Discovering the presence of a database in a System Center Powershell script

I’m pretty sure there’s a better way to do this using the native SQL Server management pack but this worked for me (peppered with debugging statements). It looks for a database called staging and if it finds it, it returns the discovery information back.

      <Discovery ID="B.Staging.DiscoverProcessingComponent" Enabled="true" Target="B.Staging.ComputerRole" ConfirmDelivery="true" Remotable="true" Priority="Normal">
        <Category>Discovery</Category>
        <DiscoveryTypes>
          <DiscoveryClass TypeID="B.Staging.ProcessingComponent" />
        </DiscoveryTypes>
        <DataSource ID="PSScript" TypeID="Windows!Microsoft.Windows.TimedPowerShell.DiscoveryProvider">
          <IntervalSeconds>180</IntervalSeconds>
          <SyncTime />
          <ScriptName>DiscoverBStagingProcessingComponent.ps1</ScriptName>
          <ScriptBody><![CDATA[
      param($sourceId, $managedEntityId, $computerName)
      
      $api = New-Object -comObject 'MOM.ScriptAPI'
      $api.LogScriptEvent("Processing discovery",101,2,"Created MOM.ScriptAPI with param sourceId = $sourceId , managedEntityId = $managedEntityId , computerName = $computerName ")
      
      $discoveryData = $api.CreateDiscoveryData(0, $sourceId, $managedEntityId) 
      $api.LogScriptEvent("Processing discovery",101,2,"Executed CreateDiscoveryData")
      
      [system.reflection.assembly]::LoadWithPartialName('Microsoft.SqlServer.SMO') | out-null

      $s=new-object('Microsoft.SqlServer.Management.Smo.Server') $computerName
      $dbs=$s.databases
      $dbs | get-member -membertype property
      $staging = ($dbs | select name | where {$_.name -eq 'staging'})."Name"
      $api.LogScriptEvent("Processing discovery",101,2,"Found anything: $staging")
      
      $instance = $discoveryData.CreateClassInstance("$MPElement[Name='B.Staging.ProcessingComponent']$")
      $api.LogScriptEvent("Processing discovery",101,2,"Executed CreateClassInstance")

      if ($staging -eq 'staging') {
        $instance.AddProperty("$MPElement[Name='Windows!Microsoft.Windows.Computer']/PrincipalName$", $computerName)
        $instance.AddProperty("$MPElement[Name='B.Staging.ProcessingComponent']/B.Staging.ProcessingComponentKey$", "staging")
        
        $api.LogScriptEvent("Processing discovery",101,2,"In the staging branch")

      } else {
          $instance.AddProperty("$MPElement[Name='Windows!Microsoft.Windows.Computer']/PrincipalName$", "")
        $instance.AddProperty("$MPElement[Name='B.Staging.ProcessingComponent']/B.Staging.ProcessingComponentKey$", "")
        
        $api.LogScriptEvent("Processing discovery",101,2,"In the not-staging branch")

      }
      
      $api.LogScriptEvent("Processing discovery",101,2,"About to AddInstance")

      $discoveryData.AddInstance($instance)
      
      $api.LogScriptEvent("Processing discovery",101,2,"About to return discoveryData")

      $discoveryData
      
      ]]></ScriptBody>
          <Parameters>
            <Parameter>
              <Name>sourceID</Name>
              <Value>$MPElement$</Value>
            </Parameter>
            <Parameter>
              <Name>managedEntityID</Name>
              <Value>$Target/Id$</Value>
            </Parameter>
            <Parameter>
              <Name>computerName</Name>
              <Value>$Target/Host/Property[Type="Windows!Microsoft.Windows.Computer"]/PrincipalName$</Value>
            </Parameter>
          </Parameters>
          <TimeoutSeconds>300</TimeoutSeconds>
        </DataSource>
      </Discovery>