Ubuntu – Change Hostname Permanently Using the Command Line

On Ubuntu the hostname is stored in both the /etc/hosts and /etc/hostname files. There are several ways that we can change the hostname in these files.

1. Manually Edit the hostname

We can manually edit these files using a basic text editor like nano:

sudo nano /etc/hosts
sudo nano /etc/hostname

In /etc/hostname simply overwrite the existing hostname with a new one. In /etc/hosts you will find the hostname on the line beginning 127.0.0.1 – overwrite only the hostname with the new one, and then reboot.

Editing /etc/hosts using nano

sudo reboot

2. Use sed to change the hostname

Another way to achieve the same goal is to use the sed command to replace the existing hostname with a new one.

For example, my Ubuntu Server has the default hostname of ‘ubuntu’.

Use the hostname command to check what your hostname is.

With sed we can look for our hostname (in /etc/hosts and /etc/hostname) and then replace it with the desired new-hostname:

sudo sed -i 's/ubuntu/new-hostname/g' /etc/hosts
sudo sed -i 's/ubuntu/new-hostname/g' /etc/hostname

Reboot:

sudo reboot

3. Write a Bash Script

It’s always handy to have a script to do things – so here is a quick bash script that I put together that uses sed to change the hostname and then reboot:

#!/bin/bash
#Assign existing hostname to $hostn
hostn=$(cat /etc/hostname)

#Display existing hostname
echo "Existing hostname is $hostn"

#Ask for new hostname $newhost
echo "Enter new hostname: "
read newhost

#change hostname in /etc/hosts & /etc/hostname
sudo sed -i "s/$hostn/$newhost/g" /etc/hosts
sudo sed -i "s/$hostn/$newhost/g" /etc/hostname

#display new hostname
echo "Your new hostname is $newhost"

#Press a key to reboot
read -s -n 1 -p "Press any key to reboot"
sudo reboot

Ubuntu Server – Apache2: Could not reliably determine the server’s fully qualified domain name, using 127.0.1.1 for ServerName

Restarting the Apache Web Server on Ubuntu Server (12.04 at the time of writing) gives me the following error:

apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName

To fix this error add ServerName localhost to /etc/apache2/httpd.conf, as follows:

echo 'ServerName localhost' | sudo tee -a /etc/apache2/httpd.conf

Restart Apache to make sure that the issue is resolved:

sudo /etc/init.d/apache2 restart

Ubuntu Server – Unattended Installation (Custom CD)

I’ve lost count of the number of times that I have installed Ubuntu Server on my VMware vSphere box – so I finally looked in to performing an unattended install.

I could have setup DHCP and TFTP servers and done PXE boot from images over the network – but I wanted to work on something quicker than that (and I don’t have that much spare RAM on my vSphere box as it is).

So I settled on re-mastering an Ubuntu Server .iso image. The result is an unattended install, except for the initial boot screen (where I need to select a minimal virtual machine installation anyway).

The following steps were performed on Ubuntu Desktop.

Download Ubuntu Server – I am using the 32 bit version of Ubuntu 12.04.

Open a Terminal and create a directory to mount the Ubuntu Server iso to.

sudo mkdir -p /mnt/iso

The -p switch is very useful as it allows you to create a directory structure which does not already exist (as opposed to creating a single directory).

Change directory to Downloads:

cd Downloads

I renamed my download UbuntuServer.iso.

Mount UbuntuServer.iso to /mnt/iso:

sudo mount -o loop UbuntuServer.iso /mnt/iso

Create a directory and copy the mounted Ubuntu Server files:

sudo mkdir -p /opt/serveriso
sudo cp -rT /mnt/iso /opt/serveriso

The -r switch copies directories recursively and -T specifies no (singular) target directory.

Now we have a copy of our Ubuntu .iso to work on in /opt/serveriso – but we need to make these files writable:

sudo chmod -R 777 /opt/serveriso/

With this preparation done we can start customizing things.

If we look at the isolinux/langlist file we see all the supported languages listed that Ubuntu supports (in an abbreviated format):

am
ar
ast
be
bg ...

I am only interested in an English install so I am going to overwrite the contents of isolinux/langlist with the single abbreviation for English, which is “en”.

cd /opt/serveriso
echo en >isolinux/langlist

This stops the language selection menu from appearing during installation.

The next step of the process is to create a kickstart file – this will provide the server install with the answers to the various questions asked during installation, such as timezone, username, password, partition structure and so on.

Install Kickstart Configurator:

sudo apt-get install system-config-kickstart

Click the Dash button and type kickstart and then click on the kickstart application.

Obviously you should customize your settings as you see fit – I have provided mine for reference.

