Ajax (Asynchronous JavaScript and XML) allows You to make a lot of nice effects. Using rico and prototype libraries it is very simple to write some funnny game like this.
I wrote this javascript game in a few thanks to a removed post on http://www.janeirostudio.com website and the ImageMagik command
$ convert orchis_360.jpg -crop 90×90 orchis
to split the main image into 16 sub-images.
Yesterday I was requested to redirect the traffic to the 80 TCP port of an host to the TCP 8080 port of a second host just for some hours. Thanks to iptables it was been very easy.
First it’s better to enable port forwarding:
# echo 1 >/proc/sys/net/ipv4/ip_forward
Then here comes some iptables commands and rules:
# iptables -F
# iptables -X
# iptables -t nat -F
# iptables -t nat -X
# iptables -t mangle -F
# iptables -t mangle -X
# iptables -P INPUT ACCEPT
# iptables -P FORWARD ACCEPT
# iptables -P OUTPUT ACCEPT# iptables -t nat -A PREROUTING -p tcp -m tcp -d HOST1 –dport PORT1 -j DNAT –to-destination HOST2:PORT2
# iptables -t nat -A POSTROUTING -p tcp -d HOST2 –dport PORT2 -j MASQUERADE
If You like, just download this simple shell script.
To display the nat rule:
# iptables -t nat -n -L
many thanks to cyberciti.biz and Chris Siebenmann‘s wiki.
Install the software You need:
# apt-get install samba-common heimdal-clients winbind ntpdate ntp samba
set the right timezone and the righ system time
# /etc/init.d/ntp stop
# dpkg-reconfigure tzdata
# ntpdate your.domain.controller
then insert Your domain controller into the time servers list:
# vi /etc/ntp.conf
add in the right place the line
# You do need to talk to an NTP server or two (or three).
#server ntp.your-provider.example
server your.domain.controller
# /etc/init.d/ntp start
Edit Your file /etc/krb5.conf
# cat /etc/krb5.conf
[libdefaults]
default_realm = DOMAIN.NAME
clockskew = 300
[realms]
DOMAIN.NAME = {
kdc = your.domain.controller IP Address
admin_server = your.domain.controller IP Address
}
Edit Your file /etc/samba/smb.conf
# cat /etc/samba/smb.conf
[global]
realm = DOMAIN.NAME
workgroup = domain
security = ADS
idmap uid = 10000-20000
idmap gid = 10000-20000
template shell = /bin/bash
template homedir = /home/%D/%U
winbind use default domain = yes[homes]
valid users = %U
check your modification with
# testparm
and then
# mkdir /home/DOMAIN
Then edit the /etc/nsswitch.conf file:
passwd: files winbind
group: files winbind
#passwd: compat
#group: compat
Now issue the command:
# net ads join -U DomainAdminUsername -W DOMAIN.NAME
Ignoring the error notice saying something like “Unable to perform DNS Update”.
Then restart some services:
# /etc/init.d/samba restart
# /etc/init.d/winbind restart
And verify You have joined the Domain, e.g. asking for some data to be displayed:
# wbinfo -u |xargs getent passwd
… and remember to modify theese files
# cat /etc/pam.d/common-account:
account sufficient pam_winbind.so
account required pam_unix.so# cat /etc/pam.d/common-auth:
auth sufficient pam_winbind.so
auth required pam_unix.so use_first_pass# cat /etc/pam.d/common-session:
session required pam_mkhomedir.so skel=/etc/skel/ umask=0022
session sufficient pam_winbind.so
session required pam_unix.so
In order to give a static adress instead of the DHCP assigned one, You can chose bridge network in the mail VirtualBox Control panel for You host (in settings -> Network).
If during the boot You see the error
SIOCSIFADDR: no such device
eth0 ERROR …. etc….
maybe You have a wrong MAC address in your file /etc/udev/rules.d/70-persistent-net.rules matching the eth0 interface. So verify
Obviously the MAC address for this interface have to be the same!
VirtualBox is a very nice GPL alternative to vmWare if You are looking for a general-purpose x86 hardware virtualizer.
The VirtualBox Installation is very easy: in many case You have only to download the righ file (.rpm, .deb, etc…) and install it as a normal software package.
If You need to clone quickly a virtual host, stop this, then cd where your system are storing your virtual box hard disk and issue the command VBoxManage specifying the action (clonehd), the input file name (the virtual hard disk file), and the output file. E.G.
cd ~/.VirtualBox/HardDisks
VBoxManage clonehd vbox-lenny1.vdi vbox-lenny2.vdi
This command duplicates a registered virtual hard disk image to a new image file with
a new unique identifier (UUID), that will be shown at the end of the copy output:
VirtualBox Command Line Management Interface Version 2.2.2
(C) 2005-2009 Sun Microsystems, Inc.
All rights reserved.0%…10%…20%…30%…40%…50%…60%…70%…80%…90%…100%
Clone hard disk created in format ‘VDI’. UUID: 42bf1adb-e7f7-4993-b8e8-739aca77e092
Then, from Your VirtualBox main console, start the new host wizard, followin the defaults just to the point to specify Your hard disk. Here check for “Use existing hard disk” and browse to look for the file You have just created with the VBoxManage clonehd command.
Remember You have to click on the “Add” icon to see and import your new hard disk file.
Then, just end the wizard and start your new virtual host.
getting the error
ERROR: ORA-01034: ORACLE not available ORA-27121: unable to determine size of shared memory segment Linux Error: 13: Permission denied
on a CentOS 5 Oracle box, You can fix it with changing a file permission:
chmod 6751 $ORACLE_HOME/bin/oracle
Dreadful, is’t it? 😉
I’ve just beginned the test of ASSP (Anti Spam SMTP Proxy) in a 1000 mailboxes organization.
I’ve set up a very small Ubuntu server on a virtual vmware host (512 Mbytes of RAM, 1 processor, 10 Gbytes of disk), and then I’ve followed the quick installation steps.
In a few minutes I was able to move all incoming mail traffic into my new SMTP proxy.
Monitoring the situation in the web interface at 55555 port of the Ubuntu box, it looks all ok.
Log files on the real mail server are showing all is running ok, too.
I’m very happy of this experiment: I found ASSP a good spam fighter, easy to install and configure and with a nice web interface for configuration and monitoring the SMTP traffic.
A simple way to add virus filtering on a mail server running courier-mta.