[PLUG] Moving a user from workstation to portable

[Kyle Hayes]

On Friday 05 December 2003 16:37, Rich Shepard wrote:
>   My fiancee wants to work on her laptop either connected to the network or
> off-line. There's no problem setting up her /home directory and getting
> three of the four main apps she uses running as stand-alone installations:
> mozilla, openoffice.org and jpilot. My question is how to configure her
> mail service (she likes sylpheed).
>
>   On the workstation, all /home directories are nfs-mounted from the
> server. So her mail is on the server and she is able to send and receive
> with no problems.
>
>   On the laptop, connected to the network, what do I need to do so she can
> collect mail from the server when she wants it? This is new territory for
> me so expect some questions. :-)

I set my wife up with a lap top in a similar manner, but I think the 
restrictions might be different.

I set up a small WAP on my local LAN (it's going behind it's own firewall 
soon) and NFS exported the home directory for her.  I set up POP on the 
server so she could get her email.  Because her home directory is staying on 
the server, I can just use POP and not IMAP.

It seems to work out fine though I think I'll go to 802.11g as soon as I can 
afford it (and the Linux drivers work).  The latency is noticably higher than 
my wired network and the bandwidth is not great.  But it was _cheap_!

The big difference here is that my wife _only_ uses the laptop from home, i.e. 
she is effectively always on the LAN.  I use the laptop offline and remotely 
all the time, but I don't have a problem with SSH etc.

My biggest goals was to make sure that she never ended up with two copies of 
her mail or her other data.

When would your fiancee collect email?  When she's not at home, is she 
completely offline?  If she needs to get and handle mail while she's remote, 
then something like IMAP or APOP might be the best bet (POP is not encrypted 
or particularly secure, hmm, not sure if IMAP is either).

You could get the email to the laptop a number of ways.  If you want to make 
sure that everything works (while email might not flow, nothing errors out), 
this might work (untested, use with caution, do not drive heavy machinery, I 
am not a system admin, nor do I play one on TV, etc. etc.):

Set up a simple POP server on the server.

Write a little wrapper script for fetchmail on the laptop.  Have it run every 
ten minutes or so.  _Iff_ the network is up, have it contact the server and 
get the mail.  If the network is not up, it just quietly goes back to sleep.  
Actually I think that fetchmail might be able to do this on its own, I cannot 
remember.

Set up Postfix/<MTA of choice> on the laptop.  Aim Sylpheed at it for 
_sending_ mail.  I'm not sure of all the nuances, but I'm pretty sure that 
Postfix comes out of the box with a sample config that would handle a 
intermittently connected machine.  Where do you route outgoing mail?  Postfix 
should queue mail until it is triggered to sent it away.

Setup Sylpheed to real new email from /var/spool/mail or the local equivalent. 
I.e. wherever fetchmail is going to put it.

This way she could always check for mail and send mail, even while offline.  
She won't get mail quite as quickly, but it should be able to queue just fine 
on the server.  She'll be able to send mail at any point, but it won't make 
it off the laptop and into the wide world until she's online.

What are her interactivity requirements?  If she is online, but not on your 
internal LAN sometimes, then maybe a carefully protected IMAP server would be 
best?

I'm probably going to be setting up a VPN tunnel from my laptop through my 
firewall into my DMZ so that I can access my internal services without having 
to expose them directly through the firewall.  I've done chroot servers and 
the like and it wasn't fun.  Most everyone I work with has wireless or a LAN 
at home or in the office.  Thus, I can be on the Internet nearly anywhere.

Best,
Kyle