Configure Git client to use corporate proxy and authenticate as current user

set-GitUserProxySettings.ps1

# This takes a guess at what Git config should be for proxy. Effectivly we're doing netstat.exe | find "8080"

# Lookup current user via Active Directory
[reflection.assembly]::LoadWithPartialName("System.DirectoryServices.AccountManagement") | out-null
$currentUser=[System.DirectoryServices.AccountManagement.UserPrincipal]::Current

#region Test if behind a proxy. This also generates some traffic that we'll use to determine proxy URL
try {
    Write-output "Testing internet access"
    $status = (Invoke-WebRequest -Uri "https://www.powershellgallery.com/api/v2" -UseBasicParsing).StatusDescription
    Write-Output "`tProxy test: $status"
}
catch {
    # web request failed
    $ex = $_.exception[0]
    # $fullError = $ex | Format-List -Force
    Write-Output "`tProxy test: $($ex.message)"
    Write-output "Enabling proxy authentication and session options"
    
    # Make PowerShell use proxy with current credentials
    $browser = New-Object System.Net.WebClient 
    $browser.Proxy.Credentials =[System.Net.CredentialCache]::DefaultNetworkCredentials
    
    # try again
    try{
        $status = (Invoke-WebRequest -Uri "https://www.powershellgallery.com/api/v2" -UseBasicParsing).StatusDescription
        Write-Output "`tProxy test: $status"
        }
    catch {
        $ex = $_.exception[0]
        $fullError = $ex | Format-List -Force
        write-output "internet access failed $($ex.message)"
        $fullError
        throw $ex.InnerException
    }
}
#endregion

# Have a guess at current session's autodiscovered internet proxy
$proxyPort='8080'
try{
    $arrayOfConnectionsToProxyPort=@(Get-NetTCPConnection | where-object {($_.RemotePort -eq $proxyPort)})
    $probablyProxyIP=($arrayOfConnectionsToProxyPort | Group-Object -Property RemoteAddress | sort-object -descending -property count)[0].name # most frequent

    #Perform a DNS Reverse Lookup (IP to hostname .Net):
    $proxyFullyQualifiedDomainName=[System.Net.Dns]::GetHostEntry($probablyProxyIP).HostName

    & git.exe config --global http.proxy "http://$($currentUser.SamAccountName)@$($proxyFullyQualifiedDomainName):$($proxyPort)"

    }
catch{
    Write-Output "Didn't find any connections to $proxyPort that look like proxy"
}

# open git config to review whats been configured
# & git.exe config --global --edit