{{tag>howto autofs cifs filesystem howto linux mount mounting samba smb ubuntu debian}}
<WRAP center round important 60%>
**2022-11-30**: Please note that I have discovered, that this howto is more complicated than it needs to be and is not taking advantage of the flexibility offered by autofs. But... It will work for ONE user who needs shares from ONE server mounted into his/her/... home.

Anyway, this howto needs refactoring... stay tuned.
</WRAP>
====== automount CIFS share with autofs ======

This HowTo will prepare a Linux client to automatically mount CIFS shares from a remote Samba server on access/demand. Since I am mounting different filesystems, I have structured my mountpoints as follows:
<code>
/
├── home
│   ├── USER
│   │   ├── mnt
│   │   │   ├── cifs
│   │   │   │   ├── smb-server-a.fqdn
│   │   │   │   │   ├── share-a
│   │   │   │   │   ├── share-b
│   │   │   │   │   └── share-c
│   │   │   │   ├── smb-server-b.fqdn
│   │   │   │   │   ├── share-b
│   │   │   │   │   ├── share-b
│   │   │   │   │   └── share-c
│   │   │   ├── sshfs
│   │   │   │   ├── ssh-server-a.fqdn
</code>

From here on, I will use “mysambaserver.local” as the Samba servers FQDN, “mysambaserver” as its hostname, “myusername”  as my username, “mygroup” as group and “myPassWord” as the password.

At time of writing, the server is running Ubuntu 18.04.4 LTS and the client is running Ubuntu 20.04.1 LTS.

This HowTo got compiled by trial and error and from these sources:
  * https://wiki.ubuntuusers.de/Autofs/#Samba-Freigabe
  * https://www.elektronik-kompendium.de/sites/raspberry-pi/2102201.htm
  * https://wiki.ubuntuusers.de/Samba_Client_cifs/
  * https://wiki.ubuntuusers.de/Gigolo/
  * https://blog.marvin-menzerath.de/artikel/samba-freigaben-mit-autofs-automatisch-ein-aushaengen/
  * https://www.howtoforge.com/accessing_windows_or_samba_shares_using_autofs
  * https://wiki.samba.org/index.php/Mounting_samba_shares_from_a_unix_client
  * https://kalitut.com/samba-shares-fstab/

===== Install Required packages, check supported filesystems =====

Install the required packages on the client (gigolo is just “nice to have”) and check if its kernel supports CIFS.
<sxh bash; gutter: false>
apt -y install autofs cifs-utils smbclient gigolo gvfs-backends gvfs-fuse fuse
ls -1 /lib/modules/$(uname -r)/kernel/fs | grep "cifs"
</sxh>
  cifs
  
===== Check remote SAMBA connection =====
Check remote connection to the Samba server:
<sxh bash; gutter: false>
smbclient -N -L //<mysambaserver.local>/
</sxh>
        Sharename       Type      Comment
        ---------       ----      -------
        share-a         Disk      Share A
        share-b         Disk      Share B
        share-c         Disk      Share C
        IPC$            IPC       IPC Service (mysambaserver server (Samba, Ubuntu))
  SMB1 disabled -- no workgroup available
 

===== Check authenticated login =====

Check an authenticated remote login. If the command line asks for a password, enter the SMB password which is configured for the user at the Samba server (via smbpasswd).
<sxh bash; gutter: false>
smbclient -U <myusername> -L //<mysambaserver.local>/
</sxh>
  Enter WORKGROUP\myusername's password: [myPassWord] <--- enter the password
        Sharename       Type      Comment
        ---------       ----      -------
        share-a         Disk      Share A
        share-b         Disk      Share B
        share-c         Disk      Share C
        IPC$            IPC       IPC Service (mysambaserver server (Samba, Ubuntu))
  SMB1 disabled -- no workgroup available

===== Create mount point =====

Create the mount point in the users home directory:
<sxh bash; gutter: false>
mkdir -pv /home/<myusername>/mnt/cifs
chown -R <myusername>:<mygroup> /home/<myusername>/mnt/
</sxh>

===== autofs configuration =====
The configuration consists of the master map file (/etc/auto.master), the corresponding map file (/etc/auto.mysambaserver-cifs) and the key file which contains the credentials for authentication.
In the following we will configure autofs to mount shares to /home/<myusername>/mnt/cifs/<mysambaserver.local>/<share-name>.

