Hello,
in his office, a customer have a few Avocent KVM switches to control some client computers in a remote room. He ask me about the possibility to get a list of all computers connected to these boxes, because he do not want to maintain any list by hand.
I research the documention but there is no (scripting) interface from which I could get such a list. SSH is only for connecting serial consoles, SNMP offers no OIDs for such a case.
Because of the costs, DSView isn’t a option. The only way seems to be to extracting the list by reading the Webfrontend HTML output. Let us do this 
I wrote a script in powershell, at least version 2 is needed to handle selfsigned SSL certificates, which do the following:
- Login to the Webfronted with https and SSL encryption by System.Net.HTTPWebRequest class to get the authentification cookie
- Get the Device HTML page by .NET class System.Net.Webclient and using Authentification cookie
- Save HTML do a temporary file
- Open the file with Internet Explorer
- Get the URL to start a KVM session, computername and portnumber by DOM
Script details
Define the User, Password, protocol and the devices:
1 2 3 4 5 6 7 8 | # KVM User[string]$sUser="Admin"# KVM Password[string]$sPassword="YourPassword"# Protocol[string]$sProtocol="https"# Your Devices[String[]]$aAvocentDevices=@("Console1.domain.local","Console2.domain.local") |
Built HTTP POST text and disable SSL certificate warnings
1 2 3 4 | [Byte[]]$aBody=[System.Text.Encoding]::Default.GetBytes("action=login&loginUsername="+$sUser+"&loginPassword="+$sPassword+"&language=de")[System.Net.CookieContainer]$oCookieContainer = New-Object System.Net.CookieContainer# Ignore SSL Certificate Warning, requires Powershell 2.0[System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true} |
Built the login POST request by using System.Net.HTTPWebRequest class
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | [string]$sLoginURL = $sProtocol+"://$sConsole/login.php"[System.Net.HTTPWebRequest] $oWebRequest = [System.Net.WebRequest]::create($sLoginURL)$oWebRequest.AllowAutoRedirect = $false$oWebRequest.Method = "POST"$oWebRequest.Accept="application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*"$oWebRequest.Headers.Add("Accept-Encoding: gzip, deflate")$oWebRequest.Headers["Cache-Control"] = "no-cache";$oWebRequest.UserAgent="Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; MS-RTC LM 8; InfoPath.2)"$oWebRequest.ContentType = "application/x-www-form-urlencoded"$oWebRequest.Timeout = ([System.TimeSpan]::FromSeconds(50)).TotalMilliseconds$oWebRequest.CookieContainer = $oCookieContainer$oWebRequest.ContentLength=$aBody.Length$oWebRequest.Referer=$sProtocol+"://$sConsole/login.php"$oWebRequest.CookieContainer.Add((New-Object System.Net.Cookie("/home.php-t1s", "1","","$sConsole"))); |
Getting the authentification cookie and set an avocent specific cookie
1 2 3 4 5 | # Try to login$oReqStream = $oWebRequest.GetRequestStream()$oReqStream.Write($aBody, 0, $aBody.Length)[System.Net.HTTPWebResponse] $oResponse = $oWebRequest.getResponse()$oResponse.Headers["Set-Cookie"]="/home.php-t1s=1;"+$oResponse.Headers["Set-Cookie"] |
Get the device list as html by using the authentification cookie
1 2 3 4 5 6 7 8 9 | $oWebClient = new-object system.net.webclient$oWebClient.Headers.add("Cookie", $oResponse.Headers["Set-Cookie"])$oWebClient.Headers.Add("Accept: application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*")$oWebClient.Headers.Add("Accept-Encoding: text/plain, text/html")# Devicelist as html$sHTML=$oWebClient.DownloadString($sProtocol+"://$sConsole/target-table.php?id=1&colcnt=4")$oReqStream.Flush()$oReqStream.Close()$oResponse.Close() |
Save the HTML Output in a file and open it with Internet Explorer
1 2 3 4 5 6 7 8 9 10 | $sTempFile=[System.IO.Path]::GetTempFileName()+".html"Set-Content -Path $sTempFile $sHTML$oIE=new-object -Com internetexplorer.application$oIE.Visible=1write-host "file:///$sTempFile"$oIE.Navigate2("file:///$sTempFile")while($oIE.busy){ Start-Sleep 1 write-host -nonewline "."} |
Get all devices by DOM (Document object model)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | for($iLoop=1;$iLoop -le 64;$iLoop++){ $oEntry=$oIE.Document.getElementByID("name$iLoop") if($oEntry){ # Valid Entry $sDeviceName=$oEntry.innerHTML write-host "DEVICE: " $sDeviceName $oEntryLink=$oEntry.parentNode $oRegEx=new-object System.Text.RegularExpressions.Regex("targetid=(\d{1,2})$") [Int16]$iTargetID=0 if([System.Int16]::TryParse($oRegEx.Match($oEntryLink.href).Groups[1].Value,[ref]$iTargetID)){ if($iTargetID -gt 0){ $sURL=$sProtocol+"://"+$sConsole+"/session_launch.php?action=connect&sessionType=kvmLaunch&targetId="+$iTargetID.ToString() Write-Host "PORT: " $iTargetID.ToString() write-host "KVM URL: " $sURL } } }} |
Finally quit IE and remove temporary files
1 2 | $oIE.Quit()Remove-Item -Force -Path $sTempFile |
You can download the whole script by opening the post. It should be easy to generate a website with all your devices. Enjoy the script
Michael
I struggled a lot with powershell and fiddler to mimic the login behavior to these avocent devices and was not able to. I did not even thinked the this kind of script will be available on the internet. Thank you very much!!!