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From: "" <>
To: Trond Myklebust <>
Cc: "" <>,
	"" <>
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
Message-ID: <> (raw)
In-Reply-To: <>

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.


  reply index

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 bfields
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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