Preserving your working directory in gnome-terminal

I use gnome-terminal for most of my hacking. In fact, I use it so much, that I’ll often have multiple tabs open for a particular project. Here’s my workflow:

1. Control+Alt+t (My shortcut to open a new gnome-terminal window.)
2. cd ~/code/some_cool_hack/ # directory of some cool hack
3. Control-Shift-t (Shortcut to open a new gnome-terminal tab.)
4. Hack, hack, hack…

The problem is that the new tab that I’ve created will have a $PWD of ~, instead of keeping the $PWD of ~/code/some_cool_hack/, which is the project I’m working on!

The solution is to add:

# including this ensures that new gnome-terminal tabs keep the parent `pwd` !
if [ -e /etc/profile.d/vte.sh ]; then
    . /etc/profile.d/vte.sh
fi

to your ~/.bashrc. Now everything works perfectly!

Many thanks to Matthias Clasen and Ray Strode for figuring this one out!

One side note: this used to be the default, but for some reason it broke around Fedora 19 or 20. Maybe it had to do with my fancy prompt, but everything is working great now.

Happy Hacking,

James

 

Speaking at SCALE today!

I’ll be giving a talk at SCALE today about automatically deploying GlusterFS with Puppet-Gluster and Vagrant. I’ll be giving some live demos, and this will cover some of the material from:

Automatically deploying GlusterFS with Puppet-Gluster + Vagrant!

and it will contain excerpts from:

Screencasts of Puppet-Gluster + Vagrant

I’ll also be talking about some new upcoming features, and am happy to answer all of your questions!

The talk will be part of Infrastructure.next and is starting around 1:30 or 2pm in the Century AB room.

If you’re not able to attend, or you’d like a more personalized demo, send me a note! I’ll be around for the next few days.

Thanks to Joe Brockmeier and John Mark Walker for hosting the event and sending me here.

Happy Hacking,

James

 

Scathing review of the Lenovo X240

I’m using a Lenovo X201 with 8GiB of RAM. Apart from some minor issues, I’ve been very satisfied with this laptop. It’s over four years old, and so I decided to see what’s available on the horizon. I did not buy an X240 because of the following reasons:

The X240 has only one slot for RAM and thus supports a maximum of 8GiB.

I think it’s pretty ridiculous for any successor to the X230 to support less RAM. In and of itself this is a deal breaker! My X201 has 8GiB, and I wish it had more! It doesn’t make sense to settle for less on new kit. In other words, Lenovo is stating that 8GiB ought to be enough for anybody.

The X240 keyboard is missing buttons.

The X201 keyboard has PageUp and PageDown keys in addition to the Forward and Back buttons which are located above the Left and Right arrow keys. It also has dedicated Insert and Delete keys. This is all to be expected, and is awesome.

The X240 removes the dedicated Forward and Back buttons, and replaces them with the (now relocated) PageUp and PageDown keys. To use the Forward and Back buttons, you now need an extra finger to hold the Fn button.

If that wasn’t bad enough, the Insert key now shares a button with the End key, which makes common Shift+Insert sequences near impossible to anyone that isn’t either a cephalopod or an Emacs user. Time to update the pedals to include an Fn key.

The X240 keyboard is missing buttons.

It’s also worth mentioning that the dedicated volume controls are gone.

The X240 “Trackpad”/”Touchpad” is now buttonless and unusable.

The mechanics of the new Touchpad makes it unusable! It has no buttons, and instead it feels like it is travelling 1cm vertically when it is pressed! This throws off any fine positioning you had with your cursor. Try it for five minutes, and you’ll quickly learn that this alone ensures that this machine can only be used as a desktop. Many, many users are complaining about the feel of the new pad. This feels like an attempt to imitate the look of an Apple product, instead of trying to maintain the functionality of the X series, except that the hardware isn’t very good.

Interlude…

I could deal with the below issues, if my top three (above) issues weren’t strong deal breakers! They are all easy to fix too! I hope these are addressed so that I can post a follow up “rave” article. ;)

Other issues/differences…

The X240 has a new, incompatible power adapter.

