Danny Tsang » Linux

Kick A Linux User Who’s Logged In

Danny — Tue, 31 Aug 2010 23:01:28 +0000

In command line type in who or w will list all the users who are currently logged in.

To log them off type in the following:
pkill -KILL -u danny

where danny is the username. If ‘danny’ was logged in multiple times e.g locally and via ssh then both will be logged off.

Linux logout user or logoff user commands

Change Default Crontab Editor

Danny — Thu, 26 Aug 2010 07:53:35 +0000

To change the default crontab editor type in the following command:
export EDITOR=nano
Change nano for your preferred editor.

Crontab editor

Tethering HTC Desire With Ubuntu 9.10

Danny — Sun, 01 Aug 2010 08:47:30 +0000

I read that Ubuntu 10.04 detected the HTC Desire automatically so I tried it on my EEE PC running Ubuntu 9.10.

Plugged the USB cable in, set it to Internet Mode. a few seconds later Ubuntu reported it was connected.

Tether a HTC Desire with Ubuntu 10.04 (Lucid) via USB

Show Nautilus As Text In Ubuntu 10.04

Danny — Sat, 17 Jul 2010 08:57:06 +0000

In the new Ubuntu the windows manager Nautilus does not change from an icon to a text when you click on the current directory in the bread crumb. To solve this use the shortcut Ctrl + L

VNC/RDP Not Refreshing On Ubuntu

Danny — Sun, 27 Jun 2010 09:59:24 +0000

When I use VNC Client to remote desktop onto my Ubuntu 10.04 I got the background and maybe even the Gnome panel but the windows and programs were not appearing on the screen. However my mouse and clipboard was still working so I had ended up VNC’ing to the box and switching the display to another source.

To fix this problem just disable the visual desktop effects under System > Preferences > Appearance Under the Visual Effects tab set it to None.

VNC – remote desktop does not refresh

Linksys SPA3102 And FreePBX On Ubuntu 10.04

Danny — Thu, 10 Jun 2010 23:01:47 +0000

Overview

I wanted to setup a Private Branch eXchange(PBX) system using Asterisk server at home. As I already had a traditional land line (PSTN or POTS line) I needed something to bridge the computer to the land line. My idea of having a PBX at was to route as many calls over VOIP which tends to be cheaper like Skype and still use a traditional landline for emergencies as well as just having a landline number.

History

Originally I started writing a post on how to get a PBX with a web interface going on Ubuntu 8.04. However once I had it all installed it wasn’t working 100%. I had issues with permissions and FreePBX had problems with the operation panel. Fast forward 2-3 years and I’m back doing it again but this time on the next LTS release and 7 minor release later from FreePBX.

Ubuntu 10.04 LTS

Asterisk

Asterisk is a free and open source software for PBX. It’s what you see in companies to manage and route all their phones calls. Asterisk is a PBX engine which has several front end engines and even a distribution specially for PBX box called Trixbox. If you just want a headless PBX then installing Asterix will suffice however I was not technically skilled enough to create all configuration files from scratch and also a nice front end will go a long way for the Wife Acceptance Factor (WAF). This is where FreePBX comes in.

FreePBX

FreePBX is GUI interface wrapper for Asterisk. Ubuntu has a FreePBX package in it’s repository. FreePBX uses a web front end so it can be accessed anywhere and makes administration a lot easier. It uses modules to extend the functionally like add-ons in Firefox. These include group pickup to Parking Lots.

With FreePBX this sorts out the software side of my PBX.

Linksys SPA3102

This an Analogue Telephone Adaptor(ATA) which is used to convert a land line to a digital network and a traditional land line phone to the network too. The hardware has been around for a long time and it does work with Asterisk. The SPA(Sipura)3102 can be used as a standalone PBX box too but in my case it will be used to forward incoming and outgoing calls.

The SPA3102 also has a web interface but it can also be used to act as a router at the same time. The web interface is very basic and not very user friendly but has a lot of options making it very customizable and configurable.

Asterisk And FreePBX Install

Switch to root user before installing sudo su.

Install MySQL sudo apt-get install mysql-server
When prompted for password enter one.

Install MySQL modules, PHP, kernel headers for compiling code, apt-get install build-essential linux-headers-`uname -r` openssh-server bison flex apache2 php5 php5-curl php5-cli php5-mysql php-pear php-db php5-gd curl sox libncurses5-dev libssl-dev libmysqlclient15-dev mpg123 libxml2-dev

Go to /usr/src cd /usr/src/
and download the Asterisk source files

xargs wget << SOURCES

http://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/releases/dahdi-linux-complete-2.2.1+2.2.1.tar.gz

http://downloads.asterisk.org/pub/telephony/libpri/releases/libpri-1.4.10.2.tar.gz

http://downloads.asterisk.org/pub/telephony/asterisk/releases/asterisk-1.6.2.6.tar.gz

http://downloads.asterisk.org/pub/telephony/asterisk/releases/asterisk-addons-1.6.2.0.tar.gz

SOURCES

Un-tar(zip) all the source files in /usr/src/ tar xvf dahdi-linux-complete-2.2.1+2.2.1.tar.gz
tar xvf libpri-1.4.10.2.tar.gz
tar xvf asterisk-1.6.2.6.tar.gz
tar xvf asterisk-addons-1.6.2.0.tar.gz

