PrometheusExporter.psm1
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# List of valid metric types enum MetricType { counter gauge histogram summary } # Metric descriptor class class MetricDesc { [String] $Name [String] $Help [MetricType] $Type [string[]] $Labels MetricDesc([String] $Name, [MetricType] $Type, [String] $Help, [string[]] $Labels) { if (-Not $this.isValidName($Name)) { throw "Not a valid metric name: $Name" } foreach ($Label in $Labels){ if (-Not $this.isValidName($Label)) { throw "Not a valid label name: $Label" } } $this.Name = $Name $this.Type = $Type $this.Help = $Help -replace "[\r\n]+", " " # Strip out new lines $this.Labels = $Labels } hidden [bool] isValidName([string] $Name){ # Notice the : is removed from the regex as those should not be used by exporters # according to the documentation return $Name -match "^[a-zA-Z_][a-zA-Z0-9_]*$" } } class Metric { [MetricDesc] $Descriptor [float] $Value [string[]] $Labels Metric([MetricDesc] $Descriptor, [Float] $Value, [string[]] $Labels) { $this.Descriptor = $Descriptor $this.Value = $Value $this.Labels = $Labels } [String] ToString() { $FinalLabels = [System.Collections.Generic.List[String]]::new() if ($this.Descriptor.Labels.Count -gt 0) { if($this.Descriptor.Labels.Count -ne $this.Labels.Count) { throw "Less metric labels specified than there are labels in the descriptor" } for ($i=0; $i -lt $this.Descriptor.Labels.Count; $i++) { $l = $this.Descriptor.Labels[$i] $v = $this.Labels[$i] $v = $v.Replace("\","\\").Replace("""", "\""").Replace("`n", "\n") $FinalLabels.Add("$l=`"$v`"") } $StringLabels = $FinalLabels -join "," $StringLabels = "{$StringLabels}" } else { $StringLabels = "" } return $this.Descriptor.Name + $StringLabels + " " + $this.Value } } class Channel { $Metrics = [System.Collections.Generic.List[Metric]]::new() AddMetrics([Metric[]] $Metrics) { $this.Metrics.AddRange($Metrics) } [String] ToString() { $Lines = [System.Collections.Generic.List[String]]::new() $LastDescriptor = $null foreach($m in $this.Metrics){ if($m.Descriptor -ne $LastDescriptor){ $LastDescriptor = $m.Descriptor $name = $LastDescriptor.Name $help = $LastDescriptor.Help $type = $LastDescriptor.Type $Lines.Add("# HELP $name $help") $Lines.Add("# TYPE $name $type") } $Lines.Add([String]$m) } return $Lines -join "`n" } } class Exporter { $Collectors = [System.Collections.Generic.List[ScriptBlock]]::new() [UInt32] $Port Exporter ([UInt32] $Port) { $this.Port = $Port } Register ([ScriptBlock] $Collector) { $this.Collectors.Add($Collector) } [String] Collect () { $ch = [Channel]::new() foreach ($c in $this.Collectors) { $ch.AddMetrics($c.Invoke()) } return [String]$ch } Start () { [Console]::TreatControlCAsInput = $True $Http = [System.Net.HttpListener]::new() $Prefix = 'http://+:{0}/' -f $this.Port $Http.Prefixes.Add($Prefix) $Http.Start() $Error.Clear() New-LogMessage -Msg ("Exporter started listening on $Prefix") try { while ($Http.IsListening) { $ContextAsync = $http.GetContextAsync() while (-not $ContextAsync.AsyncWaitHandle.WaitOne(200)) { if ([console]::KeyAvailable) { $key = [system.console]::readkey($true) if (($key.modifiers -band [consolemodifiers]"control") -and ($key.key -eq "C")) { Write-Warning "Quitting, user pressed control C..." Return } } } $Context = $ContextAsync.GetAwaiter().GetResult() $Request = $Context.Request $Response = $Context.Response $Response.StatusCode = 200 if ($Request.HttpMethod -eq "GET" -and $Request.Url.LocalPath -in ("/", "/metrics")) { Try { $PromResponse = $this.Collect() $Response.AddHeader("Content-Type", "text/plain; version=0.0.4; charset=utf-8") } catch { write-host $_ $Response.StatusCode = 500 $PromResponse = 'Internal Server Error' } } else { $Response.StatusCode = 404 $PromResponse = 'Page not found' } # return results $Buffer = [Text.Encoding]::UTF8.GetBytes($PromResponse) $Response.ContentLength64 = $Buffer.Length $Response.OutputStream.Write($Buffer, 0, $Buffer.Length) $Response.Close() $StatusCode = $Response.StatusCode $Method = $Request.HttpMethod $Path = $Request.Url.LocalPath if ($null -eq $Request.RemoteEndPoint){ $RemoteAddr = "-" } else { $RemoteAddr = $Request.RemoteEndPoint.ToString() } New-LogMessage -Msg "$RemoteAddr ""$Method $Path"" $StatusCode" } } finally { New-LogMessage -Msg "Stopping exporter." $Http.Stop() $Http.Close() } } } function New-LogMessage([String] $Msg){ Write-Host "$(Get-Date -Format o) $Msg" } function New-MetricDescriptor( [Parameter(Mandatory=$true)][String] $Name, [Parameter(Mandatory=$true)][MetricType] $Type, [Parameter(Mandatory=$true)][String] $Help, [string[]] $Labels ) { return [MetricDesc]::new($Name, $Type, $Help, $Labels) } function New-PrometheusExporter( [Parameter(Mandatory=$true)][uint32] $Port ){ return [Exporter]::new($Port) } function Register-Collector ( [Parameter(Mandatory=$true)][Exporter] $Exporter, [Parameter(Mandatory=$true)][ScriptBlock] $Collector ) { $exporter.Register($Collector) } function New-Metric ( [Parameter(Mandatory=$true)][MetricDesc] $MetricDesc, [Parameter(Mandatory=$true)][float] $Value, [string[]] $Labels ) { return [Metric]::new($MetricDesc, $Value, $Labels) } Export-ModuleMember -Function New-MetricDescriptor, New-PrometheusExporter, New-Metric, Register-Collector |