Lenovo has decided it needs to squeeze more money out of users by introducing new, backwards-incompatible technology. To this end, the well-known barrel adapter is now gone, and it has been replaced by a strange rectangle. You might as well throw out all your old power bricks, as Lenovo has said they won’t offer a compatibility adapter. Apparently, they used to sell such an adapter, but it has been discontinued.

The X240 has a new, incompatible docking bay.

If you were a fan of docking, you’ll now have to purchase a new bay.

The X240 has a combined microphone/headphone jack.

Minimalist designs and the abundance of cheap phone headsets has reduced the dual jack design to a combined single jack. I don’t like the change, but I realize there’s not much that can be done to prevent it.

Lenovo has a terrible warranty program.

Getting a hardware replacement with the Lenovo “return to depot” service can take about two weeks. Bringing your laptop in to a service centre is equally challenging. The locator database is out of date, and once you do find a service centre, many are unwilling to accept your hardware because they’re backlogged with work! If you are lucky enough to get a part replaced, hope that it isn’t defective or DOA. I had to go through three rounds of bad motherboards graphics on my X201. The on-site service is a good option if you can afford it.

Conclusion

Instead of iterating and improving on the much-loved X series, Lenovo has decided to sacrifice its followers in trying to appeal to a low-end laptop market. Once the model of power and portability, the X series is now designed for users who are afraid of having too many buttons or too much RAM.

The X220 and X230 are not available for sale anymore. The X250 isn’t due before 2015. I’ve extended the warranty of my X201 to the maximum of five years. Let’s hope someone at Lenovo reads this article and can make a difference before it’s too late. I’m happy to consult and demo new hardware if you contact me. I’d genuinely like to help.

Happy Hacking,

James

Show the exit status in your $PS1

As an update to my earlier article, a friend gave me an idea of how to make my $PS1 even better… First, the relevant part of my ~/.bashrc:

ps1_prompt() {
	local ps1_exit=$?

	if [ $ps1_exit -eq 0 ]; then
		#ps1_status=`echo -e "\[\033[32m\]"'\$'"\[\033[0m\]"`
		ps1_status='\$'
	else
		ps1_status=`echo -e "\[\033[1;31m\]"'\$'"\[\033[0m\]"`

	fi

	ps1_git=''
	if [ "$(__git_ps1 %s)" != '' -a "$(__git_ps1 %s)" != 'master' ]; then
		ps1_git=" (\[\033[32m\]"$(__git_ps1 "%s")"\[\033[0m\])"
	fi

	PS1="${debian_chroot:+($debian_chroot)}\u@\h:\[\033[01;34m\]\w\[\033[00m\]${ps1_git}${ps1_status} "
}

# preserve earlier PROMPT_COMMAND entries...
PROMPT_COMMAND="ps1_prompt;$PROMPT_COMMAND"

If you haven’t figured it out, the magic is that the trailing $ prompt gets coloured in red when the previous command exited with a non-zero value. Example:

james@computer:~$ cdmkdir /tmp/ttboj # yes, i built cdmkdir
james@computer:/tmp/ttboj$ false
james@computer:/tmp/ttboj$ echo ttboj
ttboj
james@computer:/tmp/ttboj$ ^C
james@computer:/tmp/ttboj$ true
james@computer:/tmp/ttboj$ cd ~/code/puppet/puppet-gluster/
james@computer:~/code/puppet/puppet-gluster$ # hack, hack, hack...

You can still:

$ echo $?
42

if you want more specifics about what the exact return code was, and of course you can edit the above ~/.bashrc snippet to match your needs.

Hopefully this will help you be more productive, I know it’s helping me!

Happy hacking,

James

Screencasts of Puppet-Gluster + Vagrant

I decided to record some screencasts to show how easy it is to deploy GlusterFS using Puppet-Gluster+Vagrant. You can follow along even if you don’t know anything about Puppet or Vagrant. The hardest part of this process was producing the actual videos!

If recommend first reading my earlier articles if you’re planning on following along:

• Vagrant on Fedora with libvirt

• Vagrant vsftp and other tricks

• Vagrant clustered SSH and ‘screen’

• Automatically deploying GlusterFS with Puppet-Gluster + Vagrant!

Without any further delay, here are the screencasts:

Part 1: Intro, and provisioning of the Puppet server.

