DSCResources/DSC_IisLogging/DSC_IisLogging.psm1

$modulePath = Join-Path -Path (Split-Path -Path (Split-Path -Path $PSScriptRoot -Parent) -Parent) -ChildPath 'Modules'

# Import the WebAdministrationDsc Common Modules
Import-Module -Name (Join-Path -Path $modulePath `
        -ChildPath (Join-Path -Path 'WebAdministrationDsc.Common' `
            -ChildPath 'WebAdministrationDsc.Common.psm1'))

Import-Module -Name (Join-Path -Path $modulePath -ChildPath 'DscResource.Common')

# Import Localization Strings
$script:localizedData = Get-LocalizedData -DefaultUICulture 'en-US'
<#
    .SYNOPSIS
        This will return a hashtable of results about the given LogPath
#>

function Get-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [Parameter(Mandatory = $true)]
        [String] $LogPath
    )

    Assert-Module -ModuleName WebAdministration

    $currentLogSettings = Get-WebConfiguration `
        -filter '/system.applicationHost/sites/siteDefaults/Logfile'

    Write-Verbose -Message ($script:localizedData.VerboseGetTargetResult)

    $cimLogCustomFields = @(ConvertTo-CimLogCustomFields -InputObject $currentLogSettings.logFile.customFields.Collection)

    $logFlagsArray = $null
    if ($currentLogSettings.LogExtFileFlags -is [System.String])
    {
        $logFlagsArray = [System.String[]] $currentLogSettings.LogExtFileFlags.Split(',')
    }

    return @{
        LogPath              = $currentLogSettings.directory
        LogFlags             = $logFlagsArray
        LogPeriod            = $currentLogSettings.period
        LogTruncateSize      = $currentLogSettings.truncateSize
        LoglocalTimeRollover = $currentLogSettings.localTimeRollover
        LogFormat            = $currentLogSettings.logFormat
        LogTargetW3C         = $currentLogSettings.logTargetW3C
        LogCustomFields      = $cimLogCustomFields
    }
}

<#
    .SYNOPSIS
        This will set the desired state

    .PARAMETER LogPath
        Path to the logfile

    .PARAMETER LogFlags
        Specifies flags to check
        Limited to the set: ('Date','Time','ClientIP','UserName','SiteName','ComputerName','ServerIP','Method','UriStem','UriQuery','HttpStatus','Win32Status','BytesSent','BytesRecv','TimeTaken','ServerPort','UserAgent','Cookie','Referer','ProtocolVersion','Host','HttpSubStatus')

    .PARAMETER LogPeriod
        Specifies the log period.
        Limited to the set: ('Hourly','Daily','Weekly','Monthly','MaxSize')

    .PARAMETER LogTruncateSize
        Specifies log truncate size
        Limited to the range (1048576 - 4294967295)

    .PARAMETER LoglocalTimeRollover
        Sets log local time rollover

    .PARAMETER LogFormat
        Specifies log format
        Limited to the set: ('IIS','W3C','NCSA')

    .PARAMETER LogTargetW3C
        Specifies W3C log format
        Limited to the set: ('File','ETW','File,ETW')

    .PARAMETER LogCustomField
        A CimInstance collection of what state the LogCustomField should be.

#>

function Set-TargetResource
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [String] $LogPath,

        [Parameter()]
        [ValidateSet('Date', 'Time', 'ClientIP', 'UserName', 'SiteName', 'ComputerName', 'ServerIP', 'Method', 'UriStem', 'UriQuery', 'HttpStatus', 'Win32Status', 'BytesSent', 'BytesRecv', 'TimeTaken', 'ServerPort', 'UserAgent', 'Cookie', 'Referer', 'ProtocolVersion', 'Host', 'HttpSubStatus')]
        [String[]] $LogFlags,

        [Parameter()]
        [ValidateSet('Hourly', 'Daily', 'Weekly', 'Monthly', 'MaxSize')]
        [String] $LogPeriod,

        [Parameter()]
        [ValidateScript({
            ([ValidateRange(1048576, 4294967295)] $valueAsUInt64 = [UInt64]::Parse($_))
        })]
        [String] $LogTruncateSize,

        [Parameter()]
        [Boolean] $LoglocalTimeRollover,

        [Parameter()]
        [ValidateSet('IIS', 'W3C', 'NCSA')]
        [String] $LogFormat,

        [Parameter()]
        [ValidateSet('File', 'ETW', 'File,ETW')]
        [String] $LogTargetW3C,

        [Parameter()]
        [Microsoft.Management.Infrastructure.CimInstance[]]
        $LogCustomFields
    )

