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Re: [RFC/PATCH] connect: add GIT_SSH_{SEND,RECEIVE}{,_COMMAND} env variables

From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date
Jan 4, 2018, 10:10 UTC
Message-ID
<87a7xuc4ty.fsf@evledraar.gmail.com>
In-Reply-To
<20180104044230.GA12113@sigill.intra.peff.net>
On Thu, Jan 04 2018, Jeff King jotted:
Show 26 quoted lines
> On Thu, Jan 04, 2018 at 01:08:28AM +0100, Ævar Arnfjörð Bjarmason wrote:
>
>> Hopefully this is clearer, and depending on how the rest of the
>> discussion goes I'll submit v2 with something like this in the commit
>> message:
>>
>> SSH keys A and B are known to the remote service, and used to identify
>> two different users.
>>
>> A can only push to repository X, and B can only fetch from repository Y.
>>
>> Thus, if you have a script that does:
>>
>>     GIT_SSH_COMMAND="ssh -i A -i B" git ...
>>
>> It'll always fail for pulling from X, and pushing to Y. Supply:
>>
>>     GIT_SSH_COMMAND="ssh -i B -i A" git ...
>>
>> And now pulling will work, but pushing won't.
>
> I get that you may have two different keys to go with two different
> identities on a remote system. But I'm not sure I understand why
> "sending" or "receiving" is the right way to split those up. Wouldn't
> you also sometimes want to fetch from repository X? IOW, wouldn't you
> want to tie identity "A" to repository "X", and "B" to repository "Y?

That's badly explained, sorry, when I say "push" I mean "push and/or pull".

I don't know about Github, but on Gitlab when you provision a deploy key and associate it with a repo it must be *globally* rw or ro, there's no way to on a per-repo basis say it should be rw ro.

I have a job that's fetching a bunch of repos to review code in them (for auditing purposes). It then commits the results of that review to other git repos.

Thus I want to have a ro key to all those reviewed repos, but rw keys to the audit repo itself (and it'll also pull with the rw key).

Hence this patch, I thought *maybe* others would be interested in this since it seems to me to be an easy thing to run into with these ssh-key based hosting providers, but maybe not.

Show 6 quoted lines
>> So now I just have a GIT_SSH_COMMAND that dispatches to different keys
>> depending on the operation, as noted in the commit message, and I can
>> assure you that without that logic it doesn't work.
>
> You mentioned host aliases later, which is the solution I've seen in the
> wild. And then you can map each remote to a different host alias.
Previous: Jeff KingNext: Jeff King
Message 5 of 8 in “connect: add GIT_SSH_{SEND,RECEIVE}{,_COMMAND} env variables”
  1. connect: add GIT_SSH_{SEND,RECEIVE}{,_COMMAND} env variablesÆvar Arnfjörð Bjarmason, Jan 3, 2018
  2. Junio C HamanoJan 3, 2018
  3. Ævar Arnfjörð BjarmasonJan 4, 2018
  4. Jeff KingJan 4, 2018
  5. Ævar Arnfjörð BjarmasonJan 4, 2018
  6. Jeff KingJan 4, 2018
  7. Ævar Arnfjörð BjarmasonJan 4, 2018
  8. Junio C HamanoJan 4, 2018

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