From: "bfields@fieldses.org" <bfields@fieldses.org>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"Anna.Schumaker@netapp.com" <Anna.Schumaker@netapp.com>
Subject: Re: [PATCH 6/9] NFSv4: Convert the NFS client idmapper to use the container user namespace
Date: Thu, 25 Apr 2019 11:33:39 -0400 [thread overview]
Message-ID: <20190425153339.GB8133@fieldses.org> (raw)
In-Reply-To: <e94c2488d89ae13675f9931d013a3d711459ecad.camel@hammerspace.com>
On Thu, Apr 25, 2019 at 03:00:22PM +0000, Trond Myklebust wrote:
> The assumption is that if you have enough privileges to mount a
> filesystem using the NFS client, then you would also have enough
> privileges to run a userspace client, so there is little point in
> restricting the NFS client.
>
> So the guiding principle is that a NFS client mount that is started in
> a container should behave as if it were started by a process in a "real
> VM". That means that the root uid/gid in the container maps to a root
> uid/gid on the wire.
> Ditto, if there is a need to run the idmapper in the container, then
> the expectation is that processes running as 'user' with uid 'u', will
> see their creds mapped correctly by the idmapper. Again, that's what
> you would see if the process were running in a VM instead of a
> container.
>
> Does that all make sense?
Yes, thanks!
I thought there was a problem that the idmapper depended on
keyring usermodehelper calls that it was hard to pass namespace
information to. Did that get fixed and I missed it or or forgot?
>
> So this means that any orchestrator software which may be setting up
> NFS mounts as part of setting up the container has 2 options:
>
> 1. Either perform the mount outside the container namespaces, in which
> case the container process uids/gids are mapped from their
> user_namespace into the user_namespace of the orchestrator, and the
> uids/gids on the wire will reflect those mapped uids/gids (so uid 0
> in the container will be mapped to uid xxx where xxx is decided by
> the orchestrator).
> 2. Perform the mount inside the container namespaces, in which case the
> container process uids/gids go on the wire as-is.
OK, great, that sounds perfect.
--b.
next prev parent reply other threads:[~2019-04-25 15:34 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 21:46 [PATCH 0/9] Client container fixes Trond Myklebust
2019-04-24 21:46 ` [PATCH 1/9] SUNRPC: Cache cred of process creating the rpc_client Trond Myklebust
2019-04-24 21:46 ` [PATCH 2/9] NFS: Store the credential of the mount process in the nfs_server Trond Myklebust
2019-04-24 21:46 ` [PATCH 3/9] SUNRPC: Use the client user namespace when encoding creds Trond Myklebust
2019-04-24 21:46 ` [PATCH 4/9] SUNRPC: Use namespace of listening daemon in the client AUTH_GSS upcall Trond Myklebust
2019-04-24 21:46 ` [PATCH 5/9] NFS: Convert NFSv3 to use the container user namespace Trond Myklebust
2019-04-24 21:46 ` [PATCH 6/9] NFSv4: Convert the NFS client idmapper " Trond Myklebust
2019-04-24 21:46 ` [PATCH 7/9] NFS: Convert NFSv2 " Trond Myklebust
2019-04-24 21:46 ` [PATCH 8/9] NFS: When mounting, don't share filesystems between different user namespaces Trond Myklebust
2019-04-24 21:46 ` [PATCH 9/9] lockd: Store the lockd client credential in struct nlm_host Trond Myklebust
2019-04-25 14:32 ` [PATCH 6/9] NFSv4: Convert the NFS client idmapper to use the container user namespace J. Bruce Fields
2019-04-25 15:00 ` Trond Myklebust
2019-04-25 15:33 ` bfields [this message]
2019-04-25 16:40 ` Trond Myklebust
2019-04-25 16:45 ` bfields
2019-04-25 16:48 ` Trond Myklebust
2019-04-25 20:16 ` bfields
2019-06-14 18:52 ` [PATCH 1/9] SUNRPC: Cache cred of process creating the rpc_client Ido Schimmel
2019-06-20 12:33 ` Ido Schimmel
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