Basic Configuration: Set Timezone

Installation Method: Choose the CD-ROM installation method

Partition Options: Add an ext4 partition to the root file system that fills all unused space on the disk

Partition Options: Add a swap file system that uses the recommended swap size

Network Configuration: Add network device eth0 and set to DHCP

User Configuration: Provide username and password

Click File, Save File and save the kickstart file ks.cfg to /opt/serveriso.

While using the Kickstart Configurator you may have noticed that the Package Selection screen did not work. Fortunately we can manually edit the ks.cfg file so that the packages that we want are installed during Ubuntu Server installation.

At the end of ks.cfg add %packages and then list the packages that you want installed. I chose to install nano, openssh-server and open-vm-tools:

%packages
nano
openssh-server
open-vm-tools --no-install-recommends

–no-install-recommends installs open-vm-tools in headless mode.

Now we need to configure the CD boot command line to use the kickstart ks.cfg file.

Browse to and open /opt/serveriso/isolinux/txt.cfg.

We need to edit the append line of the default install section at the top of the file.

At the end of the append line add ks=cdrom:/ks.cfg. You can remove quiet – and vga=788.

My append line is as follows:

append  file=/cdrom/preseed/ubuntuserver.seed initrd=/install/initrd.gz ks=cdrom:/ks.cfg

The final step is to create a new Ubuntu Server .iso using this command:

sudo mkisofs -D -r -V "ATTENDLESS_UBUNTU" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o /opt/autoinstall.iso /opt/serveriso

The finished .iso is /opt/autoinstall.iso.

Test your .iso in a virtual machine to make sure that everything works as it should.

The minimal interaction that I need to set my Ubuntu Server install going is documented below:

Press the Enter key to confirm the English language selection

Press F4, select Install a minimal virtual machine, and then press Enter

Press Enter to install Ubuntu Server

From here installation continues without any further input being required.

Sources: http://askubuntu.com/questions/122505/how-do-i-create-completely-unattended-install-for-ubuntu

Ubuntu – Ripping Audio CDs to FLAC and MP3 with abcde

I have an aging laptop that with Ubuntu 12.04 (Lucid) installed that I wanted to use to rip my CD collection to FLAC and MP3.

I didn’t want to have to use a GUI and I wanted the process to be as automated as possible – so I settled on the command line tool abcde (A Better CD Encoder).

First I installed all of the software required:

sudo apt-get install abcde cd-discid lame cdparanoia id3 id3v2

Then I made a backup of the abcde configuration file:

cp /etc/abcde.conf /home/myusername

I then copied and pasted a great abcde.conf file that I found online to /etc/abcde.conf:

sudo nano /etc/abcde.conf

This is the abcde.conf that I used:

# -----------------$HOME/.abcde.conf----------------- #
# 
# A sample configuration file to convert music cds to 
#       MP3 format using abcde version 2.3.99.6
# 
#       http://andrews-corner.org/abcde.html
# -------------------------------------------------- #

# Specify the encoder to use for MP3. In this case
# the alternatives are gogo, bladeenc, l3enc, xingmp3enc, mp3enc.
MP3ENCODERSYNTAX=lame 

# Specify the path to the selected encoder. In most cases the encoder
# should be in your $PATH as I illustrate below, otherwise you will 
# need to specify the full path. For example: /usr/bin/lame
LAME=lame

# Specify your required encoding options here. Multiple options can
# be selected as '--preset standard --another-option' etc.
LAMEOPTS='--preset extreme' 

# Output type for MP3.
OUTPUTTYPE="mp3"

# The cd ripping program to use. There are a few choices here: cdda2wav,
# dagrab, cddafs (Mac OS X only) and flac.
CDROMREADERSYNTAX=cdparanoia            

# Give the location of the ripping program and pass any extra options:
CDPARANOIA=cdparanoia  
CDPARANOIAOPTS="--never-skip=40"

# Give the location of the CD identification program:       
CDDISCID=cd-discid            

# Give the base location here for the encoded music files.
OUTPUTDIR="$HOME/music/"               

# Decide here how you want the tracks labelled for a standard 'single-artist',
# multi-track encode and also for a multi-track, 'various-artist' encode:
OUTPUTFORMAT='${OUTPUT}/${ARTISTFILE}-${ALBUMFILE}/${TRACKNUM}.${TRACKFILE}'
VAOUTPUTFORMAT='${OUTPUT}/Various-${ALBUMFILE}/${TRACKNUM}.${ARTISTFILE}-${TRACKFILE}'

