The Misadventures of Penoi

Setting up a web kiosk system using raspberrypi+raspbian+ratpoison

This instruction assumes that you already installed raspbian on your SD card

Installing required packages

sudo apt-get update
sudo apt-get ratpoison
sudo apt-get chromium
sudo apt-get x11vnc
sudo apt-get install x11-xserver-utils

pi@raspberrypi:~$ grep pi /etc/inittab 
1:2345:respawn:/bin/login -f pi tty1 

/dev/tty1 2>&1

pi@raspberrypi:~$ cat /home/pi/.bash_profile
if [ -z "$DISPLAY" ] && [ $(tty) == /dev/tty1 ]; then
startx
fi

pi@raspberrypi:~$ cat /home/pi/.xinitrc
exec ratpoison

pi@raspberrypi:~$ cat /home/pi/.ratpoisonrc
banish
exec xset s off
exec xset -dpms
exec unclutter -root
exec x11vnc -loop
exec /usr/bin/chromium --kiosk http://www.penoycentral.net

vncviewer raspberrypi.local

# rndc querylog 

# rndc querylog

scp file.rar root@192.168.11.60:/var/tmp/
root@192.168.11.60's password:
bash: scp: command not found
lost connection

To insert characters on the beginning of a line. Example, insert // from line 1 to 10

 :1,10s!^!//! 

~/workspace/puppetworks $ cat site.pp
node 'chrisp.lab.local' {#{{{




}#}}}

+--  6 lines: node 'chrisp.lab.local' {#----------------------------------------------------------------------------

Under /etc/rsyslog.conf append

$FileCreateMode 0655
$DirCreateMode 0755
$Umask 0022

$template default,"/srv/logs/%HOSTNAME%/%$now%.log"
*.* ?default

Vmware apologizes for technical difficulties on the recent webcast Technology Day Online. It looks like the webcast provider was caught off guard on the situation. To compensate, VMware will be sending me a USB memory stick containing all of the materials presented on the said event.

Well.. apology accepted!!!!! :)

Our Samsung LCD TV retired after exactly 3 yrs of service. Bad thing is that it is already out of warranty. Yesterday the screen suddenly turns to white that you can barely see the images.

Find and replace string recursively

find /home/penoycentral/whichfolder -type f -print0| xargs -0 sed -i 's/oldstring/newstring/g'

find /home/penoycentral/whichfolder -type f -print0| xargs -0 grep -i oldstring

 sed -n 's/\/etc\/bind/\/var\/named\/master/p' named.conf 

 sed -i 's/\/etc\/bind/\/var\/named\/masterr/g' named.conf 

sed -i "s/[\"]/\'/g" some-file.pp

DNS change progation is one of sysads problem. After a dns record change, nslookup result will differ depending on which region you are in.

Check your DNS global progation

 http://www.whatsmydns.net/

Note this setup is unsecured and just for the purpose of having my own lab svn repo.

Install mercurial on your server

yum install mercurial

mkdir /var/www/cgi-hg
cp /usr/share/doc/mercurial-1.4/hgwebdir.cgi /var/www/cgi-hg/
chmod +x /var/www/cgi-hg/hgwebdir.cgi

 /var/www/cgi-hg/hgweb.config
[paths]
#VIRTUAL_PATH = /REAL/PATH
#myproject = myproject
lab = /srv/hg

service httpd reload

/srv/hg/.hg/hgrc

[web]
allow_push = *
push_ssl = false

Devops Singapore Meetup Puppet in production session

eth0 - with internet connection as they say
eth2 - local network

echo 1 > /proc/sys/net/ipv4/ip_forward 
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A FORWARD -i eth2 -j ACCEPT

penoy@fedora:~$ mail -s "test sending mail from nix server" penoy@example.com < /dev/null

sysctl net.ipv4.ip_forward=1
iptables -t nat -A PREROUTING -p tcp --dport 3129 -j DNAT --to-destination ip-address:3128
iptables -t nat -A POSTROUTING -j MASQUERADE
iptables -L
iptables -t nat -L -n -v
iptables-save

Here's an example of a simple manifest file that will install a package (ex. apache) and will ensure that that the service was started after install

package {'httpd':
   ensure => installed,
    source => '/var/tmp/httpd-2.2.3-53.el5.centos.i386.rpm',
}

service {'httpd':
   ensure     => running,
   enable     => true,
   hasstatus  => true,
   hasrestart => true,
}

[root@learn tmp]# puppet apply httpd.install.pp
err: /Stage[main]//Service[httpd]/ensure: change from stopped to running failed: Could not start Service[httpd]: Execution of '/sbin/service httpd start' returned 1:  at /var/tmp/httpd.install.pp:11
notice: /Stage[main]//Package[httpd]/ensure: created
notice: Finished catalog run in 31.04 seconds

package { 'httpd':
ensure => installed,
source => '/var/tmp/httpd-2.2.3-53.el5.centos.i386.rpm',
}

service { 'httpd':
require => Package['httpd'],
ensure => running,
enable => true,
hasstatus => true,
hasrestart => true,
}

