PowerShell-Toolmaking

1.0.0.16

Chapters/scripting-at-scale/geteventlogs.ps1

#Requires -version 5.0

[cmdletbinding()]
Param(
[Parameter(Position = 0, Mandatory)]
[ValidateNotNullorEmpty()]
[string[]]$Computername,

[ValidateSet("Error","Warning","Information","SuccessAudit","FailureAudit")]
[string[]]$EntryType = @("Error","Warning"),

[ValidateSet("System","Application","Security",
"Active Directory Web Services","DNS Server")]
[string]$Logname = "System",

[datetime]$After = (Get-Date).AddHours(-24),

[Alias("path")]
[string]$OutputPath = "c:\work",

[string]$SendTo
)

#get log data
Write-Host "Gathering $($EntryType -join ",") entries from $logname after $after."  -ForegroundColor cyan

#invoke the command remotely
foreach ($computer in $computername) {
    Write-Host "Querying $computer" -ForegroundColor yellow
}

$data = Invoke-Command {
    Get-EventLog -LogName $using:logname -After $using:after -EntryType $using:entrytype
} -ComputerName $Computername

if ($data) { 
    Write-Host "Creating HTML report" -ForegroundColor Cyan
    #create html report
    $fragments = @()
    $fragments += "<H1>Summary from $After</H1>"
    $fragments += "<H2>Count by server</H2>"
    $fragments += $data | group -Property Machinename  | 
    Sort Count -Descending | Select Count,Name |
    ConvertTo-HTML -As table -Fragment
    $fragments += "<H2>Count by source</H2>"
    $fragments += $data | group -Property source  | 
    Sort Count -Descending | Select Count,Name |
    ConvertTo-HTML -As table -Fragment

    $fragments += "<H2>Detail</H2>"
    $fragments += $data | Select Machinename,TimeGenerated,Source,EntryType,Message |
     ConvertTo-html -as Table -Fragment

# the here string needs to be left justified
$head = @"
<Title>Event Log Summary</Title>
<style>
h2 {
width:95%;
background-color:#7BA7C7;
font-family:Tahoma;
font-size:10pt;
font-color:Black;
}
body { background-color:#FFFFFF;
       font-family:Tahoma;
       font-size:10pt; }
td, th { border:1px solid black;
         border-collapse:collapse; }
th { color:white;
     background-color:black; }
table, tr, td, th { padding: 2px; margin: 0px }
tr:nth-child(odd) {background-color: lightgray}
table { width:95%;margin-left:5px; margin-bottom:20px;}
</style>
"@

    $html = ConvertTo-Html -Body $fragments -PostContent "<h6>$(Get-Date)</h6>" -Head $head

    #save results to a file
    $filename = Join-path -Path $OutputPath -ChildPath "$(Get-Date -UFormat '%Y%m%d_%H%M')_EventlogReport.htm"
    Write-Host "Saving file to $filename" -ForegroundColor Cyan

    Set-content -Path $filename -Value $html -Encoding Ascii

    #email as an html message
    if ($SendTo) {
        $mailparams = @{
            To = $SendTo
            Subject = "Event Log Report" 
            Body = ($html| out-string) 
            BodyAsHtml = $True
        }

        Write-Host "Sending email to $($mailparams.to)" -ForegroundColor green
        Send-MailMessage @mailParams

    } #if $sendto
} #if data
else {
    Write-Host "No matching event entries found." -ForegroundColor Magenta
}