# Decide here how you want the tracks labelled for a standard 'single-artist',
# single-track encode and also for a single-track 'various-artist' encode.
# (Create a single-track encode with 'abcde -1' from the commandline.)
ONETRACKOUTPUTFORMAT='${OUTPUT}/${ARTISTFILE}-${ALBUMFILE}/${ALBUMFILE}'
VAONETRACKOUTPUTFORMAT='${OUTPUT}/Various-${ALBUMFILE}/${ALBUMFILE}'

# Put spaces in the filenames instead of the more correct underscores:
mungefilename ()
{
  echo "$@" | sed s,:,-,g | tr / _ | tr -d \'\"\?\[:cntrl:\]
}

# What extra options?
MAXPROCS=2                              # Run a few encoders simultaneously
PADTRACKS=y                             # Makes tracks 01 02 not 1 2
EXTRAVERBOSE=y                          # Useful for debugging
EJECTCD=y                               # Please eject cd when finished  

I found that this configuration work very well for me and I especially liked that it put my FLAC and MP3 files into different folders.

The only issue that I had was that abcde would ask me if I wanted to edit metadata for the CD that I was ripping, requiring user input to continue.

Fortunately I found a setting in my backed-up abcde.conf that lets abcde run in non-interactive mode:

# Define if you want abcde to be non-interactive.
# Keep in mind that there is no way to deactivate it right now in the command
# line, so setting this option makes abcde to be always non-interactive.
#INTERACTIVE=n

So, I simply added the following line to my abcde.conf and then I was set:

INTERACTIVE=n

All I have to do now is simply put a CD in the CD-ROM drive and then open a terminal and type:

abcde

Then when the CD ejects I simply put in the next CD, press the up arrow to bring up the last terminal command (abcde), and then press the Enter key to start the process over again.

Other than that I shared my music folder so that I can copy the FLAC and MP3 files to my desktop for backup.

All in all a great way to back up my CD collection with minimal fuss and interaction!

Sources: Ubuntu Forum

Ubuntu Server – Very Quick FTP Setup

To get an FTP daemon running on Ubuntu Server we will install vsftpd (Very Secure FTP Daemon) as follows:

sudo apt-get update
sudo apt-get install vsftpd

The next step is to configure vsftpd by editing the /etc/vsftpd.conf file. Issue the following commands to install the nano editor (if you haven’t installed it before) and edit the file:

sudo apt-get install nano
sudo nano /etc/vsftpd.conf

The basic configuration of vsftpd.conf involves simple editing and un-commenting of the existing parameters:

Un-commenting is the removal of the # sign from the start of a line. For example changing #local_enable=YES to local_enable=YES (which we will do later).

• To disable anonymous access change anonymous_enable=YES to anonymous_enable=NO.
• Un-comment #local_enable=YES to allow local users to login to the FTP server.
• Un-comment #write_enable=YES if you want users to be able to upload to the FTP server.

Vsftp.conf contains an explanation of its parameters – so it should be relatively self-explanatory if you wish to configure other options.

The final step is to restart the vsftp daemon. On older Ubuntu servers you will probably use sudo /etc/init.d/vsftpd restart but a more recent installation will prefer:

sudo service vsftpd restart

Enjoy!

Ubuntu – Using apt-file to find missing packages

In a previous post I was unable to run the add-apt-repository command because python-software-properties was not installed on Ubuntu Server. I found the solution (install python-software-properties) by searching the internet but I could have installed apt-file and found the answer myself.

So let’s install apt-file and see how to quickly find the package that contains add-apt-repository.

Open a terminal and issue these commands:

sudo apt-get update
sudo apt-get install apt-file

I was prompted to update apt-file but you can do it manually using the command line:

apt-file update

Now that apt-file is installed and up-to-date let’s issue a search for add-apt-repository:

apt-file search add-apt-repository

The result of the search is as follows:

$ apt-file search add-apt-repository
python-software-properties: /usr/bin/add-apt-repository
python-software-properties: /usr/share/man/man1/add-apt-repository.1.
gz

As you can see the result tells us that the file that we are looking for is in the python-software-properties package. Once that is installed we can run the add-apt- repository command.

Apt-file is a great tool – and I am sure that I will be using it again in the near future!

xbmcbuntu 11 (Eden) – YouTube Plugin 3.1 Playback Issue

I recently installed the TubeToTV extenstion for the Chromium browser in Ubuntu 12.04 so that I could send YouTube videos from my laptop to my xmbc Media Center. I was surprised when I got a Playback error message.

I soon found that the issue was not with the TubeToTv extension but with the YouTube (3.1) Plugin on xbmc.

Fortunately a kind fellow called anteo had already stepped in to fix the extension – so I can now play YouTube videos on xbmc and use the TubeToTV extenstion too!

The fix is as follows – open a terminal and shh into your xbmc:

ssh user@ipaddress

Use the username and IP adddress of your xmbc.

