public inbox for containers@lists.linux.dev
 help / color / mirror / Atom feed
From: "Serge E. Hallyn" <serge@hallyn.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Linux Containers <containers@lists.linux-foundation.org>,
	Christian Brauner <christian.brauner@ubuntu.com>
Subject: Re: Use cases for multiple uid mapping?
Date: Tue, 1 Sep 2020 01:06:31 -0500	[thread overview]
Message-ID: <20200901060631.GA5193@mail.hallyn.com> (raw)
In-Reply-To: <87zh6eiyv7.fsf@x220.int.ebiederm.org>

On Fri, Aug 28, 2020 at 10:17:16AM -0500, Eric W. Biederman wrote:
> 
> We had a discussion in the hackroom at LPC talking about use cases for
> a shiftfs style setup where there are different mappings of uids to
> disk.
> 
> In the discussion we had a couple of ideas of kernel developments
> we should look at that address some of these.
> 
> - Fix rlimits in user namespaces (This potentially allows multiple
>   containers to run with the same userids simplifying the mapping
>   problem).
> 
> - Look at extending kuid_t to 64bits and using the highbits to
>   implement uids that are private to user namespaces and don't
>   map out.
>   
> - Look at ways for allowing setgroups unprivileged.
> 
> 
> Together this has the potential that the existing uid & gid mappings
> will be able to function the same as the proposed fusid mappings. Fingers crossed.
> 
> 
> I had some problems with audio and a lot of people were talking
> quickly.  So I did not manage to capture everyone's use cases.   And I
> definitely was not able to see how everyone's use cases interacted with
> the changes we are looking at.
> 
> I know for certain I missed Serge's usecase (apologies).
> 
> Can people follow up to this and report their use cases?

Sorry - I'll do so later this week.

> There are some real challenges and I would like to see if we
> can solve them, while avoiding scary problems like changing
> uids on write.
> 
> Eric
> 
> 
> 
> 
> 
> 
> 
>   
> 
_______________________________________________
Containers mailing list
Containers@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/containers

  parent reply	other threads:[~2020-09-01  6:07 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-28 15:17 Use cases for multiple uid mapping? Eric W. Biederman
2020-08-28 15:55 ` Stéphane Graber via Containers
2020-08-28 17:03   ` Sargun Dhillon
2020-08-30  5:48 ` James Bottomley
2020-09-01  6:06 ` Serge E. Hallyn [this message]
2020-09-01 14:53   ` Eric W. Biederman
2020-09-24 17:09     ` Alban Crequy
2020-09-25  8:13       ` Christian Brauner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200901060631.GA5193@mail.hallyn.com \
    --to=serge@hallyn.com \
    --cc=christian.brauner@ubuntu.com \
    --cc=containers@lists.linux-foundation.org \
    --cc=ebiederm@xmission.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox