linux

Adopt the cloud, kill your IT career

~ Matt Smith ~ Leave a comment

http://www.infoworld.com/print/195144

…You might be eager to relinquish responsibility of a cranky infrastructure component and push the headaches to a cloud vendor, but in reality you aren’t doing that at all. Instead, you’re adding another avenue for the blame to follow. The end result of a catastrophic failure or data loss event is exactly the same whether you own the service or contract it out. The difference is you can’t do anything about it directly. You jump out of the plane and hope that whoever packed your parachute knew what he or she was doing….

Using the UITS SSH Gateway

~ Matt Smith ~ Leave a comment

Adding the following to your ~/.ssh/config will cause all SSH access to servers named *.uits.uconn.edu to hop through ssh.uits.uconn.edu, authenticating as your NetID.  Note that if you have kinit’d as <NETID>/admin, or if you have copied your public SSH key to ssh.uits.uconn.edu and are using ssh-agent, this will be transparent.

Host ssh.uits.uconn.edu
    ProxyCommand none

Host *.uits.uconn.edu
    ProxyCommand ssh -A <NETID>@ssh.uits.uconn.edu exec nc %h %p

Cross-posting …

~ Matt Smith ~ Leave a comment

Took me 15 minutes of searching and trying, but I eventually figured out how to get all posts tagged “linux” from my personal blog to be cross-posted here.

Check out the FeedWordPress plugin for WordPress — simply supply the remote RSS URL, and FeedWordPress will import posts directly into your WordPress site.

 

UCARP and Squeeze

~ Matt Smith ~ 3 Comments

IP fault tolerance on Debian Squeeze couldn’t be easier than with UCARP!:

  • Install UCARP on all nodes: 
    apt-get install ucarp
  • Edit /etc/network/interfaces on all nodes, replacing <CLUSTER IP> and <PASSWORD> as appropriate: 
    iface eth0 inet static
...
ucarp-vid 3
ucarp-vip <CLUSTER IP>
ucarp-password <PASSWORD>
ucarp-xparam -n
iface eth0:ucarp inet static
address <CLUSTER IP>
netmask 255.255.255.255
  • Reboot, and you’re done!  <CLUSTER IP> will now be available from one of the nodes in your cluster at all times!

A few notes:

  • All nodes in your UCARP cluster must be in the same subnet, and the shared cluster IP must also be in the same subnet.
  • UCARP does not do cluster resource management for you, but it does provide hooks.  You will need to write some scripts to handle unmounting/mounting of shared storage, etc.
  • UCARP does not detect service failures, only whole-host (or IP stack) failures.  But if you can detect the failure, simply send SIGUSR2 to the ucarp process to force into passive mode, forcing another node to become master.
All-in-all, about as simple and sufficient as one can get!

GitHub

~ Matt Smith ~ Leave a comment

Whelp, I’ve gone and done it — my first Git project, hosted at GitHub.  I’ve used Subversion quite a bit, but this is my first foray into the world of DVCS.

Aside from the solid technology, the benefits of DVCS, the functionality of the GitHub platform … the GitHub Bootcamp and Help pages really sold me.  The folks at GitHub really know how to ease the transition for new members.  Great job, Hubbernauts!

Convert Dropbox’s Ubuntu package for Squeeze

~ Matt Smith

The Dropbox Ubuntu package almost works on Debian Squeeze … except for one dependency with a numbering scheme that differs between Ubuntu and Debian.  Here is a quick script that extracts the package, corrects the one dependency in DEBIAN/control, and repackages, leaving a new .deb suitable for Squeeze.

convertDropbox4Squeeze:

#!/bin/sh
if [ $# -ne 1 ]; then
	echo "Usage: $0" 'nautilus-dropbox_$version_$arch.deb'
	exit 1
fi
DIR=`mktemp --directory`
mkdir -p $DIR/DEBIAN
dpkg-deb -x $1 $DIR/
dpkg-deb -e $1 $DIR/DEBIAN/
sed -i s/'libnautilus-extension1 (>= 1:2.22.2)'/'libnautilus-extension1 (>= 2.22.2)'/ ${DIR}/DEBIAN/control
dpkg-deb -b $DIR  ${1%.*}_squeeze.deb
rm -rf $DIR

Just download the .deb from the Dropbox site, then run

./convertDropbox4Squeeze nautilus_dropbox.......deb

And then just install the newly created nautilus_dropbx….squeeze.deb .

Convert Dropbox’s Ubuntu package for Squeeze

~ Matt Smith ~ 1 Comment

The Dropbox Ubuntu package almost works on Debian Squeeze … except for one dependency with a numbering scheme that differs between Ubuntu and Debian.  Here is a quick script that extracts the package, corrects the one dependency in DEBIAN/control, and repackages, leaving a new .deb suitable for Squeeze.

convertDropbox4Squeeze:

#!/bin/sh
if [ $# -ne 1 ]; then
	echo "Usage: $0" 'nautilus-dropbox_$version_$arch.deb'
	exit 1
fi
DIR=`mktemp --directory`
mkdir -p $DIR/DEBIAN
dpkg-deb -x $1 $DIR/
dpkg-deb -e $1 $DIR/DEBIAN/
sed -i s/'libnautilus-extension1 (>= 1:2.22.2)'/'libnautilus-extension1 (>= 2.22.2)'/ ${DIR}/DEBIAN/control
dpkg-deb -b $DIR  ${1%.*}_squeeze.deb
rm -rf $DIR

Just download the .deb from the Dropbox site, then run

./convertDropbox4Squeeze nautilus_dropbox.......deb

And then just install the newly created nautilus_dropbx….squeeze.deb .