How to disable a specific command(s) for a certain user.

Please follow the below steps to disable a specific command(s) for a certain user.

# su - hari
$ which rm (Here rm command as an example)
$ mkdir ~/bin
$ ln -s /bin/* ~/bin/ (/bin is the PATH for rm)
$ rm -rf ~/bin/rm

Take the output of $PATH for this user

$ echo $PATH > MyPATH.txt
Edit this file and replace /bin with ~/bin

Login as root

$ su -
# cat /home/hari/MyPATH.txt >> /home/hari/.bashrc

Change the permission of /home/hari/.bashrc
# chmod 444 /home/hari/.bashrc
# chattr +i /home/hari/.bashrc


That's all.
But the user can reset the PATH variable anytime to overcome this.
Please comment with alternatives for this.

Disable Media Check for cdrom

Grub.conf
dma=off apci=off apm=off

/etc/hdparm.conf
command_line {
hdparm -d1 /dev/cdrom
}

command_line {
hdparm -d1 /dev/cdrom1
}

sysctl.conf
dev.cdrom.check_media = 0

MySQL Compilation

# groupadd mysql
# useradd -g mysql -c "MySQL Server" mysql
# tar zxf mysql-5.0.45.tar.gz
# cd /usr/local/src/ mysql-5.0.45
# .chown -R root.root *
# ./configure \--prefix=/usr/local/mysql \--localstatedir=/usr/local/mysql/data \--disable-maintainer-mode \--with-mysqld-user=mysql \--with-unix-socket-path=/tmp/mysql.sock \--without-comment \--without-debug \

# groupadd mysql
# useradd -g mysql -c "MySQL Server" mysql
# tar zxf mysql-5.0.45.tar.gz
# cd /usr/local/src/ mysql-5.0.45
# chown -R root.root *
# ./configure \--prefix=/usr/local/mysql \--localstatedir=/usr/local/mysql/data \--disable-maintainer-mode # \--with-mysqld-user=mysql \--with-unix-socket-path=/tmp/mysql.sock \--without-comment \--without-debug \--without-bench
# make && make install
# ./scripts/mysql_install_db
# chown -R root:mysql /usr/local/mysql
# chown -R mysql:mysql /usr/local/mysql/data
# cp support-files/my-medium.cnf /etc/my.cnf
# chown root:sys /etc/my.cnf
# chmod 644 /etc/my.cnf
# echo "/usr/local/mysql/lib/mysql" >> /etc/ld.so.conf
# ldconfig
# cp ./support-files/mysql.server /etc/rc.d/init.d/mysql
# chmod +x /etc/rc.d/init.d/mysql
# /sbin/chkconfig --level 3 mysql on
# cd /usr/local/mysql/bin
# for file in *; do ln -s /usr/local/mysql/bin/$file /usr/bin/$file;

# /etc/init.d/mysql start

Open multiple tabs with Gnome-Tminal

gnome-terminal --geometry=125x75 --tab -e "ssh
192.168.0.67 -l myuser" --tab -e "ssh
192.168.0.45 -l root" --tab -e "ssh 192.168.0.88 -l
root" --tab -e "ssh 192.168.1.145 -l root -p 22999"

Set date from CLI

# date 030710532008
date
Fri Mar 7 10:53:01 IST 2008

Bugzilla installation

Reference
bugzilla.org
Download the latest Stable Release
# cd /usr/local/src
# wget http://ftp.mozilla.org/pub/mozilla.org/webtools/bugzilla-3.0.3.tar.gz
# tar xzf bugzilla-3.0.3.tar.gz
# cd bugzilla-3.0.3
First,run the checksetup.pl script to check for any dependant packages that need to be installed
# ./checksetup.pl --check-modules
NOTE: You must run any commands listed below as root.
***********************************************************************
* REQUIRED MODULES *
***********************************************************************
* Bugzilla requires you to install some Perl modules which are either *
* missing from your system, or the version on your system is too old. *
* *
* The latest versions of each module can be installed by running the *
* commands below. *
***********************************************************************
COMMANDS:
/usr/bin/perl -MCPAN -e 'install "Email::Send"'
/usr/bin/perl -MCPAN -e 'install "Template"'
/usr/bin/perl -MCPAN -e 'install "Email::MIME::Modifier"'
/usr/bin/perl -MCPAN -e 'install "Date::Format"'
So run one by one
# /usr/bin/perl -MCPAN -e 'install "Email::Send"'
Fine
# /usr/bin/perl -MCPAN -e 'install "Template"'
Fine
# /usr/bin/perl -MCPAN -e 'install "Email::MIME::Modifier"'
Fine
# /usr/bin/perl -MCPAN -e 'install "Date::Format"
Fine
Now configure Database and Apache settings
# cd /usr/local/src/bugzilla-3.0.3
# vi localconfig

