pantz.org banner
The SheevaPlug backup mail server
Posted on 06-26-2009 02:35:28 UTC | Updated on 06-26-2009 02:51:39 UTC
Section: /hardware/plugcomputer/ | Permanent Link

What is a SheevaPlug? It is a network appliance that is fully enclosed in an AC power plug or AC adapter. It has a gigabit Ethernet port, SD memory slot, usb port, and mini-usbport. You can plug it right into the wall just like an ac adapter. All for $99.

It comes with 512 Meg ram and 512 Meg of flash based disk space. It runs a ARM processor and comes with Ubuntu Linux installed.

More info about the SheevaPlug can be found here.

I used this little plug computer to setup a backup mail server. You could use it for just about anything you like since it runs a full Linux distribution. Here is the basic setup I used to get everything going.

Connect to the SheevaPlug from a linux box using the usb cable that came in the box. This connection will be your serial console (USBtoSerial). To get the usb serial thing going I had to insert a few modules on my Linux box. Everything worked fine after that. I have also read that you can just plug it in and it will get a DHCP address off the network if you have a DHCP server. Then you can just ssh in from there.

sudo modprobe usbserial
sudo modprobe ftdi_sio vendor=0x9e88 product=0x9e8f

Install the simple call up (cu) program to connect to the emulated serial port ttyUSB1. Then connect.

sudo apt-get install cu
cu -s 115200 -l /dev/ttyUSB1

Login as root with the default password.

Login: root
Pass: nosoup4u

Change your root password

passwd

Add a new user.

adduser newuser

Use visudo and insert the line below to give your new user full sudo privs.

# add user in visudo
newuser    ALL=(ALL) ALL

Then turn on the setuid bit on the sudo program so you can actually use sudo. Sudo will not let you sudo to root if you don't do this.

chmod u+s /usr/bin/sudo

Edit /etc/network/interfaces. Comment out DHCP line. Put in static ip info.

# iface eth0 inet dhcp
auto eth0
iface eth0 inet static
address 192.168.1.60
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.1

Restart networking.

/etc/init.d/networking restart

Edit /etc/resolv.conf and put in your ISP's DNS servers

domain yourdomain.org
search yourdomain.org
nameserver 192.168.1.1

The Ubuntu 9.04 that comes with the plug computer puts it's apt-get cache dir on a temporary file system. It's missing a dir so apt-get will not work until you make the dir. This line is in the /etc/rc.local file but it does not seem to execute on boot for some reason.

mkdir -p /var/cache/apt/archives/partial/

Install the Postfix SMTP server. This is the main reason for this box. You will have to put in your Posfix configs here. If you need examples see the menu on this site in the Postfix section. You can also search this site for the word Postfix.

apt-get install postfix
apt-get clean all
# put in your config files
/etc/init.d/postfix start

I use procmail as my MDA so I'll install it.

apt-get install procmail
apt-get clean all

Install ddclient so we can update the dynamically changing ip of our server.

apt-get install ddclient
apt-get clean all

Edit /etc/default/ddclient file. Change run_daemon to true and daemon interval to what you want.

run_daemon="true"
daemon_interval="1800"

Then copy over your /etc/ddclient.conf file. An example one is below. This example uses a custom domain in the example. The backup mail server.

daemon=1800                     # check every 600 seconds
syslog=yes                      # log update msgs to syslog
mail=root                       # mail all msgs to root
mail-failure=root               # mail failed update msgs to root
pid=/var/run/ddclient.pid       # record PID in file.
cache=/var/run/ddclient.cache   # Cache file
ssl=yes                         # use ssl-support.
use=web
login=dynloginname              # default login
password=xxxxxx                 # default password
protocol=dyndns2
server=members.dyndns.org
custom=yes, backupmail.yourdomain.org

Install OpenNTPd. For some reason OpenNTPd needs a date near the real date to work. So we will set one close to the real date. Then update the hardware clock.

date 012618002009
hwclock -w
apt-get install openntpd

Edit the /etc/default/openntpd file and put in the -s option. This is so OpenNTPd will set the time on start.

DAEMON_OPTS="-s"

Restart OpenNTPd.