Compile Asterisk in the following order:
cd dahdi-linux-complete-2.2.1+2.2.1
make all && make install && make config
cd ../libpri-1.4.10.2
make && make install
cd ../asterisk-1.6.2.6
./configure
make && make install
make samples
cd ../asterisk-addons-1.6.2.0
./configure
make && make install
make samples
Download and extract extra sounds cd /var/lib/astersik/sounds
wget -O - http://downloads.asterisk.org/pub/telephony/sounds/asterisk-extra-sounds-en-gsm-current.tar.gz | tar xvfz -

Create an Asterisk user account on the Linux box adduser asterisk --disabled-password --no-create-home --gecos "asterisk PBX user"
adduser www-data asterisk

Make a backup of the Asterisk configuration file cp /etc/apache2/apache2.conf /etc/apache2/apache2.conf_orig

Change the Asterisk config to run as a correct user sed -i 's/^$User\|Group$.*/\1 asterisk/' /etc/apache2/apache2.conf

Create the Asterisk service script which will start and stop the Asterisk demon:

cat > /etc/init.d/asterisk <<-END_STARTUP
#!/bin/bash
### BEGIN INIT INFO
# Provides: asterisk
# Required-Start: \$network \$syslog
# Required-Stop: \$network \$syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Asterisk daemon.
# Description: This script handles start/stop states of asterisk.
### END INIT INFO

set -e
set -a
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DESC="Asterisk"
NAME=amportal
DAEMON=/usr/sbin/\$NAME

test -x \$DAEMON || exit 0

d_start() {
amportal start
}

d_stop() {
amportal stop
}

d_reload() {
amportal restart
}

case "\$1" in

start)
echo -n "Starting \$DESC: \$NAME"
d_start
echo "."
;;

stop)
echo -n "Stopping \$DESC: \$NAME"
d_stop
echo "."
;;

restart|force-reload)
echo -n "Restarting \$DESC: \$NAME"
d_stop
sleep 10
d_start
echo "."
;;

*)

echo "Usage: \$SCRIPTNAME {start|stop|restart|force-reload}" >&2
exit 3
;;

esac

exit 0
END_STARTUP

Ensure the permissions of the demon script is correct chmod 755 /etc/init.d/asterisk

Make Asterisk start up when the computer starts update-rc.d asterisk defaults 90 10

Download and extract FreePBX
cd /usr/src/
wget -O - http://mirror.freepbx.org/freepbx-2.7.0.tar.gz | tar xvfz -
cd freepbx-2.7.0/

Copy the Amportal configuration cp amportal.conf /etc/

Set environment variables for the current session. These variables will store the password for MySQL access so that the script can be 100% automated. One is the admin password and the other is the Asterisk database user password. These variables should clear once the terminal session ends but it is advised to remove them from the bash history in ~/.bash_history
export MYSQL_ROOT_PW=abcd
export ASTERISK_DB_PW=wxyz

Run the database scripts:
mysqladmin -u root -p${MYSQL_ROOT_PW} create asterisk
mysqladmin -u root -p${MYSQL_ROOT_PW} create asteriskcdrdb
mysql -u root -p${MYSQL_ROOT_PW} asterisk < SQL/newinstall.sql
mysql -u root -p${MYSQL_ROOT_PW} asteriskcdrdb < SQL/cdr_mysql_table.sql

mysql -u root -p${MYSQL_ROOT_PW} <<-END_PRIVS
GRANT ALL PRIVILEGES ON asterisk.* TO asteriskuser@localhost IDENTIFIED BY "${ASTERISK_DB_PW}";
GRANT ALL PRIVILEGES ON asteriskcdrdb.* TO asteriskuser@localhost IDENTIFIED BY "${ASTERISK_DB_PW}";
flush privileges;
END_PRIVS

Edit the amportal configuration file with the database username and password
sed -i "s/# $AMPDBUSER=.*$/\1/" /etc/amportal.conf
sed -i "s/# $AMPDBPASS=$.*/\1${ASTERISK_DB_PW}/" /etc/amportal.conf
sed -i "s@$AMPWEBROOT=$.*@\1/var/www/@" /etc/amportal.conf
sed -i "s@$FOPWEBROOT=$.*@\1/var/www/panel@" /etc/amportal.conf
sed -i "s@$FOPWEBADDRESS=$.*@PUTIPADDRESS@" /etc/amportal.conf

Change the max PHP file upload size to 120mb in Apache
sed -i 's/$^upload_max_filesize = $.*/\120M/' /etc/php5/apache2/php.ini

Change the files and directories so that Asterisk has access to them
chown asterisk. /var/run/asterisk
chown -R asterisk. /etc/asterisk
chown -R asterisk. /var/{lib,log,spool}/asterisk
chown -R asterisk. /var/www/

Remove line ending from the Asterisk configuration file.
sed -i '1 s/$\[directories\]$.*/\1/' /etc/asterisk/asterisk.conf

Start Asterisk
./start_asterisk start

Install FreePBX
./install_amp

Restart Apache server
/etc/init.d/apache2 restart

Create a symlink to the "Music On Hold"(MOH) files
ln -s /var/lib/asterisk/moh /var/lib/asterisk/mohmp3

Start FreePBX
amportal start

Asterisk / PBX Terminology

Before I go into configuring the PBX itself it is worth knowing the terminology behind the technology.

