#
# ssh_nfs_mnt: A ssh+nfs hack to mount nfs dirs on a PC (e.g. mobile laptop).
#
# Usage:
#
#	ssh_nfs_mnt		(mount the shares)
#	ssh_nfs_mnt -w		(mount the shares and wait for ssh to finish)
#	ssh_nfs_mnt -u		(unmount the shares)
#
# You can also specify any of the parameters described below on the cmd
# line (after any -w or -u option), e.g.:
#
#	ssh_nfs_mnt nfs_dirs=/home nfs_server=runge@hyades0.lbl.gov
#
# Notes:
#
#	Since it does the local mounting, this script will run sudo(1)
#	when necessary.  Hopefully your sudo(1) will only ask for the
#	password the first time (i.e. subsequent sudo's will not need
#	the password unless a timeout of 5 mins is reached).
#
#	If you are not using an ssh-agent, you will need to type your
#	remote system password/passphrase twice (once for collecting
#	rpcinfo output and again for the actual port redir).
#
#	If your userid number (run the "id" command to see what it is)
#	differs between the remote NFS server and the local machine
#	you may not be able to write and/or read the mounted files.
#	If possible try to make the number of the userid and groupid be
#	the same on both machines.  Your mount(8) command may allow for
#	userid remapping.
#
#	REMEMBER: before unmounting (via the -u option), you must cd
#	every shell out of the mounted areas and no application can have
#	any mounted file open.  If you see 'device is busy' errors you
#	will know you forgot to do this.
#
#	Except under -w wait mode, the ssh port redir command does a
#	'sleep 60' so the mount performed by this script will have to
#	take place in that time period (note you may be prompted for a
#	password).  Also, if you unmount (-u) quickly, you will have to
#	wait for the 'sleep 60' by the ssh to finish and the ports freed.
#
#	For MacOS X (Darwin) you will need to make sure local servers nfs,
#	mountd, and portmap are NOT running before you run this script.
#	See the details below.  If you find your nfs client OS is in
#	the same boat as MacOS X, specify uname=Darwin on the cmdline.
#
#	For debugging output, use "-d" as the first argument.
#
#	Only tested for Linux NFS servers.
#	Only tested for Linux NFS clients.
#

nfs_server="hyades0.lbl.gov"	# user@hostname (passed to ssh) works also.
#
# nfs_server: this is used to ssh to the server machine.  Note on Darwin
# since the ssh must be run via sudo (for the low ports, portmapper 111,
# etc) you may always need to supply the "user@" part and/or supply a
# password (because ssh as root won't find your keys).  If SSH_AUTH_SOCK
# exists in the environment it will be used in the sudo.

nfs_ip="10.0.0.220"		# server IP relative to nfs_server.
#
# nfs_ip: Note localhost or 127.0.0.1 is another possibility here but
# that probably requires an edit of /etc/exportfs on the nfs server
# side to add 127.0.0.1 to a list, so it is likely better to use a real
# network interface IP here.

nfs_dirs="/opt/snf /home"	# The remote shares to mount.
#
# nfs_dirs: A comma separated list is also acceptable (e.g. if you
# specify the parmeter on the command line and want to avoid spaces).

mountpoint="$HOME/hyades0"	# Local directory to mount the shares in.
#mountpoint="/tmp/hyades0"
#mountpoint="/var/tmp/hyades0"
#
# Each share is a subdir of this directory, e.g.  /tmp/hyades0/opt/snf
# or $HOME/hyades0/opt/snf. Take your pick of the 3 suggestions above or
# make your own.  Note: the mountpoint dir should be on a local filesystem
# (your $HOME may not be...).

mount_opts=""			# Supply any extra mount(8) opts here.
#
# You may want to use mount_opts for performance reasons, e.g. over
# a high latency link.  See your OS mount(8), mount_nfs(8), or nfs(5)
# docs for more info.
#
# Consider: noatime, nodiratime, actimeo (or acregmin, acregmax, acdirmin,
# acdirmax), timeo, retrans, rdirplus, etc.  This example seems to give
# an improvement:
#
#	mount_opts=timeo=15,actimeo=300

# These are the default mount(8) options used, change them if you need to:
#
default_opts="tcp,nfsvers=3,rsize=8192,wsize=8192,intr,rw,nosuid"


sleep=60			# Time of the initial sleep(1) in the
				# remote ssh cmd, e.g: ssh .... 'sleep 60'
				# (not used in wait mode -w).

keepalive=30			# Period to send a "nfs ping" by running df(1).
				# (not used in wait mode -w).
# keepalive: Some NFS clients will disconnect the TCP connection after,
# say, 5 mins of inactivity.  If the ssh initial sleep has finished
# at that point the ssh connection will be closed.  We are screwed at
# that point because when NFS activity starts back up there is no ssh
# TCP tunnel to the server for it to reconnect through.  This option
# tries to keep the link active by running df(1) frequently enough
# (every keepalive seconds).  Set to 0 to disable.

# Port redirs for nfs and mountd port via ssh:
#
# port1 and port2 below are ssh redirection ports for nfs and mountd,
# respectively.
#
# These are fixed local ports for now, but this could cause problems
# with multiple instances of this script or hung redirs...
#
# You can use port1=NNNN, port2=MMMM on the command line to pick different
# ones if you need to.
#
# On Darwin (MacOS X) NFS clients port1 and port2 below will be not
# be used at all, the actual remote server ports will be used instead
# (i.e. 2049 -> remote:2049).  Of course this means those port numbers
# and also portmap 111 may not be in use locally (i.e. you cannot run
# the Darwin client as an NFS server at the same time).
#
port1=61001	# nfs    redirection port (e.g. 61001 -> remote:2049)
port2=61002	# mountd redirection port (e.g. 61002 -> remote:833)

# Misc. commands:
#
ssh=ssh		# you can override these too if you like.
sudo=sudo

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