Webhook Command Executor with Loki Logging

A lightweight Go service that executes commands via webhooks and streams logs to Grafana Loki in real-time.

Features

• 🚀 Execute commands via simple HTTP webhooks
• 🔍 View last N lines of command output via API
• 📊 Real-time log streaming to Loki (port 3100)
• 🔒 Concurrent execution protection (one instance per command)
• ⚙️ YAML configuration for easy setup
• 📈 Grafana dashboard integration

Installation

Prerequisites

• Go 1.20+
• Grafana Loki (optional)
• Basic terminal knowledge

Quick Start

# Clone the repository
git clone https://github.com/melehin/webhook-executor.git
cd webhook-executor

# Build the binary
go build -o webhook-executor

# Run with default config
./webhook-executor

Configuration

Edit config.yaml to customize your setup:

server:
  port: 9000
  tail:
    lines: 100  # Number of output lines to retain

loki:
  enabled: true
  url: "http://localhost:3100"  # Loki endpoint
  batch_wait_seconds: 2
  batch_size: 100
  timeout_seconds: 10
  labels:
    job: "webhook-server"
    app: "command-executor"
    environment: "production"

hooks:
  - id: redeploy-webhook
    execute-command: "/var/scripts/redeploy.sh"
    command-working-directory: "/var/webhook"
  
  - id: backup-db
    execute-command: "pg_dump -U user mydb | gzip > backup.sql.gz"
    command-working-directory: "/backups"

API Endpoints

Endpoint	Method	Description
/hooks/{hook-id}	GET	Trigger command execution
/tail/{hook-id}	GET	View command status and output
/hooks	GET	List all available hooks

Grafana Integration (optional)

1. Set up Loki datasource in Grafana pointing to your Loki instance
2. Import the dashboard from grafana-dashboard.json
3. Query logs with:

{job="webhook-server", hook_id="redeploy-webhook"}

Security Considerations

1. Run behind a reverse proxy with HTTPS
2. Add authentication middleware
3. Restrict network access to the service
4. Set appropriate file permissions for scripts

Deployment

Systemd Service

# /etc/systemd/system/webhook-executor.service
[Unit]
Description=Webhook Command Executor
After=network.target

[Service]
User=webhook
WorkingDirectory=/opt/webhook-executor
ExecStart=/opt/webhook-executor/webhook-executor
Restart=always

[Install]
WantedBy=multi-user.target

Docker

docker build -t webhook-executor .
docker run -d -p 9000:9000 \
  -v /path/to/config.yaml:/app/config.yaml \
  -v /path/to/scripts:/scripts \
  webhook-executor

Development

# Run tests
go test ./...

# Build with debug symbols
go build -gcflags="all=-N -l" -o webhook-executor-debug

# Format code
go fmt ./...

Tips

1. For production use, consider adding:
   • Request rate limiting
   • JWT authentication
   • Prometheus metrics endpoint
2. Use the command-working-directory to properly scope your commands
3. Test your scripts independently before hooking them up