Extension - Can be considered as an internal phone number. Each extension can be associated with a user and the user and the user can "roam" from phone to phone keeping their phone number.
Feature Codes - Special phone numbers which can put an extension to do not disturb (DND) so that no phone calls will get through to accessing voicemail.
Trunk - Provides services to the PBX such as land line or to allow calls to another PBX.
Routes - The path a call may go. Routes consists of inbound, calls coming in and outbound, calls leaving the system routes.
Dial Rules - Rules defined in ASCII characters which govern routes e.g Only free phone numbers are allowed to take the land line route. All other numbers should go out to a VOIP provider.
Channels - Number of simultaneous calls a trunk can handle

Configure FreePBX

First thing to do is set up extensions. Extensions are independent to any available routes as by default Asterisk treats any number dialled as an internal number. Below are steps to create 2 extensions. One number will eventually be assigned to the phone attached to the Linksys SPA3102 and the other for another hard/softphone.

Go to Setup > Basic > Extensions menu item.
Ensure "Generic SIP Device" is selected in the Devices drop down box.
Enter the following details:

User Extension - Phone number of extension E.G 1000
Display Name - Friendly name
Voicemail & Directory Status - Enable this if you want the user to have voicemail facilities
Secret - Leave blank for now but this is the password for the extension.

Submit the changes.
Click on the new extension listed on the right hand side of the Extensions page. This will edit the extension
Under Device Options section change the Mailbox by removing the @device suffix and just leave the extension number in the field.
Submit the changes again.
Repeat the steps above again to create a second extension, changing the extension number, display name and the mailbox setting E.G 1001
Apply the changes to make it take effect.

At this point I would download a SIP softphone such as X-Lite on two computers and test out the 2 extensions created. Using the X-Lite or other softphones is beyond this article.

For Dialling out of the Sipura 3102 a Trunk is needed as well as configuring the outbound route.

Go to Setup > Basic > Trunks in FreePBX
Click on the Add SIP Trunk
Fill in the following fields:

Trunk Description - A friendly name for the trunk. This can be anything
Outbound Caller ID - Full telephone number of the landline including area code.
CID Options - Any
Maximum Channels - 1
Dial Rules - Leave blank
Outbound Dial Prefix - Leave blank
Trunk Name - A memorable name which will be used in the Sipura configuration
Peer Details:

canreinvite=no
context=from-pstn
host=[host]
nat=no
port=5061
type=friend
qualify=yes
dtmfmode=rfc2833

Change [host] to the IP address of computer hosting Asterisk / FreePBX and [username] to username to be used by Sipura
Leave the remaining fields blank.

Submit Changes.
Go to Setup > Basic > Outbound Routes
Click on 0 9_outside (or create a new one)
Change the settings to as follows:

All fields should be blank or left as default up to Dial Patterns.
Dial Patterns - 9|.
Trunk Sequence - Select the Trunk created above.

Submit changes.
Apply the changes.

The above setting outbound route requires a 9 to be dialled followed by the number to be dialled. The dial pattern can be changed later.

Create a new inbound route for the landline to Asterisk via SPA3102:

Go to Setup > Inbound Call Control > Inbound Routes
Change the following settings:

Description - A meaningful name for the inbound route
DID Number - Enter the landline telephone number including the area code.
Set Destination - Set where the landline call should go to. This can be voicemail or an extension

Submit changes.
Apply Settings

It is worth mentioning here that there is a module in FreePBX called Ring Group which would allow a group of extensions to be named as a destination. This means anyone in the group will have their phone ring when someone rings the landline.

As a recommended step check if a password has been set on the admin web page. Clear out the browser's cookies and cache. Go to the Freepbx page and click on the FreePBX Administration link it should prompt for a password. If not edit the default admin account or add a new account under Setup > Basic > Administration

Notice there is a warning under "General Settings". This means the authentication has not been turned on. Submit the changes and apply them once completed. Go to the Freepbx box and edit the file /etc/amportal.conf Look for the line AUTHTYPE=none and change it from none to database.

Setting Up SPA3102

Out of the box the ATA is configured to act as a router and has the web interface disabled on the WAN port. I will be putting SPA3102 into an existing network so I need to enable the WAN port and turn off the DHCP. The WAN port needs to be enabled so that it can connect to the local network instead of the box expecting a modem and turning off DHCP will stop two devices assigning an IP to the computers on the network.

Plug a telephone into phone socket of the SPA3102 and the power in the power socket. Pick up the phone and dial ***** (5 asterisks) and then 7932 and then 1. Hang up or press #.

Now plug the network cable into the Internet port of the SPA3102 NOT THE ETHERNET PORT. Point your browser to the IP address of the SPA3102. To find out what the IP is you should be able to check on your router or dial ***** (5 asterisks) > 110 on your phone.

Just like a router, a webpage with settings and status of the device should appear. Use the screenshots below and set all the settings below:

The settings are for UK and I have change the tones in the Voice > Regional settings. Others such as the daylight savings are aligned to the UK time zone.

