🐧 Linux Agent Setup

Step-by-step guide to install the Monitron Server Agent on a Linux server.

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📋 Prerequisites

• Any Linux distribution (Ubuntu, Debian, CentOS, etc.)
• curl installed (almost always pre-installed)
• bc installed (for math calculations)
• Outbound HTTPS access to your Monitron instance

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📥 Step 1: Download the Agent

# Create a directory for the agent
sudo mkdir -p /opt/monitron

# Copy the agent script (from your Monitron installation's agent/ folder)
sudo cp /path/to/monitron/agent/monitron-agent.sh /opt/monitron/

# Make it executable
sudo chmod +x /opt/monitron/monitron-agent.sh

Or download directly:

sudo curl -o /opt/monitron/monitron-agent.sh https://your-monitron.com/agent/monitron-agent.sh
sudo chmod +x /opt/monitron/monitron-agent.sh

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⚙️ Step 2: Configure

Edit the script to set your Monitron URL and Agent Key:

sudo nano /opt/monitron/monitron-agent.sh

Change these two lines at the top:

MONITRON_URL="https://your-monitron-instance.com"
MONITRON_KEY="your-agent-key-here"

Using Environment Variables (Alternative)

Instead of editing the script, you can set environment variables:

export MONITRON_URL="https://your-monitron-instance.com"
export MONITRON_KEY="your-agent-key-here"

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⏰ Step 3: Set Up Cron

Add a cron entry to run the agent every minute:

sudo crontab -e

Add this line:

* * * * * /opt/monitron/monitron-agent.sh

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✅ Step 4: Verify

Run it manually first:

/opt/monitron/monitron-agent.sh

If it works, you should see the server appear in your Monitron dashboard within a minute.

Check cron is working:

# Wait a minute, then check the Monitron dashboard
# Or check the system log:
grep monitron /var/log/syslog

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🔧 Troubleshooting

Agent not reporting

# Test the script manually
bash -x /opt/monitron/monitron-agent.sh

The -x flag shows each command as it runs, helping you identify issues.

"bc: command not found"

# Ubuntu/Debian
sudo apt install bc

# CentOS/RHEL
sudo yum install bc

curl SSL errors

# If your Monitron instance uses a self-signed certificate
# Add -k flag to curl in the script (not recommended for production)

Permission denied

sudo chmod +x /opt/monitron/monitron-agent.sh

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📊 What Data Looks Like

Here's a sample of what the agent sends:

{
    "agent_key": "your-agent-key",
    "cpu_usage": 23.5,
    "cpu_iowait": 1.2,
    "memory_usage": 67.4,
    "memory_total_mb": 8192,
    "swap_usage": 0,
    "disk_usage": [
        {"mount": "/", "usage": 45, "size": "50G", "used": "22G", "avail": "28G"},
        {"mount": "/home", "usage": 30, "size": "100G", "used": "30G", "avail": "70G"}
    ],
    "network_rx_bytes": 1234567890,
    "network_tx_bytes": 987654321,
    "load_1m": 0.5,
    "load_5m": 0.3,
    "load_15m": 0.2,
    "os": "Ubuntu 24.04 LTS",
    "hostname": "web-server-1",
    "kernel": "6.5.0-44-generic"
}