Cron Runner (Rust)

Ultra-light HTTP scheduler in Rust with per-second cron precision.
Adds X-Cron-Secret to every request, supports custom headers and optional body per job.

Features

• 6-field cron expressions (seconds included).
• HTTP methods: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS.
• Per-job headers and body (raw string).
• Minimal sync HTTP client (ureq).
• Structured logs: success (OK) with status, failures (FAIL) with error cause.

Deploy and Host

Use your preferred workflow (Cargo, Docker, or Railway). The service runs as a persistent process and schedules requests internally—no external cron required. When hosting on Railway, set the variables below and deploy in a region close to your target APIs to minimize latency.

Why Deploy

• Replace heavyweight schedulers with a tiny Rust binary.
• Run cron with second-level precision.
• Centralize multiple HTTP jobs (headers, bodies, secrets) in one place.
• Keep simple, transparent logs for success/failure.

Common Use Cases

• Pinging internal or public endpoints on a schedule.
• Triggering background jobs (Laravel/Symfony/NestJS/Rails) via authenticated webhooks.
• Refreshing caches or tokens; pre-warming data.
• Kicking off ETL or status checks at fine-grained intervals.

Environment Variables

• SECRET (required) — shared secret sent as X-Cron-Secret on every request.
• CRON_JOBS (required) — list of jobs separated by ; or new lines.
  Format: METHOD|URL|CRON_EXPR|HEADERS|BODY
  • METHOD: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS
  • URL: full HTTP(S) endpoint (query params allowed)
  • CRON_EXPR: 6-field cron (with seconds)
  • HEADERS (optional): comma-separated Name:Value pairs
  • BODY (optional): raw string payload

Examples

GET|https://httpbingo.org/status/204|0 * * * * *||
POST|https://httpbin.org/post|*/30 * * * * *|Content-Type:application/json|{"ping":true}
PATCH|https://postman-echo.com/patch|15 * * * * *|Authorization:Bearer XYZ,Content-Type:application/json|{"name":"demo"}
DELETE|https://postman-echo.com/delete|45 * * * * *||

Quick Start

Cargo

export SECRET=mysecret
export CRON_JOBS='GET|https://httpbingo.org/status/204|0 * * * * *||;POST|https://httpbin.org/post|*/30 * * * * *|Content-Type:application/json|{"ping":true}'
cargo run --release

Docker

docker build -t cron-runner .
docker run --rm   -e SECRET=mysecret   -e CRON_JOBS='GET|https://httpbingo.org/status/204|0 * * * * *||;POST|https://httpbin.org/post|*/30 * * * * *|Content-Type:application/json|{"ping":true}'   cron-runner

Railway (tips)

• Use Reference Variables to call another service over the private network:
  http://${{service.RAILWAY_PRIVATE_DOMAIN}}:${{service.PORT}}/...
• Private networking avoids public egress and can be safer for service-to-service calls.

Logs

• OK: YYYY-MM-DDTHH:MM:SSZ | OK | METHOD URL | STATUS
• FAIL: YYYY-MM-DDTHH:MM:SSZ | FAIL | METHOD URL | HTTP XXX (client/server error) or transport error.

Tech

• Rust + ureq (sync, minimal) for HTTP.
• cron crate for per-second schedules.