The following needs to be configured according to the environment.
Voice > Line 1 > Proxy and Registration

Proxy - IP address of the Linux box which will host the Asterisk and FreePBX software.

Voice > Line 1 > Subscriber Information

User ID - Extension set in FreePBX
Password - Leave blank initially for easier debugging but it should match the secret settings in the extensions

Voice > PSTN Line > Proxy and Registration

Proxy - IP address of the Linux box which will host the Asterisk and FreePBX software.

Voice > PSTN Line > Dial Plans

Dial Plan 2 - S0(<:xxxxxxxxxx>) where x is the phone number of your land land including the area code e.g 01323123456

Asterisk
Trixbox
FreePBX
Installing Asterisk and FreePBX on a vmware instance of Ubuntu 10.04 (Lucid) alpha3

Full Disk – MediaTomb Hog

Danny — Sun, 30 May 2010 21:40:46 +0000

For some reason MediaTomb was out putting a lot of log statements in /var/log/mediatomb.log. I tailed the file and only got what looked like time stamped entries of normal scanning information as I have timed re-scans.

The file managed to fill my 250GB hard drive when Ubuntu 10.04 started to complain. After removing the file using the command line all was fine again.

HTC Desire Mini Review

Danny — Thu, 29 Apr 2010 23:01:43 +0000

Overview

I have finally made the jump from the iPhone to an Android OS phone. Whilst the OS 4.0 from Apple preview event looked good, there was no sign or mention that they will change the App store and it’s draconian approval process.

HTC vs. Google

I was undecided between the HTC Desire and the Google Nexus One. There two phones run on a similar platform but there are subtle differences such as noise cancellation and track ball on the Nexus vs. Sense UI and an optical track (ball).

The decision was made to go the Desire because:

It was out in the UK before the Nexus
Proper physical buttons instead of the touch sensitive buttons

Unboxing

The phone came in a very small package but still managed to fit most of the items I’d expected to see to come with the phone e.g earphones, documents, etc.

I do have to say there was no manual that came with the phone but it was more like a quick start guide. On the first start up of the phone there was another quick introduction but nothing substantial for those who like to read the manual.

Replacing iPhone

After having an Apple iPhone 3G for just over 18 months it was apparent what I missed and what I loved about the new phone.

Pros:

No download limit – Previously there was a 10mb download limit from the App store or iTunes over the mobile carrier. With Android there is no such limit.
Removable battery – Not that I plan to change the battery often but it’s nice to know I can.
Auto focus camera – It bugged me that the iPhone camera did not have macro mode but the HTC Desire even has face recognition.
Micro USB – A standard connector so I do not have to hunt for an Apple specific one to power the device
USB mode – Ability to set the mode when it is connected to the computer e.g charge, Sync, Tether…
Tethering – Ability to tether via USB out of the box (except for the need to download the USB drive in Windows)
Multitasking – The ability to run multiple threads at a time in the background has it’s pros and cons. For the good parts it’s been everything the iPhone should have done with the push notification. I was getting RSS to update at regular intervals so when I open the app it had them already cached, sending tweets can be done with the app closed so you are free to do other things once the send button is pressed and even Facebook allowed uploading of pictures in another thread!

Cons:

Headphone profile – Connecting a headphone/earphone to the 3.5mm jack does not change the volume to what it was set to before when a jack was connected.
Battery life – I was able to make it through the whole day usually without the iPhone running out of power but the Desire does if I play any games for a long period.
Lack of Apps – Particular high quality games such as Popcap games. There are some good apps but nothing near the amount the iPhone has.
Multitasking – Apple was correct when they said it would use more power if they enabled multitasking and with the HTC Desire I saw the side effects. This had lead to reducing the amount of background updates and notifications as well as killing some of the other watchdog threads in Twitter and Facebook clients.
~~Conference calls – There’s no option to allow more one or more people to an existing call.~~

The phone does have conference calling function but it is not displayed on screen during a call. Pressing the menu button reveals this function

Observations:

Apps are smaller – Android apps seems to be smaller but that may be because the iPhone Apps may use more custom graphics.
Headphone jack detection – Whilst connecting a headset does not lower the volume on the Android device, it still stops the music play back if the jack is removed from the port.
Case – Whilst both the Apple iPhone and the HTC Desire did not come with a case it would have been a nice touch like the HTC HD2.

Personal Preference

I still prefer the Apple iPhone’s keyboard but that may be because I was use to using it the Apple way. The typing of the keys felt slightly less accurate but I’m getting better at it and the spelling corrections are not as well done but the words in the dictionary are much better because it contains some odd words not in the dictionary.

HTC Sense UI does add some good integration from third party companies such as Facebook and Twitter integration to the contacts. The “People” or contacts page allows for linking and unlinking from Facebook profiles. Once linked it will associate people’s profile pictures to the contact on the phone.

There are caveats to this like some profile pictures have really low resolution so it gets blown up on screen when the person calls and also HTC has duplicated some of the functionalities the Android OS provides already for this integration. For example HTC has it’s own version of Facebook application which allows it to link to the peoples page but the non HTC Facebook app also has to be installed in order for it to work. This means there are two apps which appear in the programs list for Facebook.

