Autodiscover a PRTG SNMP Library and add the appropriate sensor via PRTGAPI

Add-PrtgSnmpLibrarySensor.ps1

#requires -module PrtgApi,PowerHtml
function New-PrtgMethodParams {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory)]$Command,
        $Body = ([ordered]@{}),
        $Method = 'GET',
        $client = (Get-PRTGClient),
        [Switch]$NoCredential
    )

    $baseURI = "https://$($client.Server)"
    if (-not $NoCredential) {
        $Body.username = $client.Username
        $Body.passhash = $client.Passhash
    }

    $RequestParams = @{
        Body = $Body
        URI = [URI]::New([URI]$BaseURI,$Command)
        Method = $Method
        UseBasicParsing = $true
        UserAgent = ''
    }

    if ($PRTGWebSessionOut) {
        $GLOBAL:PRTGWebSession = $PrtgWebSessionOut
    }

    if ($GLOBAL:PRTGWebSession) {
        $RequestParams.Websession = $GLOBAL:PRTGWebSession
    } else {
        $RequestParams.SessionVariable = 'PRTGWebsessionOut'
    }

    $RequestParams
}

function Get-PRTGSNMPLibraryOIDLibs {
    $irmParams = New-PrtgMethodParams 'api/sensortypes.json'
    $psl = (irm @irmParams).sensortypes | where id -eq 'snmplibrary' | % preselectionlist
    $pslxml = [xml]([web.httputility]::urldecode($psl))
    $pslxml.select.option.value | where {$psitem}
}

Register-ArgumentCompleter -CommandName Get-PRTGSnmpLibraryTargets -ParameterName OIDLibName -ScriptBlock {Get-PRTGSNMPLibraryOIDLibs}
function Get-PRTGSNMPLibraryTargets {
    [CmdletBinding()]
    param (
        [Parameter(ValueFromPipeline)][PRTGApi.Device]$device,
        [String]$OIDLibName
    )

    $deviceID = $device.Id

    $Body = [ordered]@{
        id = $deviceID
        sensortype = 'snmplibrary_nolist'
        preselection_snmplibrary_nolist = $OIDLibName
    }

    $prtgMethodParams = New-PRTGMethodParams 'controls/addsensor2.htm' -Body $Body 
    $addsensorResult = irm @prtgMethodParams

    if ($addsensorResult -match 'name="tempid" value="(\d+)"') {
        $tmpid = $matches[1]
    } else {
        throw "There was a problem with addsensor2 step"
    }
    
    while (
        -not $nextStepUri
    ) {
        Start-Sleep 1
        $body = [ordered]@{
            id = $deviceID
            tmpid = $tmpid
        }
        $prtgMethodParams = New-PRTGMethodParams 'api/getaddsensorprogress.htm' -NoCredential -Body $Body
        $nextStepUri = (irm @prtgMethodParams).targeturl
    }

    $prtgMethodParams = New-PRTGMethodParams $nextStepUri -NoCredential
    $snmpLibraryResponse = (iwr @prtgMethodParams).rawcontent

    $parsedSnmpLibraryResponse = $snmpLibraryResponse | ConvertFrom-Html
    
    $selectionTable = $parsedSnmpLibraryResponse.SelectSingleNode('//div[@data-caption="Library OIDs"]').SelectSingleNode('//table')
    
    $oidEntries = ($selectionTable.SelectNodes('//tr[td[input[@name="interfacenumber__check"]]]'))
    
    foreach ($oidEntryItem in $oidEntries) { 
        [PSCustomObject][Ordered]@{
            PSTypeName = 'Prtg.SnmpLibraryOidEntry'
            OIDName = $oidEntryItem.InnerText
            TargetValue = $oidEntryItem.childnodes[0].ChildNodes["input"].Attributes["value"].value
            OIDLibName = $OIDLibName
        }
    }
}

function Add-PrtgSnmpLibrarySensor {
    #This function is required because Add-Sensor needs to be able to support 'name' in addition to 'name_'
    [CmdletBinding()]
    param (
        $SnmpLibraryTargets,
        [PrtgAPI.device]$Device,
        [PrtgAPI.Parameters.NewSensorParameters]$SensorParameters
    )

    #Get a HttpValueCollection to build the query with
    #We use this because Invoke-Restmethod with hashtable doesn't support the same key twice so we can't add the multiple library entries
    $snmpTargetQuery = [web.httputility]::ParseQueryString($null)

    #Add the parameters
    $sensorParameters.getParameters()['custom'] | foreach {
        $sensorValue = [string]($PSItem.Value)
        $sensorName = $psItem.Name
    
        if ($PSItem.Name -eq 'library_') {
            $sensorValue = "${sensorValue}$($SnmpLibraryTargets[0].oidlibname)"
        }
    
        if ($PSItem.Name -eq 'name_') {
            $sensorName = 'name'
        }
        
        $snmpTargetQuery.add($sensorName,$sensorValue)
    }

    #Add the OID definitions
    $snmpLibraryTargets.targetvalue.foreach{
        $snmpTargetQuery.add('interfacenumber__check',$PSItem)
    }

    $snmpTargetQuery.add('id',$device.Id)
    $snmpTargetQuery.add('interfacenumber_',1)
    $snmpTargetQuery.add('username',(get-prtgclient).username)
    $snmpTargetQuery.add('passhash',(get-prtgclient).PassHash)
    $snmpTargetQuery.add('sensortype','snmplibrary')


    $addSnmpLibraryUri = 'addsensor5.htm',$snmpTargetQuery.tostring() -join '?' 
    $httpClient = [net.http.httpclient]::new()
    $httpClient.BaseAddress = ([uribuilder]::New('https',(get-prtgclient).server)).uri

    $httpClientResult = $httpclient.GetStringAsync($addSnmpLibraryUri)
}



#region ProofOfConcept
$device = (get-device -id 8322)
$targets = Get-PRTGSNMPLibraryTargets -device $device -OIDLibName 'ads.Talari.oidlib'
$sensorParameters = New-SensorParameters -RawType snmplibrary -device $device
Add-PrtgSnmpLibrarySensor $targets $device $sensorParameters
#endregion ProofOfConcept