Powershell Logging within modules and dot sourced scripts - powershell

Question

I have a few functions stored in a .psm1 file that is used by several different ps1 scripts. I created a logging function (shown below), which I use throughout these ps1 scripts. Typically, I import the module within a script by simply calling something like:
Import-Module $PSScriptRoot\Module_Name.psm1
Then within the module, I have a write logger function:
Write-Logger -Message "Insert log message here." #logParams
This function is used throughout the main script and the module itself. The splatting parameter #logParams is defined in my main .ps1 file and is not explicitly passed to the module, I suppose the variables are implicitly within the module's scope upon being imported. What I have works, but I feel like it isn't a great practice. Would it be better practice to add a param block within my module to require #logParams to be explicitly passed from the main .ps1 script? Thanks!
function Write-Logger() {
[cmdletbinding()]
Param (
[Parameter(Mandatory=$true)]
[string]$Path,
[Parameter(Mandatory=$true)]
[string]$Message,
[Parameter(Mandatory=$false)]
[string]$FileName = "Scheduled_IDX_Backup_Transcript",
[switch]$Warning,
[switch]$Error
)
# Creates new log directory if it does not exist
if (-Not (Test-Path ($path))) {
New-Item ($path) -type directory | Out-Null
}
if ($error) {
$label = "Error"
}
elseif ($warning) {
$label = "Warning"
}
else {
$label = "Normal"
}
# Mutex allows for writing to single log file from multiple runspaces
$mutex = new-object System.Threading.Mutex $false,'MutexTest'
[void]$mutex.WaitOne()
Write-Host "$(Format-LogTimeStamp) $label`: $message"
"$(Format-LogTimeStamp) $label`: $message" | Out-file "$path\$fileName.log" -encoding UTF8 -append
[void]$mutex.ReleaseMutex()
}

Answer 1

I have this code in ps1 that I dot source into scripts where I want to produce my own logs. The ps1 contains the simpleLogger class as well as the routine below that creates a global variable. The script can be dot sourced again and the global variable value passed to subsequently spawned jobs to maintain a single log file.
class simpleLogger
{
[string]$source
[string]$target
[string]$action
[datetime]$datetime
hidden [string]$logFile = $global:simpleLog
simpleLogger()
{
$this.datetime = Get-Date
}
simpleLogger( [string]$source, [string]$target, [string]$action )
{
$this.action = $action
$this.source = $source
$this.target = $target
$this.datetime = Get-Date
}
static [simpleLogger] log( [string]$source, [string]$target, [string]$action )
{
$newLogger = [simpleLogger]::new( [string]$source, [string]$target, [string]$action )
do {
$done = $true
try {
$newLogger | export-csv -Path $global:simpleLog -Append -NoTypeInformation
}
catch {
$done = $false
start-sleep -milliseconds $(get-random -min 1000 -max 10000)
}
} until ( $done )
return $newLogger
}
}
if( -not $LogSession ){
$global:logUser = $env:USERNAME
$global:logDir = $env:TEMP + "\"
$startLog = (get-date).tostring("MMddyyyyHHmmss")
$global:LogSessionGuid = (New-Guid)
$global:simpleLog = $script:logDir+$script:logUser+"-"+$LogSessionGuid+".log"
[simpleLogger]::new() | export-csv -Path $script:simpleLog -NoTypeInformation
$global:LogSession = [simpleLogger]::log( $script:logUser, $LogSessionGuid, 'Log init' )
}