Summary

I am happy with the trade offs for the phone but I hope the continous improvements made by both Google and HTC will come to fix some of the issues I have raised over time.

In terms of the battery problem I do not think there is anything that can be done without a re-design.

PDF Printer In Ubuntu

Danny — Mon, 01 Mar 2010 00:01:49 +0000

It is really simple to add a PDF printer in Ubuntu 9.10. A PDF printer prints a page and writes to a file in PDF format. To install this feature typer in the terminal:
sudo apt-get install cups-pdf

That’s it. It should install and even add the printer automatically.

Mount ISO File In Linux

Danny — Sat, 13 Feb 2010 01:03:30 +0000

A neat trick in Linux is the ability to mount an .iso file as if it was a CDROM.

The command to do this is:
sudo mount -t iso9660 -o loop /home/danny/filename.iso /media/cdrom

where “/home/danny/filename.iso” is the path to the ISO file and the latter “/media/cdrom” is the mount point. In this case it will mount it where the CDROM would normally be mounted on.

Mount ISO as CD-rom not as a folder

NFS Server

Danny — Fri, 12 Feb 2010 10:40:32 +0000

Overview

Network File Share (NFS) is a protocol for sharing storage. It is quite common in Network Attached Storage (NAS) devices and is a standard compared to Samba which is Microsoft specific but has been ported to Linux.

Install NFS Server

Install the relevant software:
sudo apt-get install nfs-kernel-server nfs-common portmap

Configure NFS Server

Configuring NFS server is relatively simply. Edit the file /etc/exports file and add all the directories available as a share. The format should be as follows

/media/cdrom 192.168.0.1/24(rw,async)

mount point on local system.

host

permissions

Using the above string this would share the CDROM to any computer with the IP range 192.168.0.1-192.168.0.254 that has read and write permissions and requests can be process asynchronously.

Specific IPs can be given to each share like this:

/media/cdrom 192.168.0.1(rw,async) 192.168.0.1(ro,async)

Computer 192.168.0.1 has the permissions described in the above example and the computer with 192.168.0.2 only has asynchronous requests and read only access to files for that share.

When specifying mount points note where the spaces are and are not because spaces are read by the system so

/media/cdrom 192.168.0.1 (rw,async)

is invalid because there is a space between the IP address and the parenthesis.

Once all the shares have been configured it is necessary to restart NFS to see the changes:
sudo /etc/init.d/nfs-kernel-server restart

Mount NFS Share On Linux

Install the NFS client if the computer does not have a NFS server itself:
sudo apt-get install portmap nfs-common

To mount the share manually from the terminal type the following:
sudo mount 192.168.0.1:/media/cdrom /media/share
First is super user command sudo then mount command, IP address of NFS server followed by the path to share. The last parameter is the local mount point so in the above example it will mount the CDROM drive from the server onto /media/share directory of the client computer.

To make the mount more permanent edit the /etc/fstab file and the following line, one for each NFS share.

192.168.0.1:/media/cdrom /media/share nfs rsize=8192,wsize=8192,timeo=14,intr

The only part that needs to be changed is the IP address, NFS share point and the mount point. This is highlighted in bold in the example above. The rest should be fine left as is. This change should mount the share when the computer is started.

Mount NFS Share On Windows 7 Ultimate Edition

NFS support does not come as standard with Windows so it has to be installed. Also I only found the feature in Windows 7 Ultimate Edition and not the Professional. I believe there is a Business Edition in between but do not know if it has the support for NFS.

Go to the Control Panel and on the left hand side click on Turn Windows features on or off hyper link. It will load a list of software in a tree / node structure. Find Services for NFS and tick Client for NFS as a minimum.

On the start menu right click on Network and select Map network drive. If this option is not in the start menu go to Computer and right click on Network from the left hand panel. A wizard will start for mapping a network drive.

Select the drive letter to be assigned to the NFS share and for the Folder enter the address [server]:[path] for example 192.168.0.1:/media/cdrom
Tick Reconnect at logon if you want it to connect on start up and click Finish to end the wizard.

The only problem with mounting the NFS on Windows is every time Computer it takes a longer to scan and load the drives because it scans the NFS to get the size and amount used on the NFS.

Summary

NFS between Linux machines is perfect and a good way to share files. Mounting a NFS makes the local share look as if it was it was local drive.

For Windows I’d stick to using Samba because it doesn’t take a while to scan the shared drive every time the drive is highlighted to get the drive information such as amount of space available. It’s not a nice to administer two services doing the same thing but it works.

NFS Server and Client Configuration in Ubuntu

MediaTomb DLNA To Playstation 3

Danny — Mon, 08 Feb 2010 00:01:19 +0000

Overview

I found the Video plugin for MythTV 0.21 to be inadequate for streaming to the Sony Playstation 3. It didn’t update fast enough when you dropped a video into the UPnP directory and also there was no external way of telling it to refresh it’s list of files without starting up Myth Frontend.

MediaTomb

MediaTomb is a UPnP server which can run as a standalone or as a daemon. It uses an XML configuration file for it’s settings (pretty neat stuff) and is pretty small in size. The software comes with it’s own web server so you don’t have to install a full apache install to get to the control panel and it uses SQLite by default so no big database backend to be installed.