Part 2: Initial building of the Gluster hosts.

Part 3: Finishing the Gluster builds.

Part 4: GlusterFS client mounting and tests.

Part 5: Mixed bag of code, infrastructure tours, examples and other details.

I hope you enjoyed these videos. Thank you to the Gluster.org community for hosting them. If you liked these videos, please consider sponsoring some of my work, or making a donation!

As a side note, the only screencast tool that worked was gtk-recordmydesktop, however it deleted my second recording (which had to be re-recorded) and the audio stopped working one minute into my third recording (which had to then be separately recorded, and mixed in). Amazingly, pitivi was the only tool which worked to properly mix them together!

Happy Hacking,

James

PS: Please note, you may not sell, edit, redistribute, perform, or host these videos elsewhere without my permission. I especially don’t want to see them on youtube until Google let’s me unlink my youtube account! If you do want my permission to use these videos for something, contact me, and we can work something out. I’ll surely allow it if it’s not for something evil. If you’d rather have an interactive, live demo, let me know!

Building base images for Vagrant with a Makefile

I needed a base image “box” for my Puppet-Gluster+Vagrant work. It would have been great if good boxes already existed, and even better if it were easy to build my own. As it turns out, I wasn’t able to satisfy either of these conditions, so I’ve had to build one myself! I’ve published all of my code, so that you can use these techniques and tools too!

Status quo:

Having an NIH problem is bad for your vision, and it’s best to benefit from existing tools before creating your own. I first tried using vagrant-cachier, and then veewee, and packer. Vagrant-cachier is a great tool, but it turned out not being very useful because there weren’t any base images available for download that met my needs. Veewee and packer can build those images, but they both failed in doing so for different reasons. Hopefully this situation will improve in the future.

Writing a script:

I started by hacking together a short shell script of commands for building base images. There wasn’t much programming involved as the process was fairly linear, but it was useful to figure out what needed getting done.

I decided to use the excellent virt-builder command to put together the base image. This is exactly what it’s good at doing! To install it on Fedora 20, you can run:

$ sudo yum install libguestfs-tools

It wasn’t available in Fedora 19, but after a lot of pain, I managed to build (mostly correct?) packages. I have posted them online if you are brave (or crazy?) enough to want them.

Using the right tool:

After building a few images, I realized that a shell script was the wrong tool, and that it was time for an upgrade. What was the right tool? GNU Make! After working on this for more hours than I’m ready to admit, I present to you, a lovingly crafted virtual machine base image (“box”) builder:

Makefile

The Makefile itself is quite compact. It uses a few shell scripts to do some of the customization, and builds a clean image in about ten minutes. To use it, just run make.

Customization:

At the moment, it builds x86_64, CentOS 6.5+ machines for vagrant-libvirt, but you can edit the Makefile to build a custom image of your choosing. I’ve gone out of my way to add an $(OUTPUT) variable to the Makefile so that your generated files get saved in /tmp/ or somewhere outside of your source tree.

Download the image:

If you’d like to download the image that I generated, it is being generously hosted by the Gluster community here. If you’re using the Vagrantfile from my Puppet-Gluster+Vagrant setup, then you don’t have to download it manually, this will happen automatically.

Open issues:

The biggest issue with the images is that SELinux gets disabled! You might be okay with this, but it’s actually quite unfortunate. It is disabled to avoid the SELinux relabelling that happens on first boot, as this overhead defeats the usefulness of a fast vagrant deployment. If you know of a way to fix this problem, please let me know!

Example output:

If you’d like to see this in action, but don’t want to run it yourself, here’s an example run:

