Enhance prompt function to show username/hostname in SSH connection

[rkeithhill]

As I've been using Windows 10 OpenSSH's sshd service and connecting to my Windows 10 system using ssh, I've been missing seeing the [username@hostname] info the PowerShell prompt on the remote system that I'm used to seeing when I ssh into a Linux box.

We could rectify that by adding the following to our prompt function (somewhere before the prompt suffix):

"$(if (Test-Path Env:\SSH_CONNECTION) {" [$([System.Environment]::UserName)@$([System.Environment]::MachineName)]"})"

A few notes, you get the remote system's PowerShell prompt when you A) ssh into the remote system with OpenSSH sshd running and configured with this subsystem:

Subsystem	powershell	C:/Program Files/PowerShell/6-preview/pwsh.exe -sshs -NoLogo -NoProfile

And no, I'm not quite sure why we get the posh-git prompt when the above specifies -NoProfile. Anyway, I've modified my posh-git prompt to this:

$global:GitPromptSettings.DefaultPromptBeforeSuffix.Text = '`n$([DateTime]::Now.ToString("MM-dd HH:mm:ss"))$(if (Test-Path Env:\SSH_CONNECTION) {" [$([System.Environment]::UserName)@$([System.Environment]::MachineName)]"})'

So that when I ssh into this system, I see this prompt:

C:\Users\hillr
06-27 09:51:19 [hillr@HILLR2] 1>

Note that when you use PS Remoting over SSH, PowerShell controls the prompt. In that case, you currently get just the hostname in the prompt:

06-27 09:51:57 8> Enter-PSSession -HostName hillr2
hillr@KEYSIGHT@hillr2's password:
[hillr2]: PS C:\Users\hillr\Documents>

But that is changing - see PowerShell/PowerShell#7156 & PowerShell/PowerShell#7191

So, should we consider covering this scenario with our prompt function or just add an example of how to customize the posh-git prompt if you want this feature?

[dahlbyk]

How is prompt handled for other PowerShell remoting situations?

[rkeithhill]

If I use WinRM as a transport instead of SSH, I get:

06-27 11:39:07 9> Enter-PSSession -ComputerName hillr2
[hillr2]: PS C:\Users\hillr\Documents>

That's pretty much the only other remoting scenario I can think off. Note: it is subtle but the parameter -ComputerName on Enter-PSSession causes the command to use WinRM while the -HostName parameter causes the command to use SSH.

[dahlbyk]

If the default behavior is to put the remote host before PS $pwd>, I'm inclined to follow suit with remote host information in DefaultPromptPrefix value. Is there a downside to using environment variables, compared with the implementation over in PowerShell/PowerShell#7191?

[rkeithhill]

OK, back from vacation … that's a great thought but when you are ssh'd into a remote system where PowerShell has been configured as the default shell, the Runspace.ConnectionInfo property is $null. That's because as far as PowerShell is concerned, it isn't involved in remoting. This is still useful info though in the (non-remoting) ssh scenario.