src/handler/windows/scripts/log.ps1

$ScriptDirectory = Split-Path $MyInvocation.MyCommand.Path
. (Join-Path $ScriptDirectory helper.ps1)
# all logging settins are here on top

$logLevel = "DEBUG" # ("DEBUG","INFO","WARN","ERROR","FATAL")
$logSize = 1mb # 30kb
$logCount = 10
# end of settings

function Get-LogFile {
 $logDir = Get-Azure-Logs-Path
return "$logDir\es-agent.log"
}
$logFile = Get-LogFile

function Write-Log-Line ($line) {
    Add-Content $logFile -Value $Line
    Write-Host $Line
}

# http://stackoverflow.com/a/38738942
Function Write-Log {
    [CmdletBinding()]
    Param(
    [Parameter(Mandatory=$True)]
    [string]
    $Message,

    [Parameter(Mandatory=$False)]
    [String]
    $Level = "DEBUG"
    )

    $levels = ("DEBUG","INFO","WARN","ERROR","FATAL")
    $logLevelPos = [array]::IndexOf($levels, $logLevel)
    $levelPos = [array]::IndexOf($levels, $Level)
    $Stamp = (Get-Date).toString("yyyy/MM/dd HH:mm:ss:fff")

    if ($logLevelPos -lt 0){
        Write-Log-Line "$Stamp ERROR Wrong logLevel configuration [$logLevel]"
    }

    if ($levelPos -lt 0){
        Write-Log-Line "$Stamp ERROR Wrong log level parameter [$Level]"
    }

    # if level parameter is wrong or configuration is wrong I still want to see the
    # message in log
    if ($levelPos -lt $logLevelPos -and $levelPos -ge 0 -and $logLevelPos -ge 0){
        return
    }

    $Line = "$Stamp $Level $Message"
    Write-Log-Line $Line
}

# https://gallery.technet.microsoft.com/scriptcenter/PowerShell-Script-to-Roll-a96ec7d4
function Reset-Log
{
    # function checks to see if file in question is larger than the paramater specified
    # if it is it will roll a log and delete the oldes log if there are more than x logs.
    param([string]$fileName, [int64]$filesize = 1mb , [int] $logcount = 5)
    $logRollStatus = $true
    if(test-path $filename)
    {
        $file = Get-ChildItem $filename
        if((($file).length) -ige $filesize) #this starts the log roll
        {
            $fileDir = $file.Directory
            #this gets the name of the file we started with
            $fn = $file.name
            $files = Get-ChildItem $filedir | ?{$_.name -like "$fn*"} | Sort-Object lastwritetime
            #this gets the fullname of the file we started with
            $filefullname = $file.fullname
            #$logcount +=1 #add one to the count as the base file is one more than the count
            for ($i = ($files.count); $i -gt 0; $i--)
            {
                #[int]$fileNumber = ($f).name.Trim($file.name) #gets the current number of
                # the file we are on
                $files = Get-ChildItem $filedir | ?{$_.name -like "$fn*"} | Sort-Object lastwritetime
                $operatingFile = $files | ?{($_.name).trim($fn) -eq $i}
                if ($operatingfile)
                 {$operatingFilenumber = ($files | ?{($_.name).trim($fn) -eq $i}).name.trim($fn)}
                else
                {$operatingFilenumber = $null}

                if(($operatingFilenumber -eq $null) -and ($i -ne 1) -and ($i -lt $logcount))
                {
                    $operatingFilenumber = $i
                    $newfilename = "$filefullname.$operatingFilenumber"
                    $operatingFile = $files | ?{($_.name).trim($fn) -eq ($i-1)}
                    write-host "moving to $newfilename"
                    move-item ($operatingFile.FullName) -Destination $newfilename -Force
                }
                elseif($i -ge $logcount)
                {
                    if($operatingFilenumber -eq $null)
                    {
                        $operatingFilenumber = $i - 1
                        $operatingFile = $files | ?{($_.name).trim($fn) -eq $operatingFilenumber}

                    }
                    write-host "deleting " ($operatingFile.FullName)
                    remove-item ($operatingFile.FullName) -Force
                }
                elseif($i -eq 1)
                {
                    $operatingFilenumber = 1
                    $newfilename = "$filefullname.$operatingFilenumber"
                    write-host "moving to $newfilename"
                    move-item $filefullname -Destination $newfilename -Force
                }
                else
                {
                    $operatingFilenumber = $i +1
                    $newfilename = "$filefullname.$operatingFilenumber"
                    $operatingFile = $files | ?{($_.name).trim($fn) -eq ($i-1)}
                    write-host "moving to $newfilename"
                    move-item ($operatingFile.FullName) -Destination $newfilename -Force
                }
            }
          }
         else
         { $logRollStatus = $false}
    }
    else
    {
        $logrollStatus = $false
    }
    $LogRollStatus
}

# to null to avoid output
$Null = @(
    Reset-Log -fileName $logFile -filesize $logSize -logcount $logCount
)