From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCH 0/3] Enable namespaced file capabilities Date: Fri, 23 Jun 2017 13:30:31 -0500 Message-ID: <20170623183031.GA20978@mail.hallyn.com> References: <1498157989-11814-1-git-send-email-stefanb@linux.vnet.ibm.com> <20170623160026.GA18257@mail.hallyn.com> <20170623163030.GA18820@mail.hallyn.com> <1498237641.3641.15.camel@HansenPartnership.com> <20170623172016.GA19551@mail.hallyn.com> <553a72c4-eda9-52d6-2ae2-f8687c0c7c70@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <553a72c4-eda9-52d6-2ae2-f8687c0c7c70-l3A5Bk7waGM@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Aleksa Sarai Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: containers.vger.kernel.org Quoting Aleksa Sarai (asarai-l3A5Bk7waGM@public.gmane.org): > >>So my essential point is that building the real kuid into the permanent > >>record of the xattr damages image portability, which is touted as one > >>of the real advantages of container images. > > > >'container images' aren't portable in that sense now - for at least > >many cases - because you have to shift the uid. However you're doing > >that, you may be able to shift the xattr the same way. > > Piling more things on top of that issue isn't going to make the > issue easier to solve IMO. Would shiftfs or shift-bindmounts also > have to do translation of arbitrary xattrs? Plus I would think that > handling xattrs would be harder than {u,g}ids because the image > unpacker now has to be aware of all xattrs that require remapping > (Which might be an ever-growing list). No, that's actually the point of Stefan's patch (versus mine). It should be able to generically map anything that is 'security.foo@uid=100' or 'trusted.foo@uid=100'. It doesn't need more intelligence than that. -serge