Webhook to PowerShell Healthcheck to ServiceNow Incident

id: servicenow-webhook-powershell-healthcheck
namespace: company.team
description: |
  A webhook receives a VM healthcheck request, Python validates and enriches
  the payload, PowerShell gathers disk metrics, and the results are filed as
  a ServiceNow incident. Failures open a critical incident and ping Slack.

inputs:
  - id: defaultWebhookPayload
    type: JSON
    defaults: |
      { "requestId": "c0271c3c-a256-4e6a-8a63-2a60a2c1b1de", "storeId": "VA-014", "vmName": "retail-edge-va014", "checks": [ "disk" ], "priority": "normal", "requestedBy": "maya.smith@acme-retail.com" }

triggers:
  - id: webhook
    type: io.kestra.plugin.core.trigger.Webhook
    description: POST a healthcheck request payload here to start a run.
    key: "{{ secret('HEALTHCHECK_WEBHOOK_KEY') }}"

tasks:
  - id: validate_payload
    type: io.kestra.plugin.scripts.python.Script
    description: Parse, validate, and enrich the incoming webhook JSON payload.
    dependencies:
      - kestra
    script: |
      from kestra import Kestra
      import json
      from datetime import datetime, timezone

      ALLOWED_CHECKS = {"disk"}
      PRIORITY_TO_SEV = {"low": 4, "normal": 3, "high": 2}

      logger = Kestra.logger()

      def fail(msg):
          logger.error(msg)
          raise RuntimeError(msg)

      def main():
          raw = '''{{ trigger.body ?? '' }}'''
          if not raw:
              logger.warning("Missing trigger payload, using the default payload")
              raw = '''{{ inputs.defaultWebhookPayload }}'''
          try:
              payload = json.loads(raw)
          except Exception:
              fail("Invalid payload JSON")

          for f in ["requestId", "storeId", "vmName", "checks", "priority", "requestedBy"]:
              if f not in payload:
                  fail(f"missing_field:{f}")

          payload["storeId"] = str(payload["storeId"]).strip().upper()

          if not isinstance(payload["checks"], list) or not payload["checks"]:
              fail("checks_must_be_nonempty_list")

          bad = [c for c in payload["checks"] if c not in ALLOWED_CHECKS]
          if bad:
              fail(f"unsupported_checks:{bad}")

          pr = str(payload["priority"]).lower()
          if pr not in PRIORITY_TO_SEV:
              fail("invalid_priority")
          payload["sev"] = PRIORITY_TO_SEV[pr]

          if "@" not in str(payload["requestedBy"]):
              fail("invalid_requestedBy_email")

          payload["receivedAt"] = datetime.now(timezone.utc).isoformat()

          logger.info(f"Validated payload: {payload}")
          Kestra.outputs(payload)

      main()

  - id: run_powershell_commands
    type: io.kestra.plugin.scripts.powershell.Script
    description: Gather cross-platform disk capacity metrics and write a JSON report.
    outputFiles:
      - healthcheck_report.json
    script: |
      param(
        [Parameter(Mandatory=$false)]
        [string]$PayloadJson = '{{ outputs.validate_payload | json }}'
      )

      try {
        $payload = $PayloadJson | ConvertFrom-Json
      } catch {
        $err = [pscustomobject]@{
          ok = $false
          error = "invalid_json"
          detail = $_.Exception.Message
        }
        $err | ConvertTo-Json -Compress
        exit 0
      }

      $doDisk = $true
      if ($payload.PSObject.Properties.Name -contains 'checks') {
        $doDisk = ($payload.checks -contains 'disk')
      }

      $diskMetrics = @()
      if ($doDisk) {
        $drives = [System.IO.DriveInfo]::GetDrives() | Where-Object { $_.IsReady -and ($_.DriveType.ToString() -eq 'Fixed') }
        foreach ($d in $drives) {
          $total = [double]$d.TotalSize
          $free  = [double]$d.AvailableFreeSpace
          $sizeGB = if ($total -gt 0) { [math]::Round($total / 1GB, 2) } else { 0 }
          $freeGB = if ($total -gt 0) { [math]::Round($free  / 1GB, 2) } else { 0 }
          $pctFree = if ($total -gt 0) { [math]::Round(100 * $free / $total, 2) } else { 0 }

          $diskMetrics += [pscustomobject]@{
            drive   = ($d.Name.TrimEnd('\','/'))
            sizeGB  = $sizeGB
            freeGB  = $freeGB
            pctFree = $pctFree
          }
        }
      }

      $advice = if (($diskMetrics | Where-Object { $_.pctFree -lt 15 }).Count -gt 0) {
        "Low free space detected on one or more volumes. Consider cleanup."
      } else {
        "Disk capacity within acceptable thresholds."
      }

      $result = [pscustomobject]@{
        ok         = $true
        kind       = "healthcheck"
        checks     = if ($payload.checks) { $payload.checks } else { @("disk") }
        metrics    = @{ disk = $diskMetrics }
        advice     = $advice
        measuredAt = (Get-Date).ToUniversalTime().ToString("o")
      }
      $jsonOutput = $result | ConvertTo-Json -Depth 6 -Compress

      $jsonOutput | Out-File -FilePath "healthcheck_report.json" -Force

  - id: create_servicenow_incident
    type: io.kestra.plugin.servicenow.Post
    description: File the healthcheck results as a ServiceNow incident.
    domain: "{{ vars.serviceNowInstance }}"
    username: "{{ secret('SERVICENOW_USERNAME') }}"
    password: "{{ secret('SERVICENOW_PASSWORD') }}"
    table: incident
    data:
      short_description: "VM Healthcheck Report for {{ outputs.validate_payload.vars.vmName }}"
      description: |
        Healthcheck performed at {{ outputs.validate_payload.vars.receivedAt }}.
        VM Name: {{ outputs.validate_payload.vars.vmName }}
        Store ID: {{ outputs.validate_payload.vars.storeId }}
        Request ID: {{ outputs.validate_payload.vars.requestId }}

        Advice: {{ outputs.run_powershell_commands.vars }}
      caller_id: "{{ outputs.validate_payload.vars.requestedBy }}"
      priority: "{{ outputs.validate_payload.vars.sev }}"
      category: "Hardware"
      subcategory: "Server"
      contact_type: "Automated Tool"

errors:
  - id: create_servicenow_incident_on_error
    type: io.kestra.plugin.servicenow.Post
    description: Open a critical ServiceNow incident when the flow itself fails.
    domain: "{{ vars.serviceNowInstance }}"
    username: "{{ secret('SERVICENOW_USERNAME') }}"
    password: "{{ secret('SERVICENOW_PASSWORD') }}"
    table: incident
    data:
      short_description: "Kestra Flow Error: {{ flow.id }} (Execution: {{ execution.id }})"
      description: |
        Kestra Flow `{{ flow.namespace }}.{{ flow.id }}` failed.
        Execution ID: `{{ execution.id }}`
        Status: `{{ execution.state }}`
        Error Message: `{{ errorLogs() }}`
        View execution: {{ kestra.url ?? 'http://localhost:8080' }}/ui/executions/{{ flow.namespace }}/{{ flow.id }}/{{ execution.id }}
      caller_id: "kestra-automation@example.com"
      priority: "1"
      category: "Software"
      subcategory: "Application Error"
      contact_type: "Automated Tool"

  - id: send_slack_notification_on_error
    type: io.kestra.plugin.slack.SlackExecution
    description: Ping the on-call channel when the flow fails.
    url: "{{ secret('SLACK_WEBHOOK') }}"
    messageText: |
      Kestra Flow Error
      Flow: `{{ flow.namespace }}.{{ flow.id }}`
      Execution ID: `{{ execution.id }}`
      Status: `{{ execution.state }}`
      Error Message: `{{ errorLogs() }}`
      View execution: {{ kestra.url ?? 'http://localhost:8080' }}/ui/executions/{{ flow.namespace }}/{{ flow.id }}/{{ execution.id }}
    allowFailure: true

variables:
  serviceNowInstance: your-instance