/etc/init.d/openntpd restart

Install pflogsumm because I like mail stats. Install mailx because the mail package is to big and mailx does what we need. This will make a symlink to mail.

apt-get install pflogsumm mailx

Run crontab -e and put this line in cron for pflogsum to run stats each night.

# crontab -e
15 0 * * * /usr/sbin/pflogsumm -d yesterday /var/log/mail.log 2>&1 |/usr/bin/mail -s "`uname -n` daily mail stats" root

The Linux build for the SheevaPlug does not have iptables by default. You could put an updated kernel in if you want it but let's keep this simple. We just want to filter hosts that connect to sshd. So we can do it with tcp wrappers. We will allow only hosts who's DNS PTR records (reverse look up) resolve to my.isp.org. Edit the /etc/hosts.allow file and put this in changing it for your ISP. Remember to allow your local hosts to connect ot sshd also.

sshd : .my.isp.org : allow
sshd : 192.168.1. : allow
sshd : localhost : allow
sshd : ALL : deny

Last but not least. Remember to forward port 22 and 25 on your ISP's router to the internal static ip you gave your SheevaPlug.

Just reboot and test. I can say it works great for me. Cheap, silent, very low power, Linux. What more could you ask for?

Reddit!

Related stories


RSS Feed RSS feed logo

About


3com

3ware

alsa

alsactl

alsamixer

amd

android

apache

areca

arm

ati

auditd

awk

badblocks

bash

bind

bios

bonnie

cable

carp

cat5

cdrom

cellphone

centos

chart

chrome

chromebook

cifs

cisco

cloudera

comcast

commands

comodo

compiz-fusion

corsair

cpufreq

cpufrequtils

cpuspeed

cron

crontab

crossover

cu

cups

cvs

database

dbus

dd

dd_rescue

ddclient

debian

decimal

dhclient

dhcp

diagnostic

diskexplorer

disks

dkim

dns

dos

dovecot

drac

dsniff

dvdauthor

e-mail

echo

editor

emerald

encryption

ethernet

expect

ext3

ext4

fat32

fedora

fetchmail

fiber

filesystems

firefox

firewall

flac

flexlm

floppy

flowtools

fonts

format

freebsd

ftp

gdm

gmail

gnome

google

gpg

greasemonkey

greylisting

growisofs

grub

hacking

hadoop

harddrive

hba

hex

hfsc

html

html5

http

https

hulu

idl

ie

ilo

intel

ios

iperf

ipmi

iptables

ipv6

irix

javascript

kde

kernel

kickstart

kmail

kprinter

krecord

kubuntu

kvm

lame

ldap

linux

logfile

lp

lpq

lpr

maradns

matlab

memory

mencoder

mhdd

mkinitrd

mkisofs

moinmoin

motherboard

mouse

movemail

mplayer

multitail

mutt

myodbc

mysql

mythtv

nagios

nameserver

netflix

netflow

nginx

nic

ntfs

ntp

nvidia

odbc

openbsd

openntpd

openoffice

openssh

openssl

openvpn

opteron

parted

partimage

patch

perl

pf

pfflowd

pfsync

photorec

php

pop3

pop3s

ports

postfix

power

procmail

proftpd

proxy

pulseaudio

putty

pxe

python

qemu

r-studio

raid

recovery

redhat

router

rpc

rsync

ruby

saltstack

samba

schedule

screen

scsi

seagate

seatools

sed

sendmail

sgi

shell

siw

smtp

snort

solaris

soundcard

sox

spam

spamd

spf

spotify

sql

sqlite

squid

srs

ssh

ssh.com

ssl

su

subnet

subversion

sudo

sun

supermicro

switches

symbols

syslinux

syslog

systemd

systemrescuecd

t1

tcpip

tcpwrappers

telnet

terminal

testdisk

tftp

thttpd

thunderbird

timezone

ting

tls

tools

tr

trac

tuning

tunnel

ubuntu

unbound

vi

vpn

wget

wiki

windows

windowsxp

wireless

wpa_supplicant

x

xauth

xfree86

xfs

xinearama

xmms

youtube

zdump

zeromq

zic

zlib