Disk Probe

Demonstrates the built‑in disk space probe (auto‑registered) and how to override it with custom thresholds.

Full source

File: pwsh/tutorial/examples/16.6-Health-Disk-Probe.ps1

<#
    Sample:  Disk Probe
    Purpose: Shows the auto-registered disk probe and how to override with custom thresholds.
    File:    16.6-Health-Disk-Probe.ps1
    Notes:   Demonstrates the use of a custom disk probe with specific health thresholds.
#>
param(
    [int]$Port = 5000,
    [IPAddress]$IPAddress = [IPAddress]::Loopback
)

## 1. Logging
New-KrLogger | Add-KrSinkConsole | Register-KrLogger -Name 'console' -SetAsDefault

## 2. Server
New-KrServer -Name 'Health Disk Probe'

## 3. Listener (port 5000)
Add-KrEndpoint -Port $Port -IPAddress $IPAddress

#
# Override disk probe by registering a custom one with same name
## 5. Override auto disk probe with custom logic
Add-KrHealthProbe -Name 'disk' -Tags 'self', 'infra' -ScriptBlock {
    # Simulated values for clarity in documentation (replace with real drive stats if desired)
    $total = 100GB
    $free = 12GB
    $percent = [math]::Round(($free / $total) * 100, 2)
    $status = if ($percent -lt 5) { 'Unhealthy' } elseif ($percent -lt 15) { 'Degraded' } else { 'Healthy' }
    $data = [Collections.Generic.Dictionary[string, object]]::new()
    $data['freePercent'] = $percent
    $data['totalBytes'] = $total
    $data['freeBytes'] = $free
    New-KrProbeResult $status "Free=$percent%" -Data $data
}

## 6. Enable configuration
Enable-KrConfiguration

## 7. Health endpoint
Add-KrHealthEndpoint -Pattern '/healthz' -DefaultTags 'self', 'infra'

## 8. Start server
Start-KrServer -CloseLogsOnExit

Step-by-step

  1. Use the default disk probe or override it by registering a probe with the same name.
  2. Set thresholds for Healthy/Degraded/Unhealthy.
  3. Include percentage and byte metrics in the data for dashboards.
  4. Start the server and query /healthz.

Try It 

Invoke-RestMethod http://127.0.0.1:5005/healthz | ConvertTo-Json -Depth 4

Override Strategy

Use scripted logic to tailor thresholds for specific disks or mount points. You can also add multiple disk probes differentiated by name (e.g., disk-root, disk-data).

Troubleshooting

Symptom Cause Fix
Always Healthy Thresholds too low Tighten degraded/unhealthy cutoffs
Probe missing Override failed Ensure names match (disk)

References

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