<#
Author: Didier Van Hoye
Date: 2018/09/24
version: 0.9.1
Blog: https://blog.workinghardinit.work
Twitter: @WorkingHardInIT

This PowerShell scripts automated the restart of Tomcat7 when needed. The need is based
it the web servcie running on Tomcat7 returns HTTP status 200 or not.
The work this script does is based on the memo that describe the manual procedure.
It takes away the manual reactive actions that they did multiple days per week, sometimes
multiple times per day

You can register this script as a scheduled task to run every X times.
Below is a example. NOTE LINE WRAPS!!!
Schtasks.exe /CREATE /TN MonitorMyWebService /TR "Powershell.exe C:\SysAdmin\Scripts\MonitorMyWebService.ps1" 
/RU SYSTEM /RL HIGHEST /F /SC DAILY /RI 15 /ST 00:00

Having said that, why on earth over all those years the developers did not find out
what was causing the issue and fixed that beats me. Also since the need to have the catalina
folder deleted for this to work we work under their assumption nothing in there is needed.
This does mean that an "ordinary" restart of the server does not fix any issues with the web service.
So, ideally this script is also run at server startup.

The script logs its findings and actions to a script in the script directory.
#>
$ErrorActionPreference = "Stop"
$FolderToDelete = "C:\Program Files\Apache Software Foundation\Tomcat 7.0\work\Catalina"
$MystatusRunning = 'Running'
$MyStatusStopped = 'Stopped'
$MyService = "Tomcat7"
$MyWebService = "https://mywebservice.company.com/metadatasearch"
$MyWebServiceStatus = 0
$MyServiceCheckLogFile = "MetaDataMonitor"

#region CheckWebServiceStatus 
Function CheckWebService() {
    [CmdletBinding()]
    param(
        [String]$WebService
    )
    try {
        # Create new web request.
        $HTTP_Request = [System.Net.WebRequest]::Create($WebService)

        # WGet a response from the site
        $HTTP_Response = $HTTP_Request.GetResponse()

        # Cast the status of the service to an integer
        $HTTP_Status = [int]$HTTP_Response.StatusCode
 
        If ($HTTP_Status -eq 200) {
            ##Write-Host "All is OK!"
            Return $HTTP_Status
        }
        Else {
            ##Write-Host "The service might be down!"
            Return $HTTP_Status
        }
    
        # Don't litter :-)
        $HTTP_Response.Close()
    }
    
    Catch {
        #Write-Host   $_.Exception.InnerException
        if ($_.Exception.InnerException -contains "The remote server returned an error: (500) Internal Server Error.") {
            $HTTP_Status = [int]500
        }
         else {
           $HTTP_Status = [int]999
         }   
        
        Return $HTTP_Status 
    }
    Finally {

    }
}
#endregion

#region Write-2-Log
function Write-2-Log {
    [CmdletBinding()]
    param(
        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$Message,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [ValidateSet('Information','Warning','Error')]
        [string]$Severity = 'Information'
    )

    $Date = get-date -format "yyyyMMdd"
    [pscustomobject]@{
        Time = (Get-Date -f g)
        Message = $Message
        Severity = $Severity
        
    } | Export-Csv -Path "$PSScriptRoot\$MyServiceCheckLogFile-$Date.log" -Append -NoTypeInformation
}
#endregion

Write-Log -Message "Starting Web Service Status check" -Severity Information
$MyWebServiceStatus = CheckWebService $MyWebService

<#
For some reason once might not be enough
So we strafe them twice - what's worth shooting once is worth shooting twice.
#>

For ($counter = 1; $counter -le 2; $counter++) {

    Try {       
        
        If ($MyWebServiceStatus -ne 200) {
            #Write-Host "The webservice has a problem"
            Write-2-Log -message "The webservice has a problem as it did not return HTTP Status 200" -Severity Warning
            #Stop the TomCat service if it is running
            $ServiceObject = $Null
            $ServiceObject = Get-Service $MyService
            If ($ServiceObject | Where-Object {$_.Status -eq $myStatusRunning}) {
                #Write-Host "Running"
                Write-2-Log -Message "Stopping $MyService ..." -Severity Information
                Stop-Service $MyService
                $ServiceObject.WaitForStatus($MyStatusStopped, "00:00:05")
                #Get-Service $MyService
                Write-2-Log -Message "$MyService has been stopped..." -Severity Information
                #Write-Host "Stopped"
            }

            #Write-Host "Delete folder"
            if (Test-path $FolderToDelete -PathType Container) {    
                #Write-Host Folder Exists
                Write-2-Log -Message "The $FolderToDelete exists ..." -Severity Information
                #Delete the folder & its contents
                Get-ChildItem -Path "$FolderToDelete\\*" -Recurse | Remove-Item -Force -Recurse
                Write-2-Log -Message "$FolderToDelete content has been recursively deleted ..." -Severity Information
                Remove-Item $FolderToDelete -Recurse -force
                Write-2-Log -Message "$FolderToDelete has been deleted ..." -Severity Information
                #Write-Host Folder Deleted
            }

            #Start the TomCat service
            $ServiceObject = $Null
            $ServiceObject = Get-Service $MyService 
            if ($ServiceObject | Where-Object {$_.status -eq $MyStatusStopped} ) {
                        
                Write-2-Log -Message "Starting $MyService ..." -Severity Information
                Start-Service $MyService
                $ServiceObject.WaitForStatus($MyStatusRunning, "00:00:05")
                #Get-Service $MyService
                Write-2-Log -Message "$MyService has been started..." -Severity Information
                #Write-Host Started
            }  
        }       
    }
    catch {
        Write-2-Log -Message "Bailing out of the script due to error" -Severity Warning
        Write-2-Log -Message $_.Exception.Message -Severity Error
        Write-2-Log -Message $_.InvocationInfo.PositionMessage -Severity Error
        Write-2-Log -Message $_.FullyQualifiedErrorID -Severity Error
        Write-2-Log -Message "Stopping Web Service Status check" -Severity Information
    }
    Finally {
        Start-Sleep -Seconds 5
    }    
}