Automount coolness

Auto mounting of network shares in Linux is very useful. Just mount it into the directory structure and the applications don’t see the difference between local data and network data.

I currently have a setup where I access samba/cifs shares and, more recently, files over ssh using sshfs.

 

Basic setup

Automount is part of the autofs package

apt-get install autofs

The main configuration files are is /etc/auto.master

$ cat /etc/auto.master | grep -v ^#
+dir:/etc/auto.master.d
+auto.master

This is actually the default auto.master. The “+dir” line says to include *.autofs from /etc/auto.master.d. The last line probably means end-of-file – the docs are not clear on this point.

 

sshfs mounts

I got inspiration from here. Start by installing sshfs

apt-get install sshfs

Make sure you can ssh to the machine you want to use – that is the first step to making it work.

Create the config file for sshfs

$ cat /etc/auto.master.d/auto.sshfs | grep -v ^#
* -fstype=fuse,uid=${UID},gid=${GID},nodev,nonempty,noatime,allow_other,max_read=65536,IdentityFile=${HOME}/.ssh/id_rsa :sshfs\#${USER}@&\:

and add a line in a /etc/auto.master.d/*.autofs to let it included in the maps.

# cat /etc/auto.master.d/server.autofs | grep sshfs
/mnt/net/ssh /etc/auto.master.d/auto.sshfs

This means that accessing /mnt/net/ssh/myserver will give you access to the files on myserver using ssh.

Note that the key used is the .ssh/id_rsa from the mounting users home directory, and also that any configuration in .ssh/config is ignored. The root user must have the servers in the known_hosts files, otherwise there will be a silent yes/no question related to the fingerprint of the server.

 

Samba shares

This is an old configuration, so I’m vague on the packages needed, but I think it is cifs-utils.

Create the config file for samba

$ cat /etc/auto.master.d/auto.smb | grep -v ^#
* -fstype=cifs,credentials=${HOME}/.cifs/default,uid=${UID},gid=${GID} ://${SERVER}/&6,IdentityFile=${HOME}/.ssh/id_rsa :sshfs\#${USER}@&\:

and add a line in a /etc/auto.master.d/*.autofs for each server (this is different than the ssh version).

$ cat /etc/auto.master.d/server.autofs | grep smb
/mnt/net/serverA /etc/auto.master.d/auto.smb -DSERVER=serverA
/mnt/net/serverB /etc/auto.master.d/auto.smb -DSERVER=serverB
/mnt/net/serverC /etc/auto.master.d/auto.smb -DSERVER=serverC

In this example, three samba servers are available at /mnt/net/serverX, so in order to access the “home” share, go to /mnt/net/serverX/home. I usually make symlinks in my home folder to e.g. ~/net/serverX_home.

 

Debugging

As root

/etc/init.d/autofs stop
automount -f -d

And you get lots of information for your debugging. I found this ubuntu community post, that says something about autofs also.