Insights Scheduler Service

(WORK IN PROGRESS)

A Go REST API service for programmatic job scheduling using the declarative shell functional core design pattern.

Architecture

Architecture Diagram

Data flow Diagram

Features

• Functional Core with pure business logic
• Imperative Shell for side effects (HTTP, storage, scheduling)
• CRUD operations for scheduled jobs
• Job control endpoints (run, pause, resume)
• Standard 5-field cron scheduling
• SQLite database storage
• Background job execution

Installation

1. Install dependencies:

go mod tidy

2. Build and run the service:

go run cmd/server/main.go

The service will start on http://localhost:5000 with the scheduler running in the background.

API Endpoints (Work In Progress)

Job Management

• POST /api/scheduler/v1/jobs - Create a new job
• GET /api/scheduler/v1/jobs - Get all jobs (supports ?status= and ?name= filters)
• GET /api/scheduler/v1/jobs/{id} - Get specific job
• PUT /api/scheduler/v1/jobs/{id} - Update job (full replacement)
• PATCH /api/scheduler/v1/jobs/{id} - Partial update job
• DELETE /api/scheduler/v1/jobs/{id} - Delete job

Job Control

• POST /api/scheduler/v1/jobs/{id}/run - Run job immediately
• POST /api/scheduler/v1/jobs/{id}/pause - Pause job
• POST /api/scheduler/v1/jobs/{id}/resume - Resume paused job

Job Runs

• GET /api/scheduler/v1/jobs/{id}/runs - List all runs for a job
• GET /api/scheduler/v1/jobs/{id}/runs/{run_id} - Get specific run details

Job Schema

Jobs are authenticated via the X-Rh-Identity header. The org_id, username, and user_id are automatically extracted from this header and not exposed in API responses.

{
  "id": "string (UUID)",
  "name": "string",
  "schedule": "string (5-field cron expression)",
  "type": "string (message|http_request|command|export)",
  "payload": {},
  "status": "string (scheduled|running|paused|failed)",
  "last_run": "string (ISO timestamp)"
}

Note: The payload field can be any valid JSON value (object, array, string, number, boolean, or null). Its structure depends on the job type.

Schedule Formats

The service accepts standard 5-field cron expressions:

• Format: minute hour day-of-month month day-of-week

Common examples:

• */10 * * * * - Every 10 minutes
• 0 * * * * - Every hour at minute 0
• 0 0 * * * - Every day at midnight
• 0 0 1 * * - Every month on the 1st at midnight
• 30 14 * * MON-FRI - Every weekday at 2:30 PM
• 0 9 * * 1 - Every Monday at 9:00 AM

Testing

Run the test suite:

go run cmd/test/main.go

Make sure the service is running before executing tests.

Architecture (Functional Core / Imperative Shell)

Functional Core (internal/core/)

• domain/ - Pure domain models and validation logic
• usecases/ - Business logic with dependency interfaces

Imperative Shell (internal/shell/)

• http/ - HTTP handlers and routing
• storage/ - In-memory repository implementation
• scheduler/ - Background scheduling
• executor/ - Job execution logic

Entry Points (cmd/)

• server/ - Main application server
• test/ - API test client