Re: [Patch 1/3] connect.c: add nonstopssh variant to the sshVariant set.

From: Elijah Newren <newren@gmail.com>
Date: Apr 30, 2021, 17:17 UTC
Message-ID: <CABPp-BE_5c1vXuxPWTO82cGmyajXxpxW+-ycZ+-5vy+tsV3bUA@mail.gmail.com>
In-Reply-To: <012601d73ddf$3d0cf660$b726e320$@nexbridge.com>

On Fri, Apr 30, 2021 at 9:38 AM Randall S. Becker <rsbecker@nexbridge.com> wrote:

Show 23 quoted lines

>
> On April 30, 2021 12:25 PM, Elijah Newren wrote:
> >On Fri, Apr 30, 2021 at 7:58 AM Randall S. Becker <rsbecker@nexbridge.com>
> >wrote:
> >>
> >> From ba4beb8ed0dff67ae6b95692d346adce346e2871 Mon Sep 17 00:00:00
> >2001
> >> From: "Randall S. Becker" <rsbecker@nexbridge.com>
> >> Date: Fri, 30 Apr 2021 09:56:09 -0400
> >> Subject: [Patch 1/3] connect.c: add nonstopssh variant to the sshVariant set.
> >>
> >> This enhancement allows the NonStop SSH subsystem to be supported by
> >> git without the need of a wrapper script. The command arguments for
> >> the platform SSH client in /G/system/zssh/sshoss are constructed based
> >> on optional supplied environment variables SSH2_PROCESS_NAME (system
> >> defined), SSH_SUPPRESS_QUIET, and SSH_SUPPRESS_BANNER.
> >
> >Before introducing 3 new special environment variables, I think this commit
> >message should explain why you can't just use
> >
> >GIT_SSH_COMMAND="/G/system/zssh/sshoss -Z -Q -S"
>
> No, it would be GIT_SSH_COMMAND='/G/system/zssh/sshoss -Z -Q -S $ZSSH0' and that does not work correctly in the current git code base.

Is the problem that $ZSSH0 may contain spaces, or that $ZSSH0 is expected to change over time and you don't want to have to re-run

GIT_SSH_COMMAND="/G/system/zssh/sshoss -Z -Q -S $ZSSH0"

each time?

Show 8 quoted lines

> >particularly since GIT_SSH_COMMAND was introduced specifically so people
> >wouldn't have to create wrapper scripts to pass to GIT_SSH.
>
> Going back through the archive to why this is needed: https://public-inbox.org/git/008101d4f3db$56c20410$04460c30$@nexbridge.com/
>
> The SSH2_PROCESS_NAME is a system environment variable, not something I am introducing, that specifies the name of the SSH process. It's format is [\NODE.]$NAME, which causes shell to blank it out. A wrapper script is currently mandatory on this platform.
>
> I have been looking for a solution since that thread.

Ah, so it's the case that $ZSSH0 changes for you, but is set somewhere by the system and you don't want to have to redefine GIT_SSH_COMMAND each time you log into some box.

At a minimum, this explanation should be included in the commit message here, otherwise the problem you're trying to address won't be understood by reviewers. It wasn't at all clear to me from your cover letter or this commit, and I even had trouble parsing it out of the other thread you linked to. Only this above paragraph about SSH2_PROCESS_NAME and its value on your system explain it. (It's still hard to tell what from your "[\NODE.]$NAME" is literal text and what is meant to be replaced, though, it might be useful to have an example of the literal value of SSH2_PROCESS_NAME on some random node in the explanation as well.)