Install & Configure MediaTomb

Install MediaTomb and ffmeg thumbnailer
sudo apt-get install mediatomb ffmpegthumbnailer
That’s it for the install!

edit the file config file in /etc/mediatomb/config.xml and change the following settings:

Enable PS3 support change this:

and also

–>

Add the line

below
/usr/share/mediatomb/web
so that it looks like this
/usr/share/mediatomb/web
This hides the full directory path from the Playstation so it can only view the directories added and not the full system.

Add the following to enable thumbnail previews. I have found this does not work 100% of the time.

Enable transcoding

to

Add the following transcode mappings under tag:

Add the following settings between the elements. Not the parent is plural and each profile is singular.

image/jpeg
yes
yes
128×128

Restart MediaTomb service sudo /etc/init.d/mediatomb restart If it fails to restart then double check the config file for errors.

Go to the machine in a web browser on port 49152 e.g http://localhost:49152

On this web page configures the directories available over UPnP. The Database section shows what directories are visible / registered to MediaTomb and Filesystem shows the computer directories that can be added for DLNA / UPnP visibility. When a directory is added MediaTomb scans the directory and register them so they show up on the Playstation. These can include music, videos and pictures.

In the top right hand corner there is a plus “+” with two arrows around it. Clicking on it loads a new page in the main window, replacing the file lists in the directory. This is the page for setting how often it scans for changes.

Go to the Playstation, turn it on and go to the relevant category e.g photo in the menu. There should be a MediaTomb server in the list. If it does not appear go towards the top and scan for more media servers to look for MediaTomb.

Summary

The software is pretty self contained but I would have liked the option to use Apache and MySQL because those are already installed on my system.

MediaTomb does the job for now and whilst I cannot get the thumbnails to work on all the media it still does a brillant job of streaming the media to the Playstation. Unfortunately it’s not integrated into MythTV so records will still have to be done via MythTV but this is not a problem because all recorded TV shows are registered in the database.

A problem I did encounter was that I added multiple directories but reguardless of where they reside on the computer, all videos appear in one directory on the Playstation. I’m not sure if this is a bug or how it’s suppose to work.

[HOWTO]:Stream DivX/XviD to a PS3 with firmware 2.10 using MediaTomb and Ubuntu 7

Enable SFTP On VSFTPD In Ubuntu

Danny — Sun, 31 Jan 2010 00:01:41 +0000

Enabling SFTP is very easy and makes FTP protocol a lot more secure than traditional FTP because passwords are not sent in plain text which is susceptible to a lot of things such as packet sniffers, man-in-the-middle, etc.

Assuming VSFTPD has been installed (in the default location) edit the file /etc/vsftpd.conf and check there are security certificates installed and configured.

There are two entries which start with either:
dsa_cert_file dsa_private_key_file
or
rsa_cert_file rsa_private_key_file
Each specifying a file path to where the key and certificates are located.

The last step is to enable SFTP by adding the following line:
ssl_enable=YES
Save and exit the file and restart the FTP server sudo /etc/init.d/vsftpd restart

Bypass Blocked Websites Using SSH Proxy

Danny — Tue, 19 Jan 2010 00:01:27 +0000

Overview

SSH tunnels are very useful for all sorts of things. One of these uses include proxy. If you have SSH access you can set one up very quickly.

I do not condone any misuses of any I.T equipment, software or any other kind described in this article. All practices should be used within the law and policy set by your region. Any examples are given are done so to highlight the uses this article may provide.

Uses

By using your own SSH proxy you can by pass firewalls or blocked websites by directing the data through this connection and out from your SSH server.

For example at a work place they block websites such as Facebook, Twitter, etc. As long as you can connect to your SSH server the web traffic can be re-routed through this connection without the company seeing what is happening when the data is being re-routed apart from you have a SSH session (which may raise some eye brows if you do not have a legitimate use in your daily activities).

Pre-requisites

A server running an SSH server. The remainder of this article will be done on a Ubuntu box.

Install SSH server by entering the following command in the terminal:
$ sudo apt-get install openssh-server

The default configuration should suffice and you can use your local accounts to log in.

Establishing Multiple Ports

It is generally a good idea to have your SSH server listening to more than just the default port (which is 22). Most places may ban this port to stop SSH session going out of an organization potentially leaving a connection open for unwanted outsiders.

To work around this look at my earlier article on how to set up multiple ports on the SSH server.

Using Proxy On Windows

Download Putty from Putty’s website. It’s just a small program that lets you connect to a SSH server amongst other protocols.

Starting the program up will show a window with a tree like navigation to the left and settings pane to the right and a bunch of buttons at the bottom. The following sections are based on the nodes on the left hand side of the window.

Session

Enter the IP address of the server and the ports configured above. Ensure the Connection type is set to SSH.

In Saved Sessions enter a name to call your connection so you do not have to enter the above and the following details every time. Do not press the Save button till all the settings have been set.

Connection > SSH > Tunnels

Enter the port your web browser will be using in the Source port box.

Leave Destination blank and select Dynamic and Auto radio buttons. Click the Add button to add the connection tunnel to the list. Multiple tunnels can be entered as long as different ports are used.

At this point you can go back to the Session page and save the session by clicking on the Save button. To load the connection next time, select it from the list and click on the Load button.