$create_htaccess = 1;
$webservergroup = 'nobody';
$db_driver = 'mysql';
$db_host = 'localhost';
$db_name = 'bugs';
$db_user = 'bugs';
$db_pass = 'secret';
$db_port = 3306;
$db_sock = '/tmp/mysql.sock';
$db_check = 1;
$index_html = 0;
$cvsbin = '/usr/bin/cvs';
$interdiffbin = '/usr/bin/interdiff';
$diffpath = '/usr/bin';

Re-run checksetup.pl
# ./checksetup.pl
Now it will create the database and WebServer data like .htaccess files.
MySQL
Allow large attachments
# vi /etc/my.cnf
max_allowed_packet=1M
Allow small words in full-text indexes
ft_min_word_len=2
Add a user to MySQL
# mysql -u root -pmysql
mysql> GRANT SELECT, INSERT, UPDATE, DELETE, INDEX, ALTER, CREATE, LOCK TABLES, CREATE TEMPORARY TABLES, DROP, REFERENCES ON bugs.* TO bugs@localhost IDENTIFIED BY 'secret';
Query OK, 0 rows affected (0.04 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)
Configure Apache
First create a soft link to Bugzilla in your WebServer's DocumentRoot
# cd /var/www/html
# ln -s /usr/local/src/bugzilla-3.0.3 bugzilla
# vi /usr/local/apache/conf/httpd.conf

AddHandler cgi-script .cgi
Options +Indexes +ExecCGI
DirectoryIndex index.cgi
AllowOverride Limit

# /usr/local/apache/bin/apachectl restart
Now it should up at http://localhost/bugzilla

Log Server using Syslog-NG

Server - RHEL 5
Stop Syslog and turn it off through Run Levels

# service syslog stop
# chkconfig syslog off

Download syslog-ng
# cd /usr/local/src
# wget http://www.balabit.com/downloads/files/eventlog/0.2/eventlog-0.2.5.tar.gz

# tar xzf eventlog-0.2.5.tar.gz
# cd eventlog-0.2.5
# ./configure --prefix=/usr/local/eventlog
# make
# make install

# cd /usr/local/src
# wget http://www.balabit.com/downloads/files/libol/0.3/libol-0.3.18.tar.gz
# tar xzf libol-0.3.18.tar.gz
# cd libol-0.3.18
# ./configure --prefix=/usr/local/libol
# make
# make install

# cd /usr/local/src
# wget http://www.balabit.com/downloads/files/syslog-ng/sources/2.0/src/syslog-ng-2.0.6.tar.gz
# tar xzf syslog-ng-2.0.6.tar.gz
# cd syslog-ng-2.0.6

# export PKG_CONFIG_PATH=/usr/local/eventlog/lib/pkgconfig
# ./configure --prefix=/usr/local/syslog-ng --with-libol=/usr/local/libol/
# make
# make install

# cd /usr/local/syslog-ng
# mkdir etc
# cd etc
# vi syslog-ng.conf

### Refer http://www.campin.net/syslog-ng.conf
options {
keep_hostname(yes);
long_hostnames(off);
sync(1);
log_fifo_size(1024);
};

source src {
pipe("/proc/kmsg");
unix-stream("/dev/log");
internal();
udp();
tcp(port(5140) keep-alive(yes));
};

destination authlog { file("/var/log/syslog-ng/auth.log"); };
destination syslog { file("/var/log/syslog-ng/syslog"); };
destination cron { file("/var/log/syslog-ng/cron.log"); };
destination daemon { file("/var/log/syslog-ng/daemon.log"); };
destination kern { file("/var/log/syslog-ng/kern.log"); };
destination lpr { file("/var/log/syslog-ng/lpr.log"); };
destination user { file("/var/log/syslog-ng/user.log"); };
destination uucp { file("/var/log/syslog-ng/uucp.log"); };

