Merging multiple files using the cat command

Nothing major today, this is a straightforward case that I was surprised would work with the Linux cat command.

I had a folder with several mp3's that were part of one long mixtape but were split into dozens of files, when they should have really been one big file.

I could have used a tool to fix this, but it can be accomplished natively using a Linux or Mac terminal.

First navigate to the folder where the files are located. If they are in numerical order, that's short and easy.

 cat *.mp3 > ../mylongsong.mp3

This combines all the files into one and dumps in one directory above to avoid an endless loop, depending on the shell you're using.


If the files have arbitrary names, but you can figure out the order, you can use a slightly longer command:

cat 1.mp3 2.mp3 a.mp3 myfav.mp3 wow.mp3 > ../mylongsong2.mp3

The caveat is that all the files need to be encoded the same way and be of the same filetype. It will not merge mp3 with wma, it will not merge a 320kbps mp3 with a 128kbps version.

Installing MySQL 5.6 on CentOS 6

MySQL on CentOS6 is currently limited to version 5.1, which sucks. A lot of modern web applications can benefit of running the most recent version of MySQL (up to 5.6 at the writing of this post), and as a result we will be installing MySQL 5.6 on CentOS 6.x, patched to the latest sub-version.

There are several ways of accomplishing this, but I think it's a good idea to take the software directly from the source.

It's also a pretty good idea to have a backup mechanism, and sadly the free version does not play well with hot backups, which are performed while the database is running in full read/write made.

Percona has a wonderful set of tools, and offer a free hot backup solution for MySQL that works awesomely. I'll provide the instructions to install the tool, you can feel free to peruse their docs to implement your own backup strategy :)

More on Percona Xtrabackup here: http://www.percona.com/doc/percona-xtrabackup/2.2/
More on MySQL Community Server here: http://dev.mysql.com/downloads/mysql/


0. Got root/sudo

1. Get and Install the RPM from MySQL/Oracle

cd /tmp
wget  http://dev.mysql.com/get/mysql-community-release-el6-5.noarch.rpm
rpm -Uvh mysql-community-release-el6-5.noarch.rpm

2. Install MySQL and start / enable service

yum install mysql-community-server 
service mysqld start && chkconfig mysqld on

3. Secure MySQL server

./usr/bin/mysql_secure_installation

4.  Install Percona with repos

rpm -Uvh http://www.percona.com/downloads/XtraBackup/XtraBackup-2.2.9/binary/redhat/6/x86_64/percona-xtrabackup-2.2.9-5067.el6.x86_64.rpm

 Verify successful install and check version

xtrabackup --version

--EOF

Pluggable Authentication Modules (PAM) - some basic tricks on CentOS 6

I've been playing around with PAM on a couple distros recently, and I thought I'd share some quick tips and tricks in setting up a secure CentOS 6 Linux multi-user environment. Whilst these are not bulletproof password policies, they are a step beyond the default distribution configuration and are not too complex that the users would be bugging you, the friendly neighbourhood sysadmin.

As usual, any feedback is appreciated, so drop me a line: noveck@woblag.com. Once it gets past the spam filters, I'll try my best to respond asap.

1. Use PAM to disable the use of null passwords in user Accounts.

vi /etc/pam.d/system-auth

Find line 

password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok

Remove/delete nullok option, so the line now reads:
password sufficient pam_unix.so md5 shadow try_first_pass use_authtok

save and close file

2. Use PAM to prevent re-using/recycling passwords .

This example prevents the use of the last 3 passwords.

vi /etc/pam.d/system-auth
find line
password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok

Add to end of line
password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok remember=3

save and close file

3. Set password minimum length

This example sets the minimum password length to 8 characters.

vi /etc/pam.d/system-auth

find line
password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok

Add new line BEFORE
passwd password requisite pam_cracklib.so minlen=8
save and close file

4. Configure server to deny access with multiple incorrect login attempts

This example temporarily denies access after 5 attempts. The temporary lockout time can also be configured for a certain time, which will be set to 1 hour (3600 seconds) in this example.

vi /etc/pam.d/system-auth

Add the following line to end of file
auth required pam_tally.so onerr=fail deny=5 unlock_time=3600

save and close file

--END

Fedora 20 as a (viable!) Windows Desktop Replacement

So I've been bound to windows desktops for so long, that it's been my second nature for workstations. My de facto preference for most server environments are Linux, so I've been between both worlds for quite some time.

My Windows7 machine suffered an OS failure a couple months ago, after almost 4 years of constant everyday use. I installed Windows 8 and was relatively happy with it until it just decided to screw over my WIFI. Nobody messes with my WIFI.

