Dendra Hummingbird Monitor

A lightweight system monitoring agent for Linux servers that collects metrics and sends them to a cloud endpoint (Google BigQuery via Cloud Functions).

• System Metrics: Memory, CPU load, disk usage, network traffic
• Package Management: Tracks installed packages and available updates (supports apt, pacman, dnf, apk, and more via snack)
• Container Monitoring: Docker container stats (CPU, memory, uptime)
• Kubernetes Support: Optional control plane metrics collection
• Low Overhead: Minimal resource usage with configurable collection intervals

• Linux (amd64)
• Go 1.26+ (for building)
• Network access to the metrics endpoint
• Optional: Docker (for container metrics)

# Build for the current system
make

# Build with custom output filename
FILENAME=hummingbird make

# Cross-compile for Linux
GOOS=linux make

Create a configuration file at /etc/dendra/hummingbird.toml:

# Authentication key for the metrics endpoint
authkey = "your-secret-key"

# URL of the metrics ingestion endpoint
endpoint = "https://your-cloud-function-url"

# Network interface names
wan = "eth0"
lan = "eth1"

# Collection interval in minutes
sleeplooptime = 15

1. Build the binary:

   GOOS=linux make

2. Copy to the target server:

   scp dendra-hummingbird-monitor user@server:/usr/local/bin/

3. Create the configuration directory and file:

   ssh user@server "sudo mkdir -p /etc/dendra"
   scp hummingbird.toml user@server:/tmp/
   ssh user@server "sudo mv /tmp/hummingbird.toml /etc/dendra/"

4. Install the systemd service:

   scp dendra-hummingbird-monitor.service user@server:/tmp/
   ssh user@server "sudo mv /tmp/dendra-hummingbird-monitor.service /etc/systemd/system/"
   ssh user@server "sudo systemctl daemon-reload"
   ssh user@server "sudo systemctl enable --now dendra-hummingbird-monitor"

The included dendra-hummingbird-monitor.service file runs the monitor as a system service:

[Unit]
Description=Dendra Hummingbird Monitor
After=network-online.target

[Service]
Type=simple
User=root
ExecStart=/usr/local/bin/dendra-hummingbird-monitor
Restart=always
RestartSec=30

[Install]
WantedBy=multi-user.target

# Start the service
sudo systemctl start dendra-hummingbird-monitor

# Stop the service
sudo systemctl stop dendra-hummingbird-monitor

# Check status
sudo systemctl status dendra-hummingbird-monitor

# View logs
sudo journalctl -u dendra-hummingbird-monitor -f

The metrics are ingested by a Google Cloud Function that writes to BigQuery. See the cloud_function/ directory for the backend implementation.

The Cloud Function requires:

• HUMMINGBIRD_KEY: Authentication key (must match client authkey)

Schema definitions for the BigQuery tables are in cloud_function/bq/:

• metrics_schema.json: Main metrics table
• containers_schema.json: Container metrics
• disk_schema.json: Disk usage metrics

# Show version information and exit
./dendra-hummingbird-monitor --version

# Run as Kubernetes control plane (collects cluster-wide container metrics)
./dendra-hummingbird-monitor --isPrimary

┌─────────────────────┐         ┌─────────────────────┐
│   Linux Server      │         │   Google Cloud      │
│                     │         │                     │
│  ┌───────────────┐  │  POST   │  ┌───────────────┐  │
│  │  Hummingbird  │──┼────────►│  │Cloud Function │  │
│  │    Monitor    │  │         │  └───────┬───────┘  │
│  └───────────────┘  │         │          │          │
│                     │         │          ▼          │
│                     │         │  ┌───────────────┐  │
│                     │         │  │   BigQuery    │  │
│                     │         │  └───────────────┘  │
└─────────────────────┘         └─────────────────────┘

.
├── bin/main.go          # Main entry point
├── config/              # Configuration loading
├── cpu/                 # CPU metrics
├── disk/                # Disk metrics
├── k8s/                 # Kubernetes/Docker integration
├── pkg/                 # Package manager metrics
├── proc/                # /proc filesystem parsing
├── publish/             # HTTP client for posting metrics
├── types/               # Shared data structures
├── cloud_function/      # GCP Cloud Function backend
│   └── bq/              # BigQuery integration
└── wg/                  # WireGuard metrics (if applicable)

# Build and run (requires Linux or cross-compilation)
make
./dendra-hummingbird-monitor

# Run with version info only
./dendra-hummingbird-monitor --version

See repository for license information.