Retrieve two plugins using wget:

wget https://dl.dropbox.com/u/33024933/plugin.video.youtube.zip
wget https://dl.dropbox.com/u/33024933/script.module.simple.
downloader.zip

Update: The above links are no longer working and so I have uploaded the files to dropbox myself:

• http://dl.dropbox.com/u/4490912/plugin.video.youtube.zip
• http://dl.dropbox.com/u/4490912/script.module.simple.downloader.zip

Next uninstall the YouTube 3.1 plugin from xbmc and then install the two plugins that you just downloaded.

Many thanks to anteo for the fix!

Ubuntu 12.04 – Dell Vostro 3750 – No Sound When Headphones are Plugged in (Fixed)

Since installing Ubuntu 12.04 on my Dell Vostro 3750 I have had issues with no sound coming through my headphones.

I thought that I had resolved the issue in a previous blog post but recently the problem has resurfaced. I tired reverting to my original /usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones.conf file but this did not work.

It might have some bearing on the issue that I am dual booting with Windows 7 – but I am not sure that this is necessarily the problem.

When I run alsamixer (from the terminal) my speaker volume becomes muted when I plug in my headphones.

The headphone column state does not change at all.

My first stop when looking at this issue again was the Ubuntu Sound Troubleshooting Page. I looked at a few items after step 9 but I tried evrything up to step 9 to no avail. I mention this as I do not know if these steps impacted the current fix that I am using.

This bug report contains the fix that currently works for me. Open a Terminal and issue the following commands:

sudo nano /usr/share/pulseaudio/alsa-mixer/paths/analog-output-
headphones.conf

Comment out the following line as shown:

[Jack_InputDevice]
#required-any = any

Save the file and then issue this command to restart pulseaudio:

pulseaudio -k

So far I have had no issues with this fix and I have rebooted and plugged and un-plugged my headphones – sound switches between the headphones and speaker just fine again.

xbmc – 100% CPU Usage in VMware vSphere 4.x

I installed xbmc (eden) in VMware vSphere this evening to try to learn how to configure my HDHomeRun, so that I can record TV shows on my HTPC.

I found however that xbmc.bin was using almost 100% CPU after installation.

The solution was to edit home/.xbmc/userdata/advancedsettings.xml and add the following:

<gui>
<algorithmdirtyregions>1</algorithmdirtyregions>
<nofliptimeout>0</nofliptimeout>
</gui>


After a reboot my CPU usage was normal – hurrah!

Sources:

http://forum.xbmc.org/showthread.php?tid=126468
http://wiki.xbmc.org/index.php?title=Userdata

ViMP – Upgrading From Version 2.2.x to 2.5 (Ubuntu Server 10.4 Lucid)

Yesterday I finally upgraded ViMP Community Edition to 2.2.x and so today I am upgrading to 2.5.x.

At the time of writing the latest version of ViMP is vimp.framework-2.5.4-r19900-community.tar.gz – which can be downloaded from here.

For clarification my system variables are as follows (obviously you may need to change them if yours are different):

• ViMP installation directory – /var/www/showvid/data/

• MySQL user – root

• MySQL ViMP database – showvid

The upgrade process was as follows.

First backup the ViMP directory and copy the ViMP tarball to your server.

Copy the tarball to /var/www/showvid/data:

sudo cp vimp.framework-2.5.4-r19900-community.tar.gz 
/var/www/showvid/data/

Change directory to /var/www/showvid/data/:

cd /var/www/showvid/data/

Extract the vimp-framework tarball:

sudo tar xvzf vimp.framework-2.5.4-r19900-community.tar.gz

Delete lib/auth/stAuthProvider.php

cd /lib/auth/
sudo rm stAuthProvider.php

Next we need to run the data/sql/updates.sql file from the ViMP tarball – make sure that you extract the tarball on your computer so that you can import it to your server.

Note: there are other .sql files in the sql folder but they are only used if you have modules installed etc.

Updates.sql can be run from the command line but I found it easier to use phpmyadmin – which can be installed as follows:

sudo apt-get install phpmyadmin

I selected Apache2 as the webserver to reconfigure and then selected No to configure a database for phpmyadmin. Open a browser and open phpmyadmin on your ViMP server: http:\\<server-ip>\phpmyadmin. Log in with root and your mysql password.

Select the showvid database in the left hand panel and then click the import tab. Click the Browse button and select updates.sql in the data/sql folder. Then click the Go button.

Finally change directory to /var/www/showvid/data and rebuild the ViMP installation:

sudo ./symfony rebuild
sudo ./symfony i18:import

I did get an error when I imported updates.sql but ViMP did successfully upgrade.