destination mail { file("/var/log/syslog-ng/mail.log"); };
destination maillog { file("/var/log/syslog-ng/maillog"); };
destination mailinfo { file("/var/log/syslog-ng/mail.info"); };
destination mailwarn { file("/var/log/syslog-ng/mail.warn"); };
destination mailerr { file("/var/log/syslog-ng/mail.err"); };

destination debug { file("/var/log/syslog-ng/debug"); };
destination messages { file("/var/log/syslog-ng/messages"); };

destination console { usertty("root"); };

destination console_all { file("/dev/tty8"); };

filter f_attack_alert {
match("attackalert");
};

filter f_ssh_login_attempt {
program("sshd.*")
and match("(Failed|Accepted)")
and not match("Accepted (hostbased|publickey) for (root|zoneaxfr) from (10.4.3.1)");
};

filter f_authpriv { facility(auth, authpriv); };
filter f_syslog { not facility(auth, authpriv) and not facility(mail); };
filter f_cron { facility(cron); };
filter f_daemon { facility(daemon); };
filter f_kern { facility(kern); };
filter f_lpr { facility(lpr); };
filter f_mail { facility(mail); };
filter f_user { facility(user); };
filter f_uucp { facility(cron); };

filter f_news { facility(news); };

filter f_debug { not facility(auth, authpriv, news, mail); };
filter f_messages { level(info .. warn)
and not facility(auth, authpriv, cron, daemon, mail, news); };
filter f_emergency { level(emerg); };

filter f_info { level(info); };
filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };

filter f_cnews { level(notice, err, crit) and facility(news); };
filter f_cother { level(debug, info, notice, warn) or facility(daemon, mail); };

filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };

filter f_cnews { level(notice, err, crit) and facility(news); };
filter f_cother { level(debug, info, notice, warn) or facility(daemon, mail); };

log { source(src); filter(f_authpriv); destination(authlog); };
log { source(src); filter(f_syslog); destination(syslog); };
log { source(src); filter(f_cron); destination(cron); };
log { source(src); filter(f_daemon); destination(daemon); };
log { source(src); filter(f_daemon); destination(messages); };
log { source(src); filter(f_kern); destination(messages); };
log { source(src); filter(f_lpr); destination(lpr); };
log { source(src); filter(f_mail); destination(mail); };
log { source(src); filter(f_user); destination(user); };
log { source(src); filter(f_user); destination(messages); };
log { source(src); filter(f_uucp); destination(uucp); };
log { source(src); filter(f_mail); destination(maillog); };
log { source(src); filter(f_mail); filter(f_info); destination(mailinfo); };
log { source(src); filter(f_mail); filter(f_warn); destination(mailwarn); };
log { source(src); filter(f_mail); filter(f_err); destination(mailerr); };
log { source(src); filter(f_messages); destination(messages); };
log { source(src); filter(f_emergency); destination(console); };

destination HOSTBASED {
file("/var/log/syslog-ng/HOSTBASED/$HOST/$YEAR/$MONTH/$DAY/$FACILITY_$HOST_$YEAR_$MONTH_$DAY"
owner(root) group(root) perm(0600) dir_perm(0700) create_dirs(yes)
);
};

log {
source(src);
destination(HOSTBASED);
};


# mkdir /var/log/syslog-ng

Started syslog-ng daemon
# /usr/local/syslog-ng/sbin/syslog-ng

Client - RHEL 5

Stop Syslog and turn it off through Run Levels

# service syslog stop
# chkconfig syslog off

Download syslog-ng
# cd /usr/local/src
# wget http://www.balabit.com/downloads/files/eventlog/0.2/eventlog-0.2.5.tar.gz
# tar xzf eventlog-0.2.5.tar.gz
# cd eventlog-0.2.5
# ./configure --prefix=/usr/local/eventlog
# make
# make install

# cd /usr/local/src
# wget http://www.balabit.com/downloads/files/libol/0.3/libol-0.3.18.tar.gz
# tar xzf libol-0.3.18.tar.gz
# cd libol-0.3.18
# ./configure --prefix=/usr/local/libol
# make
# make install

# cd /usr/local/src
# wget http://www.balabit.com/downloads/files/syslog-ng/sources/2.0/src/syslog-ng-2.0.6.tar.gz
# tar xzf syslog-ng-2.0.6.tar.gz
# cd syslog-ng-2.0.6