[root@learn tmp]# puppet apply httpd.install.pp
notice: /Stage[main]//Package[httpd]/ensure: created
notice: /Stage[main]//Service[httpd]/ensure: ensure changed 'stopped' to 'running'
notice: Finished catalog run in 34.10 seconds

[root@learn tmp]# chkconfig --list |grep httpd
httpd           0:off   1:off   2:on    3:on    4:on    5:on    6:off
pe-httpd        0:off   1:off   2:on    3:on    4:on    5:on    6:off

[root@learn tmp]# rpm -qa |grep httpd
pe-httpd-2.2.3-17.pe.el5
pe-httpd-passenger-2.2.11-11.pe.el5
httpd-2.2.3-63.el5.centos.1
[root@learn tmp]# service httpd status
httpd (pid  15355) is running...

This is one way of changing your server timezone and resync on the ntp server

 service ntpd stop

 cp /usr/share/zoneinfo/Asia/Singapore /etc/localtime

 ntpdate 

 service ntpd start 

Normally after a server rebuild you will receive a warning that the host identification has changed

 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.

ssh-keygen -f "/home/chris/.ssh/known_hosts" -R ip-address-of-the-host

My mysql database crashed after saving a snapshot thru KVM. Restarting mysqld shows errors under /var/log/mysqld.log

..check that your my.cnf matches the ibdata files..

 mkdir /srv/mysql/old
mv /srv/mysql/ib* /srv/mysql/old
service mysqld restart

To install with prompt

virt-install --prompt

virsh list

virsh destroy 

virsh autostart 

virsh autostart --disable 

virt-install --name=rhel03.localdomain -r 768 --disk path=/var/lib/libvirt/images/rhel03.localdomain.img,size=8 -l http://192.168.122.1/pub/inst -x "ks=http://192.168.122.1/pub/ks/rhel03.cfg"

virsh save centos01 centos01.snap.$(date +%y%m%d)

virsh shutdown centos01
virsh restore centos01.snap

virt-clone --original centos01 --name centos02 --file /home/penoycentral/images/centos02.img

error restoring domain unable to read from monitor

virsh managedsave-remove domain-name

Set mysql root password

mysqladmin -u root password 'new-password'

mysql> show databases;
mysql> use databasename;

mysql> show tables;

mysql> select column from tables;

$mysqldump -u  -p  > backupdatabase.sql

mysql -u  -p  < databasebackup.sql

Im a big fan of Michael Jang. Having seen this upcoming book will greatly help all RHCSA/RHCE aspirants. Hopefully Michael can give me a free copy :)

http://www.amazon.com/RHCSA-Certification-Practice-Virtual-Machines/dp/007180160X/ref=sr_1_4?s=books&ie=UTF8&qid=1335154380&sr=1-4

where is vmnetcfg in VMware Player running in Fedora 16?

It is found under:

/usr/lib/vmware/bin/vmware-netcfg

I will be sitting for Netapp Accelerated NCDA bootcamp Ontap 8.0.7-Mode next week. It will be delivered by Fastlane Singapore, one of the authorized Netapp learning Centers. Hopefully this vendor training will help me to fastrack since my company deploys Netapp storage solutions to our clients.

Will post some reviews next week (if again i have the time :) )

From the destination:(most of the commands done on the destination filer)

Initialize:

snapmirror initialize -S <source-qtree> <destination-qtree>
filer2> snapmirror initialize -S filer1:/vol/vol2/qtree-name filer2:/vol/vol0/qtree-name

> snapmirror status

>snapmirror quiesce <qtree>
filer2> snapmirror quiesce /vol/vol0/qtree-name

>snapmirror resume <destination-path>
filer2> snapmirror resume /vol/vol0/qtree-name

filer2> snapmirror quiesce /vol/vol0/qtree-name
filer2> snapmirror break /vol/vol0/qtree-name

>qtree status

filer2> snapmirror resync -S filer1:/vol/vol2/qtree-name filer2:/vol/vol0/qtree-name

Resized tmpfs space in /etc/fstab to 4g

tmpfs /dev/shm tmpfs size=4096m 0 0

[root@OEL1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oel1-lv_root
16G 3.8G 11G 27% /
tmpfs 2.0G 0 2.0G 0% /dev/shm
/dev/sda1 485M 51M 409M 12% /boot

[root@OEL1 ~]# mount -o remount /dev/shm
[root@OEL1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oel1-lv_root
16G 3.8G 11G 27% /
tmpfs 4.0G 0 4.0G 0% /dev/shm
/dev/sda1 485M 51M 409M 12% /boot
[root@OEL1 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.2 (Santiago)

Will be in Sydney next week for my company induction and training for two weeks. There's a lot of things to learn. One thing that i like with my current employer is that they use Open Source technologies. Not unlike in the Financial industry that almost is proprietary.
Hopefully everything will fall into places.

Got this error when booting up my Virtual Machine in KVM

error restoring domain unable to read from monitor

virsh managedsave-remove domain-name

Fedora 16 Gnome3 gnome-extensions with cairo-dock OpenGL enabled

CNY at the office. kung hei fat choi!!!