# Celery Monitoring (Flower)

This directory contains the infrastructure for monitoring Celery tasks across all applications in the cluster using Flower.

## Overview

- **Flower**: Web-based tool for monitoring and administrating Celery clusters
- **Multi-Application**: Monitors both PieFed and BookWyrm Celery tasks
- **Namespace**: `celery-monitoring`
- **URL**: `https://flower.keyboardvagabond.com`

## Components

- `namespace.yaml` - Dedicated namespace for monitoring
- `flower-deployment.yaml` - Flower application deployment
- `service.yaml` - Internal service for Flower
- `ingress.yaml` - External access with TLS and basic auth
- `kustomization.yaml` - Kustomize configuration

## Redis Database Monitoring

Flower monitors multiple Redis databases:
- **Database 0**: PieFed Celery broker
- **Database 3**: BookWyrm Celery broker

## Access & Security

- **Access Method**: kubectl port-forward (local access only)
- **Command**: `kubectl port-forward -n celery-monitoring svc/celery-flower 8080:5555`
- **URL**: http://localhost:8080
- **Security**: No authentication required (local access only)
- **Network Policies**: Cilium policies allow cluster and health check access only

### Port-Forward Setup

1. **Prerequisites**: 
   - Valid kubeconfig with access to the cluster
   - kubectl installed and configured
   - RBAC permissions to create port-forwards in celery-monitoring namespace

2. **Network Policies**: Cilium policies ensure:
   - Port 5555 access from cluster and host (for port-forward)
   - Redis access for monitoring (DB 0 & 3)
   - Cluster-internal health checks

3. **No Authentication Required**: 
   - Port-forward provides secure local access
   - No additional credentials needed

## **🔒 Simplified Security Architecture**

**Current Status**: ✅ **Local access via kubectl port-forward**

### **Security Model**

**1. Local Access Only**
- **Port-Forward**: `kubectl port-forward` provides secure tunnel to the service
- **No External Exposure**: Service is not accessible from outside the cluster
- **Authentication**: Kubernetes RBAC controls who can create port-forwards
- **Encryption**: Traffic encrypted via Kubernetes API tunnel

**2. Network Layer (Cilium Network Policies)**
- **`celery-flower-ingress`**: Allows cluster and host access for port-forward and health checks
- **`celery-flower-egress`**: Restricts outbound to Redis and DNS only
- **DNS Resolution**: Explicit DNS access for service discovery
- **Redis Connectivity**: Targeted access to Redis master (DB 0 & 3)

**3. Pod-Level Security**
- Resource limits (CPU: 500m, Memory: 256Mi)
- Health checks (liveness/readiness probes)
- Non-root container execution
- Read-only root filesystem (where possible)

### **How It Works**
1. **Access Layer**: kubectl port-forward creates secure tunnel via Kubernetes API
2. **Network Layer**: Cilium policies ensure only cluster traffic reaches pods
3. **Application Layer**: Flower connects only to authorized Redis databases
4. **Monitoring Layer**: Health checks ensure service availability
5. **Local Security**: Access requires valid kubeconfig and RBAC permissions

## Features

- **Flower Web UI**: Real-time task monitoring and worker status
- **Prometheus Metrics**: Custom Celery queue metrics exported to OpenObserve
- **Automated Alerts**: Queue size and connection status monitoring
- **Dashboard**: Visual monitoring of queue trends and processing rates

## Monitoring & Alerts

### Metrics Exported

**From Celery Metrics Exporter** (celery-monitoring namespace):
1. **`celery_queue_length`**: Number of pending tasks in each queue
   - Labels: `queue_name`, `database` (piefed/bookwyrm)
   
2. **`redis_connection_status`**: Redis connectivity status (1=connected, 0=disconnected)

3. **`celery_queue_info`**: General information about queue status

**From Redis Exporter** (redis-system namespace):
4. **`redis_list_length`**: General Redis list lengths including Celery queues
5. **`redis_memory_used_bytes`**: Redis memory usage
6. **`redis_connected_clients`**: Number of connected Redis clients
7. **`redis_commands_total`**: Total Redis commands executed

### Alert Thresholds

- **PieFed Warning**: > 10,000 pending tasks
- **PieFed Critical**: > 50,000 pending tasks  
- **BookWyrm Warning**: > 1,000 pending tasks
- **Redis Connection**: Connection lost alert

### OpenObserve Setup

1. **Deploy the monitoring infrastructure**:
   ```bash
   kubectl apply -k manifests/infrastructure/celery-monitoring/
   ```

2. **Import alerts and dashboard**:
   - Access OpenObserve dashboard
   - Import alert configurations from the `openobserve-alert-configs` ConfigMap
   - Import dashboard from the same ConfigMap
   - Configure webhook URLs for notifications

3. **Verify metrics collection**:
   ```sql
   SELECT * FROM metrics WHERE __name__ LIKE 'celery_%' ORDER BY _timestamp DESC LIMIT 10
   ```

### Useful Monitoring Queries

**Current queue sizes**:
```sql
SELECT queue_name, database, celery_queue_length 
FROM metrics 
WHERE _timestamp >= now() - interval '5 minutes' 
GROUP BY queue_name, database 
ORDER BY celery_queue_length DESC
```

**Queue processing rate**:
```sql
SELECT _timestamp, 
       celery_queue_length - LAG(celery_queue_length, 1) OVER (ORDER BY _timestamp) as processing_rate
FROM metrics 
WHERE queue_name='celery' AND database='piefed' 
AND _timestamp >= now() - interval '1 hour'
```
- Queue length monitoring
- Task history and details
- Performance metrics
- Multi-broker support

## Dependencies

- Redis (for Celery brokers)
- kubectl (for port-forward access)
- Valid kubeconfig with cluster access

## Testing & Validation

### Quick Access
```bash
# Start port-forward (runs in background)
kubectl port-forward -n celery-monitoring svc/celery-flower 8080:5555 &

# Access Flower UI
open http://localhost:8080
# or visit http://localhost:8080 in your browser

# Stop port-forward when done
pkill -f "kubectl port-forward.*celery-flower"
```

### Manual Testing Checklist
1. **Port-Forward Access**: ✅ Can access http://localhost:8080 after port-forward
2. **No External Access**: ❌ Service not accessible from outside cluster
3. **Redis Connectivity**: 📊 Shows tasks from both PieFed (DB 0) and BookWyrm (DB 3)
4. **Health Checks**: ✅ Pod shows Ready status
5. **Network Policies**: 🛡️ Egress restricted to DNS and Redis only

### Troubleshooting Commands
```bash
# Check Flower pod status
kubectl get pods -n celery-monitoring -l app.kubernetes.io/name=celery-flower

# View Flower logs
kubectl logs -n celery-monitoring -l app.kubernetes.io/name=celery-flower

# Test Redis connectivity
kubectl exec -n celery-monitoring -it deployment/celery-flower -- wget -qO- http://localhost:5555

# Check network policies
kubectl get cnp -n celery-monitoring

# Test port-forward connectivity
kubectl port-forward -n celery-monitoring svc/celery-flower 8080:5555 --dry-run=client
```

## Deployment

Deployed automatically via Flux GitOps from `manifests/cluster/flux-system/celery-monitoring.yaml`.