fairly complex nested filesystems question

fairly complex nested filesystems question

[chris barry]

Greetings,

I'm trying to create a nested filesystem structure that combines an
automounted nfs home directory, with bind mounts from the local machine.

The structure will look like this:
/
|-home
   `-user1        <-(nfs somehost:/home/user1)
       |-myftp    <-(bind /var/ftp/users/user1)
       `-pub_ftp  <-(bind /var/ftp/pub)

The entire structure needs to get automounted as a group on login, and
then is chrooted as users ftp into this box.

My auto.master looks like this:
/home   /etc/auto.home --timeout=30

My auto.home looks like this:
*              -fstype=nfs,rw,intr   10.20.30.40:/home/& \
/home/&/myftp  -fstype=file          :/var/ftp/users/& \
/home/&/ftp    -fstype=file          :/var/ftp/pub


My home mounts fine via nfs, and is chrooted (when I ftp in), but the
other mounts do not occur, and no errors are thrown. Thinking it was a
timing issue, and the chroot had occurred before the local mounts
happened, I came in via ssh (which is not chrooted, but will not be
available to users later), and I get the same results. Finding any
examples of this kind of map has been challenging to say the least. 

I'm assuming my map syntax is incorrect, or is this type of thing simply
impossible?


Unfortunately, I have to stay at these versions.
RHEL4U5 2.6.9-55.ELsmp
ProFTPD  Version 1.3.1
Linux automount version 4.1.3-199.3


What am I doing wrong here?


Thanks,
-C

Re: fairly complex nested filesystems question

[Ian Kent]

On Thu, 2007-12-20 at 18:29 -0500, chris barry wrote:
> Greetings,
> 
> I'm trying to create a nested filesystem structure that combines an
> automounted nfs home directory, with bind mounts from the local machine.
> 
> The structure will look like this:
> /
> |-home
>    `-user1        <-(nfs somehost:/home/user1)
>        |-myftp    <-(bind /var/ftp/users/user1)
>        `-pub_ftp  <-(bind /var/ftp/pub)
> 
> The entire structure needs to get automounted as a group on login, and
> then is chrooted as users ftp into this box.
> 
> My auto.master looks like this:
> /home   /etc/auto.home --timeout=30
> 
> My auto.home looks like this:
> *              -fstype=nfs,rw,intr   10.20.30.40:/home/& \
> /home/&/myftp  -fstype=file          :/var/ftp/users/& \
> /home/&/ftp    -fstype=file          :/var/ftp/pub

This is not valid for a couple of reasons.
First the * will match every key and so nothing else will be seen.
The second and third entries aren't valid map entries for an indirect
map either. Even if they were then the & can't be used on the left hand
side of a map entry. This is because the & is replaced by the key that
has been matched and so can't be used within the key itself. The -fstype
should refer to a valid filesystem but I don't think file is a valid
filesystem. If you're intending this to indicate a bind mount then just
leave out the -fstype=file and leave the :<path>. 

Ian

Re: fairly complex nested filesystems question

[chris barry]

On Fri, 2007-12-21 at 23:37 +0900, Ian Kent wrote:
> On Fri, 2007-12-21 at 09:13 -0500, chris barry wrote:
> > On Fri, 2007-12-21 at 20:44 +0900, Ian Kent wrote:
> > > On Thu, 2007-12-20 at 18:29 -0500, chris barry wrote:
> > > > Greetings,
> > > > 
> > > > I'm trying to create a nested filesystem structure that combines an
> > > > automounted nfs home directory, with bind mounts from the local machine.
> > > > 
> > > > The structure will look like this:
> > > > /
> > > > |-home
> > > >    `-user1        <-(nfs somehost:/home/user1)
> > > >        |-myftp    <-(bind /var/ftp/users/user1)
> > > >        `-pub_ftp  <-(bind /var/ftp/pub)
> > > > 
> > > > The entire structure needs to get automounted as a group on login, and
> > > > then is chrooted as users ftp into this box.
> > > > 
> > > > My auto.master looks like this:
> > > > /home   /etc/auto.home --timeout=30
> > > > 
> > > > My auto.home looks like this:
> > > > *              -fstype=nfs,rw,intr   10.20.30.40:/home/& \
> > > > /home/&/myftp  -fstype=file          :/var/ftp/users/& \
> > > > /home/&/ftp    -fstype=file          :/var/ftp/pub
> > > 
> > > This is not valid for a couple of reasons.
> > > First the * will match every key and so nothing else will be seen.
> > > The second and third entries aren't valid map entries for an indirect
> > > map either. Even if they were then the & can't be used on the left hand
> > > side of a map entry. This is because the & is replaced by the key that
> > > has been matched and so can't be used within the key itself. The -fstype
> > > should refer to a valid filesystem but I don't think file is a valid
> > > filesystem. If you're intending this to indicate a bind mount then just
> > > leave out the -fstype=file and leave the :<path>. 
> > > 
> > > Ian
> > > 
> > 
> > Ian,
> > 
> > Thanks so much for your response. I got that one wrong totally wrong. 
> > 
> > Given the drawing and intent though, is the idea itself even possible,
> > or is it simply not workable in any way? If it /is/ possible, any idea
> > on how it should be done? From your explanation, I'm (taking a blind
> > stab here) thinking something like:
> > 
> > *    -fstype=nfs,rw,intr   10.20.30.40:/home/& \
> >      ./myftp                 :/var/ftp/users/& \
> >      ./ftp                   :/var/ftp/pub
> 
> Hehe, that's not quite right either.
> Sorry for the curt e-mail, I'm a bit loaded up at the moment.
> 
> We didn't get the autofs version you're using for this either.
> 
> That's interesting use of the wildcard key, I'm not sure whether that
> would work but, in theory, it just might.
> 
> So a map would need to be something like:
> 
> *	/	-fstype=nfs,rw,intr   10.20.30.40:/home/& \
> 	/myftp  	               :/var/ftp/users/& \
> 	/ftp    	               :/var/ftp/pub
> 
> The initial "/" (the root of the multi-mount) is allowed to be omitted
> as an accepted shortcut. The "." isn't legal the way it is specified
> above.
> 
> Strictly speaking the mount-point directories (such
> as /home/<someuser>/myftp and /home/<someuser>/ftp) must already exist
> as autofs doesn't, and often can't (and should'nt be able to) create
> directories on a remote server as it's operating as root.
> 
> Ian
> 
> 
(putting back on the list)

Thanks Ian! I'll give that a go.

Cheers,
-C