I finally decided to chuck the 15 year Redmond tether and go for broke. I'm gonna run Fedora 20 as a desktop environment, and I'm never looking back. Or so I hope.

Anyhow, FC20 is nice, but to make the environment a bit more aesthetic and a bit more intuitive for use by longtime Windows users I've compiled a "Sanity list". These make everyday use a bit less complicated and quite easy to forget that you're running Linux, traditionally seen as a big, bad, complex beast.

I'll explain why in line, followed by the instructions to accomplish on Fedora 20. This assumes a base Fedora 20 installation has been completed, with a default Gnome desktop.

If you ever decide to take the plunge, this can probably help you break the windows habit ;)

Why Fedora?

Tweak List as of 06-OCTOBER-2014

- install cinnamon, a pretty good looking desktop environment.
This can be selected from the settings icon on the default login screen and it will be the future default afterwards.

sudo yum groupinstall cinnamon

- install infinality, some font eyecandy.
There are a number of styles, I prefer the OSX style on my 4 year old Dell Latitude display

sudo rpm -Uvh http://www.infinality.net/fedora/linux/infinality-repo-1.0-1.noarch.rpm
sudo yum -y install freetype-infinality fontconfig-infinality
cd /etc/fonts/infinality/
./infctl.sh setstyle osx 

(personal pref - more options are in README documentation)

- install MSTTCoreFonts
You have to admit that MS ships with some solid fonts. If you want to avoid formatting issues with opening MS Office docs with LibreOffice, this is a pretty good idea.

sudo yum install cabextract
sudo yum install http://sourceforge.net/projects/mscorefonts2/files/rpms/msttcore-fonts-installer-2.6-1.noarch.rpm

- install vlc
This is another personal preference; VLC is a solid media player and works great on Windows as well as Linux

su -c 'yum localinstall --nogpgcheck http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm'
sudo yum install vlc

- install flash player
As much as I didn't want to, there are still several sites that I use that are flash based. A necessary evil.

rpm -ivh http://linuxdownload.adobe.com/adobe-release/adobe-release-i386-1.0-1.noarch.rpmrpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linuxyum check-updateyum install flash-plugin nspluginwrapper alsa-plugins-pulseaudio libcurl

- install google chrome
Chrome is a great addition to Fedora, compliments the use of Firefox, which I personally find to be a bit bloated now.

cat << EOF > /etc/yum.repos.d/google-chrome.repo
[google-chrome]
name=google-chrome - \$basearch
baseurl=http://dl.google.com/linux/chrome/rpm/stable/\$basearch
enabled=1
gpgcheck=1
gpgkey=https://dl-ssl.google.com/linux/linux_signing_key.pub
EOF
yum install google-chrome-stable

- install skype
Skype, almost a universal tool for free webcalling. I installed it because I use it a lot for international calling to the US for free.

wget http://download.skype.com/linux/skype-4.2.0.11-fedora.i586.rpmsudo yum install skype-4.2.0.11-fedora.i586.rpm

- install dropbox
I've been using dropbox on all my boxes, it's a great way to keep some personal docs on the cloud and have multiple versions for backup.

cat << EOF > /etc/yum.repos.d/dropbox.repo
[Dropbox]
name=Dropbox Respository
baseurl=http://linux.dropbox.com/fedora/19/
gpgkey=http://linux.dropbox.com/fedora/rpm-public-key.asc
EOF
sudo yum install nautilus-dropbox

- install google talk
I consider this an optional item. You may or may not actually need this.

wget http://dl.google.com/linux/direct/google-talkplugin_current_i386.rpm
yum install google-talkplugin_current_i386.rpm --nogpgcheck

- install teamviewer
TeamViewer is an excellent desktop sharing/control tool that comes in handy to access my laptop remotely if needed.

wget http://download.teamviewer.com/download/teamviewer_linux.rpm

Additional tweaks:

- tweak boot timeout behaviour
Shorten the time to countdown the OS selection

vi /etc/default/grub
GRUB_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

- logind tweaks
These control some suspend/hibernate options when the lid is closed. You can decide if you need these.

vi /etc/systemd/logind.conf
HandleSuspendKey=ignore
HandleHibernateKey=ignore
HandleLidSwitch=ignore
HandlePowerKey=poweroff

- eyecandy that can be installed through the extensions menu
(Settings -> Extensions)
Opacify


That's it for now. I'll add to this post and drop a datestamp with any new additions!

