Post commit hook to run a Jenkins build

postcommit.ps1

# Powershell post-commit hook. Can be used with Tortoise SVN as a 
# client side hook using:
#  powershell.exe C:\path\to\postcommit.ps1 <JenkinsJob> <AuthToken> <JenkinsUser> <APIToken>
#
# You may need to bypass the Execution Policy (default is Restricted):
#
#  powershell.exe -ExecutionPolicy Bypass C:\path\to\postcommit.ps1 ...
#
# JenkinsJob is the job name
# AuthToken is set in job Build Triggers

param(
  [string] $job,
  [string] $jobToken,
  [string] $username,
  [string] $apiToken,
  [string] $cause = "post commit ($($env:UserName))",
  [string] $jenkinsHost = 'jenkins:8080'
)

# --- start helper functions ---

function Basic-Auth {
  param([string] $username, [string] $apiToken)
  'Basic ' + [Convert]::ToBase64String(
    [Text.Encoding]::ASCII.GetBytes("$($username):$($apiToken)")
  )
}

function Build-AuthHeader {
  param([string] $username, [string] $apiToken)
  @{Authorization = Basic-Auth $username $apiToken}
}

function Get-BuildUrl {
  "{0}/job/{1}/build?token={2}&cause={3}" -f $args;
}

function Get-CsrfHeader {
  param([string] $baseUri, [hashtable] $headers)

  $params = @{
    uri = "$($baseUri)/crumbIssuer/api/xml"
    method = 'GET'
    Headers = $headers
  }

  [xml] $crumb = Invoke-RestMethod @params -ErrorAction Stop
  @{
    name = $crumb.defaultCrumbIssuer.crumbRequestField
    value = $crumb.defaultCrumbIssuer.crumb
  }
}

function Trigger-Build {
  param([string] $url, [hashtable] $headers)

  $params = @{
    uri = $url
    method = 'POST'
    Headers = $headers
  }

  Invoke-RestMethod @params -ErrorAction Stop
}

# --- end helper functions ---

Try {
  $baseUri = "http://$($jenkinsHost)"
  $headers = Build-AuthHeader $username $apiToken
  $csrf = Get-CsrfHeader $baseUri $headers
  $headers.add($csrf.name, $csrf.value)
  $url = Get-BuildUrl $baseUri $job $jobToken $cause
  
  Trigger-Build $url $headers
} Catch {
  Write-Host $PSItem.ToString().Trim() -ForegroundColor Yellow
}