$ date && time make && date
Mon Jan 20 10:57:35 EST 2014
Running templater...
Running virt-builder...
[   1.0] Downloading: http://libguestfs.org/download/builder/centos-6.xz
[   4.0] Planning how to build this image
[   4.0] Uncompressing
[  19.0] Resizing (using virt-resize) to expand the disk to 40.0G
[ 173.0] Opening the new disk
[ 181.0] Setting a random seed
[ 181.0] Setting root password
[ 181.0] Installing packages: screen vim-enhanced git wget file man tree nmap tcpdump htop lsof telnet mlocate bind-utils koan iftop yum-utils nc rsync nfs-utils sudo openssh-server openssh-clients
[ 212.0] Uploading: files/epel-release-6-8.noarch.rpm to /root/epel-release-6-8.noarch.rpm
[ 212.0] Uploading: files/puppetlabs-release-el-6.noarch.rpm to /root/puppetlabs-release-el-6.noarch.rpm
[ 212.0] Uploading: files/selinux to /etc/selinux/config
[ 212.0] Deleting: /.autorelabel
[ 212.0] Running: yum install -y /root/epel-release-6-8.noarch.rpm && rm -f /root/epel-release-6-8.noarch.rpm
[ 214.0] Running: yum install -y bash-completion moreutils
[ 235.0] Running: yum install -y /root/puppetlabs-release-el-6.noarch.rpm && rm -f /root/puppetlabs-release-el-6.noarch.rpm
[ 239.0] Running: yum install -y puppet
[ 254.0] Running: yum update -y
[ 375.0] Running: files/user.sh
[ 376.0] Running: files/ssh.sh
[ 376.0] Running: files/network.sh
[ 376.0] Running: files/cleanup.sh
[ 377.0] Finishing off
Output: /home/james/tmp/builder/gluster/builder.img
Output size: 40.0G
Output format: qcow2
Total usable space: 38.2G
Free space: 37.3G (97%)
Running convert...
Running tar...
./Vagrantfile
./metadata.json
./box.img

real	9m10.523s
user	2m23.282s
sys	0m37.109s
Mon Jan 20 11:06:46 EST 2014
$

If you have any other questions, please let me know!

Happy hacking,

James

PS: Be careful when writing Makefile‘s. They can be dangerous if used improperly, and in fact I once took out part of my lib/ directory by running one. Woops!

UPDATE: This technique now exists in it’s own repo here: https://github.com/purpleidea/vagrant-builder

Testing GlusterFS during “Glusterfest”

The GlusterFS community is having a “test day”. Puppet-Gluster+Vagrant is a great tool to help with this, and it has now been patched to support alpha, beta, qa, and rc releases! Because it was built so well (*cough*, shameless plug), it only took one patch.

Okay, first make sure that your Puppet-Gluster+Vagrant setup is working properly. I have only tested this on Fedora 20. Please read:

Automatically deploying GlusterFS with Puppet-Gluster+Vagrant!

to make sure you’re comfortable with the tools and infrastructure.

This weekend we’re testing 3.5.0 beta1. It turns out that the full rpm version for this is:

3.5.0-0.1.beta1.el6

You can figure out these strings yourself by browsing the folders in:

https://download.gluster.org/pub/gluster/glusterfs/qa-releases/

To test a specific version, use the --gluster-version argument that I added to the vagrant command. For this deployment, here is the list of commands that I used:

$ mkdir /tmp/vagrant/
$ cd /tmp/vagrant/
$ git clone --recursive https://github.com/purpleidea/puppet-gluster.git
$ cd vagrant/gluster/
$ vagrant up puppet
$ sudo -v && vagrant up --gluster-version='3.5.0-0.1.beta1.el6' --gluster-count=2 --no-parallel

As you can see, this is a standard vagrant deploy. I’ve decided to build two gluster hosts (--gluster-count=2) and I’m specifying the version string shown above. I’ve also decided to build in series (--no-parallel) because I think there might be some hidden race conditions, possibly in the vagrant-libvirt stack.

After about five minutes, the two hosts were built, and about six minutes after that, Puppet-Gluster had finished doing its magic. I had logged in to watch the progress, but if you were out getting a coffee, when you came back you could run:

$ gluster volume info

to see your newly created volume!

If you want to try a different version or host count, you don’t need to destroy the entire infrastructure. You can destroy the gluster annex hosts:

$ vagrant destroy annex{1..2}

and then run a new vagrant up command.

In addition, I’ve added a --gluster-firewall option. Currently it defaults to false because there’s a strange firewall bug blocking my VRRP (keepalived) setup. If you’d like to enable it and help me fix this bug, you can use:

--gluster-firewall=true

To make sure the firewall is off, you can use:

--gluster-firewall=false

In the future, I will change the default value to true, so specify it explicitly if you need a certain behaviour.

Happy hacking,

James