    Assert-Module -ModuleName WebAdministration

    $currentLogState = Get-TargetResource -LogPath $LogPath

    # Update LogFormat if needed
    if ($PSBoundParameters.ContainsKey('LogFormat') -and `
        ($LogFormat -ne $currentLogState.LogFormat))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogFormat)
        Set-WebConfigurationProperty '/system.applicationHost/sites/siteDefaults/logfile' `
            -Name logFormat `
            -Value $LogFormat
    }

    # Update LogPath if needed
    if ($PSBoundParameters.ContainsKey('LogPath') -and ($LogPath -ne $currentLogState.LogPath))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogPath)
        Set-WebConfigurationProperty '/system.applicationHost/sites/siteDefaults/logfile' `
            -Name directory `
            -Value $LogPath
    }

    # Update Logflags if needed; also sets logformat to W3C
    if ($PSBoundParameters.ContainsKey('LogFlags') -and `
        (-not (Compare-LogFlags -LogFlags $LogFlags)))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogFlags)
        Set-WebConfigurationProperty '/system.Applicationhost/Sites/SiteDefaults/logfile' `
            -Name logFormat `
            -Value 'W3C'
        Set-WebConfigurationProperty '/system.Applicationhost/Sites/SiteDefaults/logfile' `
            -Name logExtFileFlags `
            -Value ($LogFlags -join ',')
    }

    # Update Log Period if needed
    if ($PSBoundParameters.ContainsKey('LogPeriod') -and `
        ($LogPeriod -ne $currentLogState.LogPeriod))
    {
        if ($PSBoundParameters.ContainsKey('LogTruncateSize'))
        {
            Write-Verbose -Message ($script:localizedData.WarningLogPeriod)
        }
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogPeriod)
        Set-WebConfigurationProperty '/system.Applicationhost/Sites/SiteDefaults/logfile' `
            -Name period `
            -Value $LogPeriod
    }

    # Update LogTruncateSize if needed
    if ($PSBoundParameters.ContainsKey('LogTruncateSize') -and `
        ($LogTruncateSize -ne $currentLogState.LogTruncateSize))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogTruncateSize)
        Set-WebConfigurationProperty '/system.Applicationhost/Sites/SiteDefaults/logfile' `
            -Name truncateSize `
            -Value $LogTruncateSize
        Set-WebConfigurationProperty '/system.Applicationhost/Sites/SiteDefaults/logfile' `
            -Name period `
            -Value 'MaxSize'
    }

    # Update LoglocalTimeRollover if needed
    if ($PSBoundParameters.ContainsKey('LoglocalTimeRollover') -and `
        ($LoglocalTimeRollover -ne `
            ([System.Convert]::ToBoolean($currentLogState.LoglocalTimeRollover))))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLoglocalTimeRollover)
        Set-WebConfigurationProperty '/system.Applicationhost/Sites/SiteDefaults/logfile' `
            -Name localTimeRollover `
            -Value $LoglocalTimeRollover
    }

    # Update LogTargetW3C if needed
    if ($PSBoundParameters.ContainsKey('LogTargetW3C') -and `
        ($LogTargetW3C -ne $currentLogState.LogTargetW3C))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogTargetW3C)
        Set-WebConfigurationProperty '/system.applicationHost/sites/siteDefaults/logfile' `
            -Name logTargetW3C `
            -Value $LogTargetW3C
    }

    # Update LogCustomFields if needed
    if ($PSBoundParameters.ContainsKey('LogCustomFields') -and `
        (-not (Test-LogCustomField -LogCustomField $LogCustomFields)))
    {
        Write-Verbose -Message ($script:localizedData.VerboseSetTargetUpdateLogCustomFields)

        Set-LogCustomField -LogCustomField $LogCustomFields
    }
}

<#
    .SYNOPSIS
        This tests the desired state. If the state is not correct it will return $false.
        If the state is correct it will return $true

    .PARAMETER LogPath
        Path to the logfile

    .PARAMETER LogFlags
        Specifies flags to check
        Limited to the set: ('Date','Time','ClientIP','UserName','SiteName','ComputerName','ServerIP','Method','UriStem','UriQuery','HttpStatus','Win32Status','BytesSent','BytesRecv','TimeTaken','ServerPort','UserAgent','Cookie','Referer','ProtocolVersion','Host','HttpSubStatus')

    .PARAMETER LogPeriod
        Specifies the log period.
        Limited to the set: ('Hourly','Daily','Weekly','Monthly','MaxSize')

    .PARAMETER LogTruncateSize
        Specifies log truncate size
        Limited to the range (1048576 - 4294967295)

    .PARAMETER LoglocalTimeRollover
        Sets log local time rollover

    .PARAMETER LogFormat
        Specifies log format
        Limited to the set: ('IIS','W3C','NCSA')

    .PARAMETER LogTargetW3C
        Specifies W3C log format
        Limited to the set: ('File','ETW','File,ETW')

    .PARAMETER LogCustomField
        A CimInstance collection of what state the LogCustomField should be.

