Move AWS EventBridge, Cloud Scheduler, and EasyCron onto a runner you own

AWS EventBridge Scheduler, Google Cloud Scheduler, and EasyCron all store the expression, the target URL, and often a bearer token outside your VPC. You pay per invocation or per job cap. Latency includes a hop from their region to yours. When the rule is deleted in the console, the history goes with it.

NexusCron inverts that. The scheduler is a Docker service on the same machine (or the same private network) as the job. SQLite holds definitions and run rows. HTTP fires locally. One payment for NexusCron.

Docker Compose

Deploy next to the app the jobs call. Secrets stay in cron.env.

services:
  nexuscron:
    image: nexuscron:latest
    restart: unless-stopped
    ports:
      - "127.0.0.1:8787:8787"
    environment:
      TZ: UTC
      NEXUSCRON_DATA: /data
      NEXUS_TELEMETRY: "off"
      CRON_ADMIN_TOKEN: ${CRON_ADMIN_TOKEN}
    volumes:
      - ./data:/data
      - ./jobs.json:/app/jobs.json:ro
      - ./cron.env:/run/secrets/env:ro

Map cloud rules to jobs.json

Keep the same cadence. Point HTTP at loopback when the worker is local.

{
  "jobs": [
    {
      "id": "was-eventbridge-invoice-sweep",
      "cron": "0 */6 * * *",
      "timezone": "UTC",
      "http": {
        "url": "http://127.0.0.1:8080/jobs/invoice-sweep",
        "method": "POST",
        "headers": { "Authorization": "Bearer ${INTERNAL_JOB_TOKEN}" }
      },
      "retry": { "max": 3, "backoff_ms": 5000 }
    },
    {
      "id": "was-cloud-scheduler-health",
      "cron": "*/5 * * * *",
      "http": {
        "url": "https://app.yourdomain.com/internal/health",
        "method": "GET"
      }
    }
  ]
}

Cutover

1. Export every cloud timer (expression, URL, headers, timezone).
2. Compose up NexusCron. Hit /health.
3. Load jobs.json. Run one job immediately.
4. Dual-run one interval if the endpoint is idempotent.
5. Disable the EventBridge rule, Cloud Scheduler job, or EasyCron entry.

# Inventory EventBridge / Cloud Scheduler / EasyCron, then:
curl -sS http://127.0.0.1:8787/health
curl -sS -X POST http://127.0.0.1:8787/api/jobs/was-cloud-scheduler-health/run \
  -H "Authorization: Bearer $CRON_ADMIN_TOKEN"
# Dual-run one interval, then disable the cloud rule.

Product page: NexusCron Self-Hosted Task Scheduler. Related: self-hosted cron setup.