feat: add Server / VM Monitor documentation and navigation links

App/FeatureSet/Docs/Content/monitor/server-monitor.md

@@ -0,0 +1,203 @@
+# Server / VM Monitor
+
+Server and VM monitoring allows you to monitor the health and performance of your servers, virtual machines, and other infrastructure by installing a lightweight agent that reports system metrics to OneUptime.
+
+## Overview
+
+Server monitors use an infrastructure agent installed on your servers to collect and report system metrics. This enables you to:
+
+- Monitor server uptime and availability
+- Track CPU, memory, and disk usage
+- Monitor running processes
+- Set alerts based on resource utilization thresholds
+- Detect infrastructure issues before they impact your services
+
+## Creating a Server Monitor
+
+1. Go to **Monitors** in the OneUptime Dashboard
+2. Click **Create Monitor**
+3. Select **Server / VM** as the monitor type
+4. A **Secret Key** will be generated for this monitor — you will need it to configure the agent
+5. Follow the installation instructions to set up the agent on your server
+
+## Installing the Infrastructure Agent
+
+The OneUptime Infrastructure Agent is a lightweight Go-based daemon that collects system metrics and sends them to OneUptime every 30 seconds. It supports Linux, macOS, and Windows.
+
+### Linux / macOS
+
+```bash
+# Install the agent
+curl -sSL https://oneuptime.com/docs/static/scripts/infrastructure-agent/install.sh | sudo bash
+
+# Configure the agent
+sudo oneuptime-infrastructure-agent configure --secret-key=YOUR_SECRET_KEY --oneuptime-url=https://oneuptime.com
+
+# Start the agent
+sudo oneuptime-infrastructure-agent start
+```
+
+Replace `YOUR_SECRET_KEY` with the secret key shown in your monitor's settings, and `https://oneuptime.com` with your OneUptime instance URL if self-hosted.
+
+### Windows
+
+1. Download the latest agent from [GitHub Releases](https://github.com/OneUptime/oneuptime/releases/latest)
+   - `oneuptime-infrastructure-agent_windows_amd64.zip` for x64 systems
+   - `oneuptime-infrastructure-agent_windows_arm64.zip` for ARM64 systems
+2. Extract the zip file
+3. Open Command Prompt as Administrator and run:
+
+```bash
+# Configure the agent
+oneuptime-infrastructure-agent configure --secret-key=YOUR_SECRET_KEY --oneuptime-url=https://oneuptime.com
+
+# Start the agent
+oneuptime-infrastructure-agent start
+```
+
+### Proxy Support
+
+If your server connects to the internet through a proxy, you can configure the agent to use it:
+
+```bash
+sudo oneuptime-infrastructure-agent configure --secret-key=YOUR_SECRET_KEY --oneuptime-url=https://oneuptime.com --proxy-url=http://proxy.example.com:8080
+```
+
+## Agent Commands
+
+The infrastructure agent supports the following commands:
+
+| Command | Description |
+|---------|-------------|
+| `configure` | Configure the agent with your secret key and OneUptime URL |
+| `start` | Start the agent service |
+| `stop` | Stop the agent service |
+| `restart` | Restart the agent service |
+| `status` | Show the current service status |
+| `logs` | View agent logs (use `-n` for line count, `-f` to follow) |
+| `uninstall` | Uninstall the agent service |
+
+## Collected Metrics
+
+The agent collects the following metrics from your server:
+
+### CPU
+
+- **CPU Usage Percent** — Overall CPU utilization as a percentage
+- **CPU Cores** — Number of CPU cores
+
+### Memory
+
+- **Total Memory** — Total available memory
+- **Used Memory** — Memory currently in use
+- **Free Memory** — Available free memory
+- **Memory Usage Percent** — Memory utilization as a percentage
+
+### Disk
+
+For each mounted disk/volume:
+
+- **Total Disk Space** — Total capacity of the disk
+- **Used Disk Space** — Space currently in use
+- **Free Disk Space** — Available free space
+- **Disk Usage Percent** — Disk utilization as a percentage
+- **Disk Path** — Mount path of the disk
+
+### Processes
+
+- **Process Name** — Name of the running process
+- **Process ID (PID)** — Process identifier
+- **Process Command** — Full command used to start the process