#>

function Test-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [String] $LogPath,

        [Parameter()]
        [ValidateSet('Date', 'Time', 'ClientIP', 'UserName', 'SiteName', 'ComputerName', 'ServerIP', 'Method', 'UriStem', 'UriQuery', 'HttpStatus', 'Win32Status', 'BytesSent', 'BytesRecv', 'TimeTaken', 'ServerPort', 'UserAgent', 'Cookie', 'Referer', 'ProtocolVersion', 'Host', 'HttpSubStatus')]
        [String[]] $LogFlags,

        [Parameter()]
        [ValidateSet('Hourly', 'Daily', 'Weekly', 'Monthly', 'MaxSize')]
        [String] $LogPeriod,

        [Parameter()]
        [ValidateScript({
            ([ValidateRange(1048576, 4294967295)] $valueAsUInt64 = [UInt64]::Parse($_))
        })]
        [String] $LogTruncateSize,

        [Parameter()]
        [Boolean] $LoglocalTimeRollover,

        [Parameter()]
        [ValidateSet('IIS', 'W3C', 'NCSA')]
        [String] $LogFormat,

        [Parameter()]
        [ValidateSet('File', 'ETW', 'File,ETW')]
        [String] $LogTargetW3C,

        [Parameter()]
        [Microsoft.Management.Infrastructure.CimInstance[]]
        $LogCustomFields
    )

    Assert-Module -ModuleName WebAdministration

    $currentLogState = Get-TargetResource -LogPath $LogPath

    # Check LogFormat
    if ($PSBoundParameters.ContainsKey('LogFormat'))
    {
        # Warn if LogFlags are passed in and Current LogFormat is not W3C
        if ($PSBoundParameters.ContainsKey('LogFlags') -and `
                $LogFormat -ne 'W3C')
        {
            Write-Verbose -Message ($script:localizedData.WarningIncorrectLogFormat)
        }

        # Warn if LogFlags are passed in and Desired LogFormat is not W3C
        if ($PSBoundParameters.ContainsKey('LogFlags') -and `
                $currentLogState.LogFormat -ne 'W3C')
        {
            Write-Verbose -Message ($script:localizedData.WarningIncorrectLogFormat)
        }

        # Check LogFormat
        if ($LogFormat -ne $currentLogState.LogFormat)
        {
            Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLogFormat)
            return $false
        }
    }

    # Check LogFlags
    if ($PSBoundParameters.ContainsKey('LogFlags') -and `
        (-not (Compare-LogFlags -LogFlags $LogFlags)))
    {
        Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLogFlags)
        return $false
    }

    # Check LogPath
    if ($PSBoundParameters.ContainsKey('LogPath') -and `
        ($LogPath -ne $currentLogState.LogPath))
    {
        Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLogPath)
        return $false
    }

    # Check LogPeriod
    if ($PSBoundParameters.ContainsKey('LogPeriod') -and `
        ($LogPeriod -ne $currentLogState.LogPeriod))
    {
        if ($PSBoundParameters.ContainsKey('LogTruncateSize'))
        {
            Write-Verbose -Message ($script:localizedData.WarningLogPeriod)
        }

        Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLogPeriod)
        return $false
    }

    # Check LogTruncateSize
    if ($PSBoundParameters.ContainsKey('LogTruncateSize') -and `
        ($LogTruncateSize -ne $currentLogState.LogTruncateSize))
    {
        Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLogTruncateSize)
        return $false
    }

    # Check LoglocalTimeRollover
    if ($PSBoundParameters.ContainsKey('LoglocalTimeRollover') -and `
        ($LoglocalTimeRollover -ne `
            ([System.Convert]::ToBoolean($currentLogState.LoglocalTimeRollover))))
    {
        Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLoglocalTimeRollover)
        return $false
    }

    # Check LogTargetW3C
    if ($PSBoundParameters.ContainsKey('LogTargetW3C') -and `
        ($LogTargetW3C -ne $currentLogState.LogTargetW3C))
    {
        Write-Verbose -Message ($script:localizedData.VerboseTestTargetFalseLogTargetW3C)
        return $false
    }

    # Check LogCustomFields if needed
    if ($PSBoundParameters.ContainsKey('LogCustomFields') -and `
        (-not (Test-LogCustomField -LogCustomField $LogCustomFields)))
    {
        Write-Verbose -Message ($script:localizedData.VerboseTestTargetUpdateLogCustomFields)
        return $false
    }

    return $true

}

#region Helper functions

<#
    .SYNOPSIS
        Helper function used to validate the logflags status.
        Returns False if the loglfags do not match and true if they do

