This PowerShell Exporter lets you export Prometheus Gauge Metrics from the result of a PowerShell cmdlet.

WARNING this is still a PoC; things will change for sure

Usage

The cmdlets are defined inside metrics.psm1 and are loaded at the application startup, e.g.:

# count the number tcp connections grouped by their remote address, port, and state.
# NB this must return PowerShellExporter.Metric objects.
function Get-TcpConnectionsMetrics {
    Get-NetTCPConnection `
        | Where-Object {$_.RemotePort -ne 0} `
        | Where-Object {$_.LocalAddress -ne '127.0.0.1' -and $_.LocalAddress -ne '::1'} `
        | Group-Object -Property 'RemoteAddress','RemotePort','State' `
        | ForEach-Object {
            [PowerShellExporter.Metric]::new(
                # metric value
                $_.Count,
                # metric labels
                @{
                    'remote_address' = $_.Group[0].RemoteAddress
                    'remote_port' = $_.Group[0].RemotePort
                    'state' = $_.Group[0].State
                })
        }
}

The metrics are defined inside metrics.yml and are evaluated at every prometheus scrape, e.g.:

metrics:
  # sample promql:
  #   sum(pse_tcp_connections) by (state)
  #   sum(pse_tcp_connections) by (remote_address)
  - name: pse_tcp_connections
    cmdlet: Get-TcpConnectionsMetrics

Prometheus can be configured with something alike:

global:
  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).
...
scrape_configs:
  ...
  - job_name: pse
    static_configs:
      - targets:
        - localhost:9360

This exporter can be installed as a Windows service with something alike:

.\PowerShellExporter help         # show help.
.\PowerShellExporter install      # install with default settings.
Start-Service PowerShellExporter  # start the service.

NB you can modify the default listening url http://localhost:9360/metrics with the -url command line argument, e.g., -url http://localhost:9360/pse/metrics.

NB you need to make sure this exporter metrics are not taking too long to complete by observing the scrape durations with the promql scrape_duration_seconds{job="pse"}.

Build

Type make and use what ends-up in the dist sub-directory.

If the PowerShell System.Management.Automation.dll assembly is not found, you need to get its location with the [PSObject].Assembly.Location snippet and modify the PowerShellExporter.csproj <HintPath>.