+
+## Monitoring Criteria
+
+You can configure criteria to determine when your server is considered online, degraded, or offline.
+
+### Available Check Types
+
+| Check Type | Description |
+|------------|-------------|
+| Is Online | Whether the server agent is reporting (based on heartbeat) |
+| CPU Usage Percent | Current CPU utilization percentage |
+| Memory Usage Percent | Current memory utilization percentage |
+| Disk Usage Percent | Current disk utilization percentage (for a specific disk path) |
+| Server Process Name | Check if a process with a specific name is running |
+| Server Process Command | Check if a process with a specific command is running |
+| Server Process PID | Check if a process with a specific PID is running |
+
+### Filter Types
+
+For numeric metrics (CPU, memory, disk):
+
+- **Greater Than** — Value exceeds a threshold
+- **Less Than** — Value is below a threshold
+- **Greater Than or Equal To** — Value is at or above a threshold
+- **Less Than or Equal To** — Value is at or below a threshold
+- **Evaluate Over Time** — Evaluate using aggregation (Average, Sum, Maximum, Minimum, All Values, Any Value) over a time window
+
+For process checks:
+
+- **Is Executing** — The process is currently running
+- **Is Not Executing** — The process is not running
+
+### Example Criteria
+
+#### Mark server as offline if agent stops reporting
+
+- **Check On**: Is Online
+- **Filter Type**: False
+
+#### Alert when CPU usage exceeds 90%
+
+- **Check On**: CPU Usage Percent
+- **Filter Type**: Greater Than
+- **Value**: 90
+
+#### Alert when disk usage exceeds 85%
+
+- **Check On**: Disk Usage Percent
+- **Disk Path**: `/`
+- **Filter Type**: Greater Than
+- **Value**: 85
+
+#### Alert when memory usage exceeds 80%
+
+- **Check On**: Memory Usage Percent
+- **Filter Type**: Greater Than
+- **Value**: 80
+
+#### Alert if a critical process stops running
+
+- **Check On**: Server Process Name
+- **Filter Type**: Is Not Executing
+- **Value**: `nginx`
+
+## Troubleshooting
+
+### Agent not reporting
+
+- Verify the agent is running: `sudo oneuptime-infrastructure-agent status`
+- Check agent logs: `sudo oneuptime-infrastructure-agent logs -n 50`
+- Confirm the secret key is correct
+- Ensure the server can reach your OneUptime instance URL
+- Check firewall rules allow outbound HTTPS connections
+
+### High resource usage by agent
+
+The agent is designed to be lightweight. If you notice high resource usage:
+- Restart the agent: `sudo oneuptime-infrastructure-agent restart`
+- Check agent logs for errors
+
+### Proxy issues
+
+- Verify the proxy URL and port are correct
+- Ensure the proxy allows connections to your OneUptime instance
+- Reconfigure with: `sudo oneuptime-infrastructure-agent configure --proxy-url=http://proxy:port --secret-key=YOUR_KEY --oneuptime-url=YOUR_URL`
+
+## Best Practices
+
+1. **Set meaningful thresholds** — Configure degraded and offline criteria that match your server's normal operating ranges
+2. **Monitor critical processes** — Use process monitoring to ensure essential services like web servers and databases are always running
+3. **Monitor disk usage proactively** — Disk space issues can cascade into application failures; set alerts well before disks are full
+4. **Use "Evaluate Over Time"** — For metrics like CPU that can spike briefly, use time-based aggregation to avoid false alerts
+5. **Keep the agent updated** — Periodically update the infrastructure agent to get the latest improvements and fixes

App/FeatureSet/Docs/Utils/Nav.ts

@@ -190,6 +190,14 @@ const DocsNav: NavGroup[] = [
         title: "External Status Page Monitor",
         url: "/docs/monitor/external-status-page-monitor",
       },
+      {
+        title: "Server / VM Monitor",
+        url: "/docs/monitor/server-monitor",
+      },
+      {
+        title: "SNMP Monitor",
+        url: "/docs/monitor/snmp-monitor",
+      },
       {
         title: "JavaScript Expressions",
         url: "/docs/monitor/javascript-expression",