    .PARAMETER LogFlags
        Specifies flags to check
#>

function Compare-LogFlags
{
    [CmdletBinding()]
    [OutputType([Boolean])]
    param
    (
        [Parameter()]
        [ValidateSet('Date', 'Time', 'ClientIP', 'UserName', 'SiteName', 'ComputerName', 'ServerIP', 'Method', 'UriStem', 'UriQuery', 'HttpStatus', 'Win32Status', 'BytesSent', 'BytesRecv', 'TimeTaken', 'ServerPort', 'UserAgent', 'Cookie', 'Referer', 'ProtocolVersion', 'Host', 'HttpSubStatus')]
        [String[]] $LogFlags
    )

    $currentLogFlags = (Get-WebConfigurationProperty `
        -Filter '/system.Applicationhost/Sites/SiteDefaults/logfile' `
        -Name LogExtFileFlags) -split ',' | `
        Sort-Object

    $proposedLogFlags = $LogFlags -split ',' | Sort-Object

    if (Compare-Object -ReferenceObject $currentLogFlags `
        -DifferenceObject $proposedLogFlags)
    {
        return $false
    }

    return $true

}
<#
    .SYNOPSIS
        Converts IIS custom log field collection to instances of the DSC_LogCustomField CIM class.

    .PARAMETER InputObject
        Specifies input object passed in

#>

function ConvertTo-CimLogCustomFields
{
    [CmdletBinding()]

    [OutputType([Microsoft.Management.Infrastructure.CimInstance])]
    param
    (
        [Parameter(Mandatory = $true)]
        [AllowEmptyCollection()]
        [AllowNull()]
        [Object[]] $InputObject
    )

    $cimClassName = 'DSC_LogCustomField'
    $cimNamespace = 'root/microsoft/Windows/DesiredStateConfiguration'
    $cimCollection = New-Object -TypeName 'System.Collections.ObjectModel.Collection`1[Microsoft.Management.Infrastructure.CimInstance]'

    foreach ($customField in $InputObject)
    {
        $cimProperties = @{
            LogFieldName = $customField.LogFieldName
            SourceName   = $customField.SourceName
            SourceType   = $customField.SourceType
        }

        $cimCollection += (New-CimInstance -ClassName $cimClassName `
            -Namespace $cimNamespace `
            -Property $cimProperties `
            -ClientOnly)
    }

    return $cimCollection
}

<#
    .SYNOPSIS
        Helper function used to set the LogCustomField for a website.

    .PARAMETER LogCustomField
        A CimInstance collection of what the LogCustomField should be.
#>

function Set-LogCustomField
{
    [CmdletBinding()]
    param
    (

        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [Microsoft.Management.Infrastructure.CimInstance[]]
        $LogCustomField
    )

    $setCustomFields = @()

    foreach ($customField in $LogCustomField)
    {
        if ($customField.Ensure -ne 'Absent')
        {
            $setCustomFields += @{
                logFieldName = $customField.LogFieldName
                sourceName   = $customField.SourceName
                sourceType   = $customField.SourceType
            }
        }
    }

    <#
        Set-WebConfigurationProperty updates logfile.customFields.
    #>


    Set-WebConfigurationProperty -PSPath 'MACHINE/WEBROOT/APPHOST' -Filter "system.applicationHost/Sites/SiteDefaults/logFile/customFields" -Name "." -Value $setCustomFields
}

<#
    .SYNOPSIS
        Helper function used to test the LogCustomField state for a website.

    .PARAMETER LogCustomField
        A CimInstance collection of what state the LogCustomField should be.
#>

function Test-LogCustomField
{
    [CmdletBinding()]
    [OutputType([Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [Microsoft.Management.Infrastructure.CimInstance[]]
        $LogCustomFields
    )

    $inDesiredState = $true

    foreach ($customField in $LogCustomFields)
    {
        $filterString = "/system.Applicationhost/Sites/SiteDefaults/logFile/customFields/add[@logFieldName='{0}']" -f $customField.LogFieldName
        $presentCustomField = Get-WebConfigurationProperty -Filter $filterString -Name "."

        $shouldBePresent = $customField.Ensure -ne 'Absent'

        if ($presentCustomField)
        {
            $sourceNameMatch = $customField.SourceName -eq $presentCustomField.sourceName
            $sourceTypeMatch = $customField.SourceType -eq $presentCustomField.sourceType
            $doesNotMatchEnsure = (-not ($sourceNameMatch -and $sourceTypeMatch)) -eq $shouldBePresent
            if ($doesNotMatchEnsure)
            {
                $inDesiredState = $false
            }
        }
        else
        {
            if ($shouldBePresent)
            {
                $inDesiredState = $false
            }
        }
    }

    return $inDesiredState
}

#endregion

Export-ModuleMember -function *-TargetResource