Click on the Open button to initiate the connection.

A warning my come up if it’s your first time connecting to your server via SSH. Accept it and it will prompt for a username then password. Enter your details pressing enter at each stage to move onto the next.

Once you get in it’s time to configure the web browser.

FireFox

Go to Tools > Options… Select the Advanced button and go to the Network tab. Click on the Settings button in the connection area. A new window should pop up.

Select Manual proxy configuration and set the HTTP Proxy to localhost and the source port set in the Putty section. Ok to all the dialogues and your done.

Internet Explorer

Go to Tools > Internet Options. In Internet Options window go to the Connections tab.

Click on the LAN settings button to reveal another window.

In the Proxy server settings tick the box for Use a proxy server for your LAN… and enter the address as localhost and the port as the source port in Putty. Save and close all dialogue boxes and windows.

Summary

A neat trick to stop people snooping at your browsing habits or just to avoid blocked sites. Sites may load slower because it has to go from your local machine, to the proxy server and out to the Internet and back again.

energy@home Twitter Integration

Danny — Fri, 08 Jan 2010 00:01:06 +0000

A preview of my part time project energy@home with Twitter integration.

As you can see the value for total energy used is currently way off but it’s a preview of what’s to come.

There are two options: tweet hourly summary and daily summary. These can be turned on and off. I am using python-twitter library which does not use oauth authentication so the client description comes up as API which is not nice.

Unable to access MythTV Perl API. Try with –verbose to find out why.

Danny — Mon, 28 Dec 2009 09:28:00 +0000

I have been getting the error message

Unable to access MythTV Perl API. Try with –verbose to find out why.

on MythTv running on Ubuntu 8.04. It wasn’t bothering me too much because the TV guide was still being updated. Also I believe this is something to do with MythTV-Status only which prints out in the console what is being recorded (if any), next up coming recording and the amount of available space.

The problem is the MythTv-Status program is ran on a schedule and is requires the config.xml in the ~/.mythtv directory to be copied or a symbolic link in /root/.mythtv Run the following commands to solve the problem:
$ sudo mkdir /root/.mythtv $ sudo ln -s ~/.mythtv/config.xml $ sudo /etc/init.d/mythtv-status reload

The last command will run MythTv-Status to read the new configuration XML file and run without any errors.

The only problem it has caused is that it does not say how many days worth or TV guide it has where as before this fix it specified it with errors.

Unable to access MythTV Perl API. Try with –verbose to find out why. Ubuntu Forum

SSH On Multiple Ports

Danny — Mon, 14 Dec 2009 00:07:27 +0000

It is possible to have SSHD (SSH server) to listen on multiple ports. some places block port 22 the default port for SSH. To over come this you can use another port such as 3389 (which happens to be the Windows remote desktop port number) which may not be blocked.

In Ubuntu edit the /etc/ssh/sshd_config and add another entry Port 3389 or what ever port number. For convention I’d recommend adding it above or below the default Port 22. Save and exit the text editor and restart the SSH server for the new settings to take effect sudo /etc/init.d/ssh restart.

Remember to configure the router with the new port.

running sshd on 2 ports? Ubuntu forum post

Sync Mozilla Thunderbird Using Dropbox

Danny — Mon, 16 Nov 2009 20:28:30 +0000

Overview

I have had a Dropbox account for a while now but never really used it till now. There have been really good tricks and uses to Dropbox posted on the Internet and I finally decided to try my hands at synchronising my emails.

Dropbox Setup

Install Dropbox and create an account. I am using the free 2GB as my total mail folder size is less than 2GB. Head over to https://www.getdropbox.com and follow the instructions for installing Dropbox. I will assume the Dropbox folder is set to default which is ~\username\My Dropbox in Windows or ~/username/Dropbox in Ubuntu Linux.

Mozilla Thunderbird Setup

I am assuming this already exists. If not go to http://www.mozillamessaging.com/en-US/thunderbird/ and install it.

Sync Setup On Windows

Close down Mozilla Thunderbird program. I would recommend creating a directory for your emails within the Dropbox directory. I named mine Thunderbird e.g C:\Users\username\My Dropbox\Thunderbird

At a minimum the default profile needs to be copied to the Dropbox directory. Copy: C:\Users\username\AppData\Roaming\Thunderbird\Profiles to C:\Users\username\My Dropbox\Thunderbird\Profiles\xxxxxxxx.default

xxxxxxxx.default = a random filename with .default at the end of the folder name.

Other files may be copied under the My Dropbox\Thunderbird directory such as email notification sounds so it is always backed up and sync’d across.

Point Thunderbird to the new location of your profile by starting Thunderbird with the following arguments thunderbird.exe -ProfileManager This can be done by creating / editing a Thunderbird shortcut or Start Menu > Run dialog

Create a new profile and click Next > button on the wizard pop up window. Select Choose Folder… and locate the xxxxxxxx.default directory in My Dropbox directory and press finish.

You may delete the old user or select the new user and click on Start Thunderbird button.

Sync Setup On Ubuntu / Linux

All the steps are the same as Windows setup except for the different file paths and to start the profile manger user mozilla-thunderbird -ProfileManager in the command line.