===== Map file =====

Create the mapfile
<sxh bash; gutter: false>
vim /etc/auto.<mysambaserver>-cifs
</sxh>
<sxh bash; title: /etc/auto.mysambaserver-cifs>
#!/bin/bash
# $Id$
# This file must be executable to work! chmod 755!
set -x
KEY="${1}"
# Note: create a cred file for each windows/Samba-Server in your network
#       which requires password authentification.  The file should contain
#       exactly two lines:
#          username=user
#          password=*****
#       Please don't use blank spaces to separate the equal sign from the
#       user account name or password.
CREDFILE="/etc/autofs/keys/${KEY}"
# # !!!!!!!!!!!!!!!!! PAY ATTENTION TO the CIFS VERSION in MOUNTOPTS !!!!!!!!!!!!!!!!!!!!!!!!!!!
# https://www.raspberrypi.org/forums/viewtopic.php?t=201727 # https://www.raspberrypi.org/forums/viewtopic.php?t=211987
# http://krisko210.blogspot.com/2016/06/autofs-automount-nfs-share.html
# Note: Use cifs instead of smbfs:
MOUNTOPTS="-fstype=cifs,file_mode=0644,dir_mode=0755,nounix,uid=1000,gid=1000"
SMBCLIENTOPTS=""
for EACH in /bin /sbin /usr/bin /usr/sbin
do
        if [ -x $EACH/smbclient ]
        then
                SMBCLIENT=$EACH/smbclient
                break
        fi
done
[ -x $SMBCLIENT ] || exit 1
if [ -e "${CREDFILE}" ]
then
        MOUNTOPTS=$MOUNTOPTS",credentials=${CREDFILE}"
        SMBCLIENTOPTS="-A "$CREDFILE
else
        SMBCLIENTOPTS="-N"
fi
$SMBCLIENT $SMBCLIENTOPTS -gL "${KEY}" 2>/dev/null \
   | awk -v key="$KEY" -v opts="${MOUNTOPTS}" -F'|' -- '
        BEGIN   { ORS=""; first=1 }
        /Disk/  { if (first) { print opts; first=0 };
                  gsub(/ /, "\\ ", $2);
                  sub(/\$/, "\\$", $2);
                  print " \\\n\t /" $2, "://" key "/" $2 }
        END     { if (!first) print "\n"; else exit 1 }
        '
</sxh>
<sxh bash; gutter: false>
chmod 755 /etc/auto.<mysambaserver>-cifs
</sxh>

This file is a slightly modified version of the file auto.smb which usually comes as part of the autofs package. You need to modify the line defining the mountopts above and change userid and groupid to the uid/gid of your personal account.

===== key file =====

Now you have to give autofs the credentials needed to access shares on your network. To do this create a key file
<sxh bash; gutter: false>
mkdir -pv /etc/autofs/keys/
vim /etc/autofs/keys/<mysambaserver.local>
</sxh>
<sxh bash; title: /etc/autofs/keys/mysambaserver.local>
username=<myusername>
password=<myPassWord>
</sxh>
<sxh bash; gutter: false>
chown root:root /etc/autofs/keys/<mysambaserver.local>
chmod 600 /etc/autofs/keys/<mysambaserver.local>
</sxh>

===== Master-Map =====

The maps to be monitored are specified in this file.
Execute the following command to append the line “/home/myusername/mnt/cifs /etc/auto.mysambaserver-cifs –timeout=60” at the end of the /etc/auto.master file:
<sxh bash; gutter: false>
echo "/home/<myusername>/mnt/cifs /etc/auto.<mysamabaserver>-cifs --timeout=60 --ghost" >>/etc/auto.master
</sxh>

The syntax here is: <Directory> <Map-File> [Parameter]
The shares should be unmounted after an inactivity of 60 seconds (–timeout=60) and empty directories should be created for the individual shares before mounting (–ghost).

===== Debugging =====

for debugging output stop the daemon and interactively start autofs with verbose output enabled
<sxh bash; gutter: false>
service autofs stop
automount -f -v
</sxh>
You can restart autofs with
<sxh bash; gutter: false>
service autofs start
</sxh>

===== Test =====

Use the following command to test if your setup is working
<sxh bash; gutter: false>
ls -als /home/<myusername>/mnt/cifs/<mysambaserver.fqdn>/<share-name>
</sxh>

----
~~DISCUSSION~~