Git remote return custom error messages

Hampton Moore· Sep 27, 2020, 22:26 UTC · lore

Hello, I have a custom ssh server that is handling validating users permissions, is there a way for me to return custom text back to the git client that's running push and pull? When I just send an error like "NOT A DOMAIN" through STOUT the git client displays "fatal: protocol error: bad line length character: NOT". I looked and could not find any obvious documentation on how I could do this, or if it would even be possible. Does anyone have any ideas?

Thank you, Hampton Moore

brian m. carlson· Sep 27, 2020, 23:28 UTC · re: Hampton Moore · lore

Re: Git remote return custom error messages

On 2020-09-27 at 22:26:56, Hampton Moore wrote:

Show 8 quoted lines

> Hello,
> I have a custom ssh server that is handling validating users
> permissions, is there a way for me to return custom text back to the
> git client that's running push and pull? When I just send an error
> like "NOT A DOMAIN" through STOUT the git client displays "fatal:
> protocol error: bad line length character: NOT". I looked and could
> not find any obvious documentation on how I could do this, or if it
> would even be possible. Does anyone have any ideas?

You haven't specified at what stage you're thinking about sending this result, so it's not 100% clear what the right answer is, but depending on the stage, you could try two things.

First, you can try sending an error packet:

  error-line     =  PKT-LINE("ERR" SP explanation-text)

That would usually be displayed to the user and it will be fatal. If you're in the middle of the protocol, and this is non-fatal, you can try using standard error, since that's usually hooked up to the terminal via the sideband. It's possible some very old Git versions won't support that, though.

-- 
brian m. carlson: Houston, Texas, US