_PREFIX:-openreader}
       COMPUTE_PREWARM_MODELS: ${COMPUTE_PREWARM_MODELS:-true}

compute/worker/src/server.ts

@@ -422,8 +422,7 @@ async function createWorkerLoop<TPayload, TResult>(input: {
 }
 
 async function main(): Promise<void> {
-  const platformPort = readIntEnv('PORT', 8081);
-  const port = readIntEnv('COMPUTE_WORKER_PORT', platformPort);
+  const port = readIntEnv('PORT', 8081);
   const host = process.env.COMPUTE_WORKER_HOST?.trim() || '0.0.0.0';
   const workerToken = requireEnv('COMPUTE_WORKER_TOKEN');
   const natsUrl = requireEnv('NATS_URL');

docs-site/docs/deploy/compute-worker.md

@@ -42,7 +42,7 @@ Common optional:
 - `S3_FORCE_PATH_STYLE=true` (for many S3-compatible providers)
 - `S3_PREFIX=openreader`
 - `COMPUTE_WORKER_HOST=0.0.0.0`
-- `COMPUTE_WORKER_PORT=8081`
+- `PORT=8081` (local/manual; on Railway platform injects this)
 - `COMPUTE_LOG_FORMAT=pretty` (default) or `json`
 - `COMPUTE_PREWARM_MODELS=true`
 - `COMPUTE_JOBS_STREAM_MAX_BYTES=268435456` (256MB JetStream jobs stream cap)
@@ -54,7 +54,10 @@ Set on the Next.js app server:
 
 ```env
 COMPUTE_MODE=worker
-COMPUTE_WORKER_URL=http://<worker-host>:8081
+# Local worker example:
+# COMPUTE_WORKER_URL=http://localhost:8081
+# Cloud worker example (Railway):
+COMPUTE_WORKER_URL=https://<railway-worker-domain>
 COMPUTE_WORKER_TOKEN=<same-token-as-worker>
 ```
 
@@ -94,7 +97,8 @@ Create a Railway service from:
 ghcr.io/richardr1126/openreader-compute-worker:refactor-ppdoclayoutv3-onnx-layout-parsing
 ```
 
-Set the container port to `8081`, then enable public networking to get a worker URL.
+Railway injects a dynamic `PORT` env var and routes traffic there.
+Do not hardcode Railway ingress to `8081`; keep service networking enabled and use the public Railway URL.
 
 ### 3. Configure Railway worker environment variables
 
@@ -102,7 +106,9 @@ Set these in the Railway worker service:
 
 ```env
 COMPUTE_WORKER_HOST=0.0.0.0
-COMPUTE_WORKER_PORT=8081
+# Local/manual only:
+# PORT=8081
+# Railway: rely on injected PORT
 COMPUTE_WORKER_TOKEN=<long-random-shared-token>
 COMPUTE_JOBS_STREAM_MAX_BYTES=268435456
 COMPUTE_JOB_STATES_MAX_BYTES=67108864
@@ -125,6 +131,7 @@ Notes:
 
 - `NATS_CREDS` should be the full Synadia `.creds` file content, including begin/end markers.
 - Keep `COMPUTE_WORKER_TOKEN` identical between app server and worker.
+- On Railway, leave `PORT` managed by the platform.
 - If your platform supports mounted files, you can use `NATS_CREDS_FILE` instead of `NATS_CREDS`.
 - `COMPUTE_JOBS_STREAM_MAX_BYTES` and `COMPUTE_JOB_STATES_MAX_BYTES` are optional; defaults are `268435456` (256MiB) and `67108864` (64MiB).