# export PKG_CONFIG_PATH=/usr/local/eventlog/lib/pkgconfig
# ./configure --prefix=/usr/local/syslog-ng --with-libol=/usr/local/libol/
# make
# make install

# cd /usr/local/syslog-ng
# mkdir etc
# cd etc
# vi syslog-ng.conf

Reference - http://www.campin.net/syslog-ng.conf

options {
keep_hostname(yes);
long_hostnames(off);
sync(1);
log_fifo_size(1024);
};

source src {
pipe("/proc/kmsg");
unix-stream("/dev/log");
internal();
udp();
tcp(port(5140) keep-alive(yes));
};

destination loghost { tcp("192.168.0.111" port(5140)); };

filter f_attack_alert {
match("attackalert");
};

filter f_ssh_login_attempt {
program("sshd.*")
and match("(Failed|Accepted)")
and not match("Accepted (hostbased|publickey) for (root|zoneaxfr) from (10.4.3.1)");
};

filter f_authpriv { facility(auth, authpriv); };
filter f_syslog { not facility(auth, authpriv) and not facility(mail); };
filter f_cron { facility(cron); };
filter f_daemon { facility(daemon); };
filter f_kern { facility(kern); };
filter f_lpr { facility(lpr); };
filter f_mail { facility(mail); };
filter f_user { facility(user); };
filter f_uucp { facility(cron); };

filter f_news { facility(news); };

filter f_debug { not facility(auth, authpriv, news, mail); };
filter f_messages { level(info .. warn)
and not facility(auth, authpriv, cron, daemon, mail, news); };
filter f_emergency { level(emerg); };

filter f_info { level(info); };
filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };

filter f_cnews { level(notice, err, crit) and facility(news); };
filter f_cother { level(debug, info, notice, warn) or facility(daemon, mail); };
filter f_emergency { level(emerg); };

filter f_info { level(info); };
filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };

filter f_cnews { level(notice, err, crit) and facility(news); };
filter f_cother { level(debug, info, notice, warn) or facility(daemon, mail); };

log { source(src); filter(f_authpriv); destination(loghost); };
log { source(src); filter(f_syslog); destination(loghost); };
log { source(src); filter(f_daemon); destination(loghost); };
log { source(src); filter(f_kern); destination(loghost); };
log { source(src); filter(f_lpr); destination(loghost); };
log { source(src); filter(f_mail); destination(loghost); };
log { source(src); filter(f_user); destination(loghost); };
log { source(src); filter(f_uucp); destination(loghost); };
log { source(src); filter(f_mail); destination(loghost); };
log { source(src); filter(f_mail); filter(f_info); destination(loghost); };

filter f_emergency { level(emerg); };

filter f_info { level(info); };
filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };

filter f_cnews { level(notice, err, crit) and facility(news); };
filter f_cother { level(debug, info, notice, warn) or facility(daemon, mail); };

log { source(src); filter(f_authpriv); destination(loghost); };
log { source(src); filter(f_syslog); destination(loghost); };
log { source(src); filter(f_daemon); destination(loghost); };
log { source(src); filter(f_kern); destination(loghost); };
log { source(src); filter(f_lpr); destination(loghost); };
log { source(src); filter(f_mail); destination(loghost); };
log { source(src); filter(f_user); destination(loghost); };
log { source(src); filter(f_uucp); destination(loghost); };
log { source(src); filter(f_mail); destination(loghost); };
log { source(src); filter(f_mail); filter(f_info); destination(loghost); };
log { source(src); filter(f_mail); filter(f_warn); destination(loghost); };
log { source(src); filter(f_mail); filter(f_err); destination(loghost); };
log { source(src); filter(f_messages); destination(loghost); };
log { source(src); filter(f_emergency); destination(loghost); };

destination std {
file("/var/log/HOSTS/$HOST/$YEAR/$MONTH/$DAY/$FACILITY_$HOST_$YEAR_$MONTH_$DAY"
owner(root) group(root) perm(0600) dir_perm(0700) create_dirs(yes)
);
};

log {
source(src);
destination(std);
};


# mkdir /var/log/syslog-ng

Started syslog-ng daemon
# /usr/local/syslog-ng/sbin/syslog-ng