The default profile directory in Ubuntu is located in /home/username/.thunderbird/xxxxxxxx.default


Summary
It's really easy and now it allows me to user Thunderbird from anywhere so long as the files have been sync'd to Dropbox. I generally take periodic copies of the profile directory in case something terribly goes wrong with the sync.
I have ran into problems using this setup including my Trash file size became larger than the 2GB allowed on my free account. I tried emptying it from within Thunderbird but it failed so I deleted the Trash.msf file and it solved my problems.




Dropbox
Mozilla Thunderbird


Related posts:
Dropbox Causes Duplicate Folders In Mozilla Thunderbird
Thunderbird HTML Signatures
Microsoft FolderShare



Ubuntu 9.10 Grub2 No Timeout
Danny — Sat, 14 Nov 2009 12:11:00 +0000
I have recently upgraded to Ubuntu 9.10 and found that the timeout doesn’t seem to be working.
Grub’s timeout feature allows for automatically boot up into a selected OS after a specified amount of time. By default it’s 10 seconds. For some reason this was not happening for me.
To fix it I install Start Up Manager. To do this run $ sudo apt-get install startupmanager and go to System > Administration > StartUp Manager to get a graphical tool. It lacks a lot of options compared to writing it manually but it’s good enough. Set the timeout time and close the window. It should re-build the Grub settings before completely exiting. Restart and it should work.
Update: There was a Grub2 update between writing this post and publishing it which did change the config of Grub.


Related posts:
Installing Ubuntu 8.10 From USB Stick
VirtualBox With Ubuntu Quick Review
Ubuntu 7.10



Check GUI Program Is Running In Linux
Danny — Mon, 02 Nov 2009 00:01:08 +0000
Overview
I have create a bash script to:

Check if the program’s process is running
If so just quit the script
If not start up the program

Using this script and crontab it allows the script to be ran every x time checking to make sure the program is running.
Setup
Log into the user who will / has permission to run the script as well as the program. I shall use Azureus / Vuze as my example since this was the program I wrote it for. I also assume that you are using the downloaded version and not the one from the repository.
Script
Create an empty file. I shall use $home as in your user directory e.g /home/danny Paste the following script into the file:
#!/bin/bash

PROGRAM=’azureus’
if ps ax | grep -v grep | grep $PROGRAM > /dev/null

then

    echo “$PROGRAM PROGRAM running, everything is fine”

    exit

else

    echo “$PROGRAM is not running”

    echo “Starting $PROGRAM”

    DISPLAY=:0.0 /home/danny/vuze/azureus &>/tmp/azureus.out
    if ps ax | grep -v grep | grep $PROGRAM > /dev/null

    then

        echo “$PROGRAM PROGRAM running, everything is fine”

    else

        echo “Unable to start $PROGRAM”

    fi

fi
myScript
Just to explain the script from top to bottom. If you are not interested skip this paragraph. The first line declares it’s a bash shell script and where bash can be found. PROGRAM is a variable holding the program name this can be changed to any other program. The if statement does a “ps” command which lists all the process running and doing other various pipes and filters down the list. If the program is found then it prints the message and exits. If it does not exist then it will print a message to say it’s not running and starting the program, The third line after the “else” statement is the command to start azureus. This can be changed to your relevant program. DISPLAY=:0.0 is only necessary if the program has a GUI. It runs the program what is usually the display on port 0, the one users usually see on the monitor. The remaining parts check if the program has started and prints the relevant message.
Save and close the file.
The script needs execute permissions. Run the following command to do this $ chmod +x /home/danny/myScript.sh
Crontab
crontab is the Linux scheduler. It does things based on time. There are two was to set this up.
GUI / Easy Way
Install gnome-schedule:

$ sudo apt-get install gnome-schedule
Once installed, go to System > Preferences > Scheduled tasks

Click “New” from the toolbar and select “A task that launches recurrently”.

Give it a description and in the command field enter the path to the script. I untick the “No output” option so I can see any errors when we test the script later. Choose the appropriate “Time & Date” for often the script should be ran.

The problem with this method is the customizability of the schedule with every minute the smallest value. To enter a more suitable value click on the “Advanced” radio button and for every 10 minutes enter the */10 and leave all other boxes “*”(asterisk). Click the “Add” button to save the entry.
Highlight and click “Run Task” to test the script.
Command Line / Harder Way
Whilst logged into the user who will run the schedule edit the crontab: $ crontab -e
By default on Ubuntu Nano is the default editor. I use this template in crontab:

# +---------------- minute (0 - 59)

# |  +------------- hour (0 - 23)

# |  |  +---------- day of month (1 - 31)

# |  |  |  +------- month (1 - 12)

# |  |  |  |  +---- day of week (0 - 6) (Sunday=0 or 7)

# |  |  |  |  |


This should help you with entering values but to run the script every 10 minutes the line should be */10 * * * * /home/danny/myScript.sh
Save and exit crontab.
Summary
The script can be customized to check and run any program. Now hopefully any program crashes or if someone closes the program you want running it will automatically start it up and keep it up.





Cron job to start / stop Azureus – can not start azureus
CronHowTo – Ubuntu
Run crontab Every 10 Minutes


Related posts:
Linux Command Line Tips
Setting Default Linux Shell
Linux Terminal Not Auto-completing