[SOLVED] Script to generate SSH Banner MOTD

geforce · 04-18-2010, 12:39 PM

Hi All

I want to automate my System-installation. So i try to make a Script that will generate the /etc/motd. Now i have the Problem that the script has some variables and after the "Hostname, OS, HW, IP" the "stars" are anyware, but not there they should. The most problem is the $OS this string can verry long or verry short be. Fedora release 12 (Constantine) or RedHat 5.4

Can anybody tell me what i can do that after the variables place the "stars" on the write position?

Script

Code:

#!/bin/bash


INSTDATE=$(date +%F)
HOSTNAME=$(hostname)
OSRELASE=$(cat /etc/*release | head -1)
OSDETECT="i-have-to-define"
IPADDRES=$(ifconfig eth0 | grep -o '[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*' | head -1)


cat << End-of-Message > /etc/motd
    * * * * * * * * * * * * *:  W A R N I N G  :* * * * * * * * * * * * * *
    *THIS SYSTEM IS RESTRICTED TO AUTHORIZED USERS FOR AUTHORIZED USE ONLY*
    *   UNAUTHORIZED ACCESS IS STRICTLY PROHIBITED AND MAY BE PUNISHED    *
    * * * * * * * * * * * * *:  W A R N I N G  :* * * * * * * * * * * * * *
    *                                                          $INSTDATE *
    *           Hostname:       $HOSTNAME                                 *
    *           OS:             $OSRELASE                                 *
    *           HW:             $OSDETECT                                 *
    *           IP:             $IPADDRES                                 *
    *                                                                     *
    *           Contact:        Company                                   *
    *                           Street                                    *
    *                           Country                                   *
    *           Administrator:  NAME                                      *
    *                                                                     *
    *           State:          Productive                                *
    ***********************************************************************
End-of-Message

Should be looks

Code:

oot@localhost's password: 
Last login: Sun Apr 18 19:22:52 2010 from localhost

    * * * * * * * * * * * * *:  W A R N I N G  :* * * * * * * * * * * * * *
    *THIS SYSTEM IS RESTRICTED TO AUTHORIZED USERS FOR AUTHORIZED USE ONLY*
    *   UNAUTHORIZED ACCESS IS STRICTLY PROHIBITED AND MAY BE PUNISHED    *
    * * * * * * * * * * * * *:  W A R N I N G  :* * * * * * * * * * * * * *
    *							       2010-04-18 *
    *		Hostname:	localhost.localdomain			  *
    *		OS:		Fedora release 12 (Constantine)		  *
    *		HW:		i-have-to-define	 		  *
    *		IP:		10.10.10.10				  *
    *									  *
    *		Contact:	Company          			  *
    *				Street          	                  *
    *				Country     				  *
    *		Administrator:	NAME					  *
    *									  *
    *		State:		Productive				  *
    ***********************************************************************

thx

Tinkster · 04-18-2010, 12:56 PM

Use awk, with printf and formatting.

colucix · 04-18-2010, 12:58 PM

Just a thought: instead of cat you may try printf and format every line of the message accordingly. For example, the OS line should be given by

Code:

printf "    *           %-16s%-42s*\n" "OS:" "$OSRELASE"

An additional note: to retrieve the OS field, the "cat /etc/*release" is not a strong method. For example on my OpenSuse I have two files:

Code:

$ ls /etc/*release
/etc/lsb-release  /etc/SuSE-release

where the first line of the first file is

Code:

LSB_VERSION="core-2.0-noarch:core-3.2-noarch:core-2.0-ia32:core-3.2-ia32"

maybe not what you want. You can try with the following command, which is available on most linux distributions nowadays:

Code:

lsb_release -sd

Moreover take in mind that on some systems the file is not called something-release, but something-version.

geforce · 04-18-2010, 01:14 PM

Thx colucix, verry helpfull.

i try with awk and printf with variables but the solution to use printf line per line terrific!!. So simple that overlooked. Thx Thx

On my Fedora I have 3 Files but in all the Files are the same. So i make this pipe head -1... on my CentOS and RedHat's only one File.
I'm verry glad that you note me about this files.

Code:

[root@localhost ~]# ls /etc/*release
/etc/fedora-release  /etc/redhat-release  /etc/system-release

Code:

[root@localhost ~]# cat /etc/*release
Fedora release 12 (Constantine)
Fedora release 12 (Constantine)
Fedora release 12 (Constantine)

Tinkster · 04-18-2010, 01:21 PM

So this is solved? Please mark it as such.

geforce · 04-18-2010, 01:24 PM

Hi Tinkster..
i try and if there some problems i will ask the gurus again.
when i finished i will post the soultion and then will mark as solved.

thx

geforce · 04-18-2010, 04:26 PM

special thanks to colucix

I have now my Script. Works very well.
First i want to use the /etc/*release. For my Company works.
But in future if I know which i have to use i will change.

the "lsb_release -sd" command is not implement on my system, so it is not the better solution.

THX ALL

Code:

#!/bin/bash

FILE="/home/user/tmp/motd"
INSTDATE=$(date +%F)
HOSTNAME=$(hostname)
OSRELASE=$(cat /etc/*release | head -1)
OSDETECT="i-have-to-define"
#IPADDRES=$(ifconfig eth0 | grep -o '[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*' | head -1)
ETHERADD=$(ifconfig |grep -e ^[a-z] |grep -v lo | awk '{ printf $1 FS}')


if [ -w $FILE ]
	then
		if [[ -n `egrep -o '[0-9]+++-[0-9]++-[0-9]++' $FILE` ]]
		then
			IDATE=$(egrep -o '[0-9]+++-[0-9]++-[0-9]++' $FILE)
			echo "$FILE was in past $IDATE altered" 
			echo "Will be saved as .rpmsave"
			FILE=$FILE.rpmsave
		fi
	else
	    	logger -p local0.warn -t ME "`id -un` is not allowed to edit $FILE"
	    	echo "File is not Writeable. You are Not allowed to chance Motd"
		echo "Will be saved as .rpmsave"
		FILE=$FILE.rpmsave
fi


cat << End-of-Message > $FILE
`echo -en "\033[1;31m"`
    * * * * * * * * * * * * *:  W A R N I N G  :* * * * * * * * * * * * * *
    *THIS SYSTEM IS RESTRICTED TO AUTHORIZED USERS FOR AUTHORIZED USE ONLY*
    *   UNAUTHORIZED ACCESS IS STRICTLY PROHIBITED AND MAY BE PUNISHED    *
    * * * * * * * * * * * * *:  W A R N I N G  :* * * * * * * * * * * * * *
    *							       $INSTDATE *
End-of-Message

printf "    *           %-16s%-42s*\n" "Hostname:" "$HOSTNAME" >>$FILE
printf "    *           %-16s%-42s*\n" "OS:"	   "$OSRELASE" >>$FILE
printf "    *           %-16s%-42s*\n" "HW:" 	   "$OSDETECT" >>$FILE
#printf "    *           %-16s%-42s*\n" "IP:" 	   "$IPADDRES" >>$FILE

for i in $ETHERADD
do
	IP=$(ifconfig $i | grep -o '[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*' | head -1)
	printf "    *           %-16s%-42s*\n" "IP $i"      "$IP" >>$FILE
done

cat << End-of-Message >> $FILE
    *									  *
    *		Contact:	Company		 			  *
    *				Street		 			  *
    *				Country		 			  *
    *		Administrator:	NAME					  *
    *									  *
    *		Status:		Productive				  *
    ***********************************************************************
`echo -en "\033[0m"`
End-of-Message