Creating A Custom Prometheus Exporter With Powershell

# Note: To end the loop you have to kill the powershell terminal. ctrl-c wont work
param (
    $listen_port  = '8080',
    $metrics_file = 'metrics.txt'
)

# Create Http Server Object, listen on port 8080 and start
$http = [System.Net.HttpListener]::new()
$http.Prefixes.Add("http://localhost:$($listen_port)/")
$http.Start()

# INFINTE LOOP - Used to listen for requests
while ($http.IsListening) {
    # When a request is made in a web browser the GetContext() method will return a request object
    $context = $http.GetContext()
    # Listen on a patch called /metrics
    if ($context.Request.HttpMethod -eq 'GET' -and $context.Request.RawUrl -eq '/metrics') {
        # the html/data you want to send to the browser
        [string]$html = Get-Content $metrics_file -Raw
        #resposed to the request
        $buffer = [System.Text.Encoding]::UTF8.GetBytes($html) # convert htmtl to bytes
        $context.Response.ContentLength64 = $buffer.Length
        $context.Response.OutputStream.Write($buffer, 0, $buffer.Length) #stream to broswer
        $context.Response.OutputStream.Close() # close the response
    }
}