I recently needed to find out the IP address of a test machince on the network.
The machince was set up DCHP and every time it rebooted I needed to know what the IP was, so I wrote this little script.
What this script does is send me an email with the IP address and some other information I found useful.
A coulple of things you need, Mutt installed and fuctioning and access to the /etc/rc.local file.
Copy this script into a file called rebootscript.sh
#!/bin/bash
echo "Reboot from Test Machine" > /tmp/rrmessage.txt
echo -e >> /tmp/rrmessage.txt
hostname >> /tmp/rrmessage.txt
echo -e >> /tmp/rrmessage.txt
/sbin/ifconfig eth0 >> /tmp/rrmessage.txt
uname -a >> /tmp/rrmessage.txt
echo -e >> /tmp/rrmessage.txt
cat /etc/issue >> /tmp/rrmessage.txt
mutt -s "Reboot Report" YourEmail@YourServer.com < /tmp/rrmessage.txt
Then chmod +x rebootscript.sh
Now move the rebootscript.sh to where ever you keep your startup scripts.
Now gedit /etc/rc.local and add the /path/to/scripts/rebootscript. sh to the end of the file.
Every time the system reboots you will get a nice little email like this.
Subject: Reboot Report
Reboot from Test Machine
TESTcentos64-bit
eth0 Link encap:Ethernet HWaddr 90:24:55:5A:2A:4D
inet addr:192.168.1.101 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:32 errors:0 dropped:0 overruns:0 frame:0
TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4311 (4.2 KiB) TX bytes:3250 (3.1 KiB)
Interrupt:169 Memory:fe8f0000-fe900000
Linux TESTcentos64-bit 2.6.18-194.8.1.el5 #1 SMP Thu Jul 1 19:04:48 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux
CentOS release 5.5 (Final)
This will also let you know when the server has had an unplanned reboot.
Enjoy,