Image courtesy http://www.fedoraproject.org

Fedora 20 - Missing WIFI driver/support on clean install

I've started a little experiment on porting a crashed windows 7 Laptop (Dell Inspiron 1525) over to Linux. Why Linux at this point? The crash was largely due to the infamous Windows Update Issue. For me that was the straw that broke the camel's back.

The experiment part of this update comes from the fact that the user has never really used Linux before, so this is really a true test of the user-friendliness of the OS, once initially set up. My weapon of choice was Fedora 20, largely because I'm entrenched in the RHEL distribution tree for almost everything that I do, so it's naturally easier for me to troubleshoot quickly.

The installation and initial configuration went pretty smoothly, except for the fact that out of the box, WIFI appeared nonexistent. This was not a big problem, as it worked on a Kali Linux Live USB, so I knew that the hardware was fine. From the old install I knew that the device was Broadcom based, so I had a launch point.

Credit to http://wireless.kernel.org/en/users/Drivers/b43 for thoroughly documenting the resolution of this issue.

First check the device for support:
0. As root:
lspci -vnn -d 14e4:

It spat out some device information, including the model, in my case the Broadcom Corporation BCM4312, which was supported by the b43 driver. I compared the output to the corresponding CHIP ID segment on the table
Taken from: http://wireless.kernel.org/en/users/Drivers/b43

PCI-ID	Supported?	Chip ID	Modes	PHY version	Alternative
14e4:4315	yes	BCM4312	b/g	LP (r1)	wl

The Fedora specific instructions are as follows:
1. Install the firmware extractor tool

su -

yum install b43-fwcutter wget

2. Install the driver

Define the Firmware path (Fedora specific)

export FIRMWARE_INSTALL_DIR="/lib/firmware"
Download and extract the Broadcom driver

wget http://mirror2.openwrt.org/sources/broadcom-wl-5.10.56.27.3_mipsel.tar.bz2

tar xjf broadcom-wl-5.10.56.27.3_mipsel.tar.bz2

Install the driver

sudo b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" broadcom-wl-5.10.56.27.3/driver/wl_apsta/wl_prebuilt.o

3. Reboot

These steps were sufficient for me, as soon as I rebooted the WIFI was available to connect. If these steps do not solve your issue, you may need to blacklist older drivers. Take a read here: http://wireless.kernel.org/en/users/Drivers/b43

Maybe I'll break the chains of Microsoft bondage on my own laptop - which oddly enough, works swimmingly on a fresh Windows 8.1 installation. We'll see.

-noveck

Introduction to Linux Systems Administration (a Workshop)

I recently delivered a free 5 (half) day workshop on an Introduction to Linux Systems Administration. The information was culled from a range of web sources, classes and personal notes, so all credit to the respective sources. All practicals were tested on a vanilla CentOS 6.5 Virtual Machine on VMWare Player, which is free for personal use.

At the end of the workshop, I asked the participants to describe what they thought of Linux using one or two words, and this was the result:

I'd like to share the PDF version of the presentation and if you have any feedback, drop me a line. It's very much a work in progress and I welcome your contributions!

-Noveck

Migrating a Virtual Machine from VMWare Player to ESXi

This post covers the migration of a virtual machine from a VMWare Player environment, which is located on my workstation (Windows 7 64-bit), to a VMWare ESXi server in my datacenter.

Both are the free versions, so they don't have all the fancy bells and whistles as the awesome licensed versions.

It took a bit of doing, but it's relatively straightforward.


1. Upgrade VMWare player (if necessary)
I realized that I was using version 3.0, and was a 'few' versions behind. Newer versions contain the OVFTool, which we will use to create the ESXi ready OVF.
Visit here: http://www.vmware.com/products/player


2. Upgrade and Reboot your pitiful workstation.

3. Read the VMWare OVFTool guide. Or not.

4. Login to the Virtual Machine in VMWare Player and uninstall the VMWare Tools. Reboot VM.

5. When VM boots, ignore any driver errors. Do a clean shutdown.

6. Export the OVF from the VM
Open Command Prompt as Administrator
cd C:\Program Files\VMWare\VMWare OVF Tool

Make sure the tool works, run the help
ovftool -h

You should be presented with a range of flag options.

Export the OVF
ovftool "C:\Path to VMname.vmx" "C:\Path to place OVF"
If the output does not look like this, it might be a good idea to check the documentation.

7. Import the OVF Into VMWare ESXi
Login to your ESXi Host
Click File -> Deploy OVF Template
Browse to "C:\Path to place OVF" as specified in step 6.
Use defaults, or configure accordingly.
When completed boot VM in ESXi, enable the network adapter and update the IP/Hostname or any other relevant configuration.

That's it!