PostgreSQL Debian apt repository GnuPG key update
By Jon Jensen
October 15, 2013
The excellent PGDG (PostgreSQL Global Development Group) apt repositories provide current point releases of supported PostgreSQL versions for Debian and Ubuntu LTS Linux. If you’d like to use a newer version of PostgreSQL than ships with your Linux distribution, or need to use an older Postgres release, you should take a look at http://wiki.postgresql.org/wiki/Apt.
A minor housekeeping matter arose just a few days ago: The GnuPG key used to sign the PostgreSQL packages expired on October 13. During a run of apt-get update && apt-get upgrade that leads to errors such as those seen here:
Get:1 http://security.debian.org wheezy/updates Release.gpg [836 B]
Get:2 http://security.debian.org wheezy/updates Release [102 kB]
Get:3 http://apt.postgresql.org wheezy-pgdg Release.gpg [836 B]
Get:4 http://ftp.de.debian.org wheezy Release.gpg [1,672 B]
Get:5 http://apt.postgresql.org wheezy-pgdg Release [29.2 kB]
Get:6 http://ftp.de.debian.org wheezy-updates Release.gpg [836 B]
Get:7 http://ftp.de.debian.org wheezy Release [168 kB]
Err http://apt.postgresql.org wheezy-pgdg Release
Get:8 http://security.debian.org wheezy/updates/main Sources [61.2 kB]
Get:9 http://security.debian.org …debian postgres sysadmin
First Dance: a Gentle Introduction to Dancer.pm for Web Services
By Jeff Boes
October 7, 2013
I’ve been dabbling in Dancer (Version One, not so much Version Two). Our first opportunity to create a production-worthy Dancer application just rolled out with encouraging results, so I thought I would outline some things we tried, and things we learned. Don’t worry if you don’t know a thing about Dancer; I’ll educate you a little as we go along.
First, some background. This application was a re-host and rewrite of an existing application written in JavaScript and plain old CGI Perl scripts, returning either HTML or fairly simple JSON objects. Even the database it connected to was ancient DBM files. Those files were created by extracting data from the main website’s database, so that part was easy to replace—we just had to use the extraction queries (mostly) to connect directly.
We chose Dancer as the platform for this effort because of its purely Perl footprint, and its relatively easy deployment.
Since I didn’t really want to rewrite the front-end JavaScript code, I left that mostly as-is and concentrated on replacing the CGI scripts. The first step was to move all their code into a non-Dancer Perl module, which communicated with the outside world entirely in the form of …
dancer perl
Newest European Liquid Galaxy installation: Google Hamburg shop-in-shop
By Bianca Rodrigues
October 2, 2013
In September 2013, Google opened a store-in-store within the large electronics retailer Saturn in Hamburg. Dominating the visuals of the store is a large Liquid Galaxy on the back wall.
We partnered with system integrator Pixel Projects this time, and instead of our usual 7 screen display, worked the Liquid Galaxy into an unique 3x3 video wall array. The Liquid Galaxy shows Google Earth and will be showing Google Street View starting later this month, further highlighting the rich set of services offered by Google. It is also integrated with traditional video wall software configured by Pixel Projects such that it it can be switched to displaying Google services such as YouTube, Google Drive, Hangouts, and more. As always, the Liquid Galaxy is a huge customer draw. Customers who come through the store can explore any point on the globe while they browse the Google products.
End Point worked under the direction of the retail experience agency, Make Retail, to design a fully integrated experience. Once the unique configuration of the Liquid Galaxy was set, we sent along one of our top engineers, Matt Vollrath, to oversee the final hardware and software integration and …
clients google-earth visionport
Getting the Django Admin to sort modified columns
By Phineas Jensen
September 28, 2013
A lot of what I’ve worked on at End Point is Ovis, a program to keep track of information about our servers. This information includes current operating system, data center, which client owns or uses it, etc. Ovis is built entirely on the Django Admin, with the most important information displayed on the Servers list page.
A very important part of it is tracking server updates.
Knowing when and by who a server was last updated is nice to see, but to put it to good use, we needed to have a column that would show when it was last updated and who last updated it. We also wanted this column to have links to the relevant pages.
Django has a handy way of using functions to create a column based on data that is not part of the model being listed. The documentation for that is here. This is the code we are using:
def latest_update(self):
try:
object = self.update_set.latest()
if object:
return "<a href="%s">%s</a> by <a href="%s">%s</a>" % (
'/admin/ovisapp/update/%s' % object.id,
object.when_updated.date(),
'/admin/auth/user/%s' % object …django python
Comparing installed RPMs on two servers
By Jon Jensen
September 27, 2013
Sometimes I’m called on to deal with a problem that shows up only on one of two or more servers that are supposed to be configured identically, or nearly identically. One of the first things I do is run rpm -qa | sort on each machine and diff the output to see which RPM packages may be missing on one or the other server. I’ve never bothered to package this functionality up into a script because it’s so simple.
To exclude minor version differences, you need to specify a custom rpm --queryformat that leaves the version number off.
To understand what you’re seeing when it appears that some package is different but seems the same, you’re often looking at multiple architectures of packages (e.g. i386 and x86_64) which RPM doesn’t show in its default query format.
Finally, to turn the diff output into a list of RPMs to install via yum, I usually do some combination of grep and sed to pick out the RPMs I need.
After all that the process isn’t entirely simple anymore, and I recently decided it was easier to script it than explain it all to someone else. I first looked around to see what scripts others have come up with, since this is certainly not a new need. I found the blog post “Compare …
hosting redhat sysadmin
A Solution to the Most Common Rails Authentication Problem
By Tim Case
September 24, 2013
Q: What’s one of the most common authentication related mistakes?
A: Forgetting to write the code that triggers authentication.
Q: What can we do about it?
A: Make it easier to test authentication.
The most common authentication problem that probably affects every Rails app is forgetting or overlooking the implementation of the authentication. In Rails, this generally means forgetting to add a controller before filter to verify the user is authenticated for actions that should be protected. Let me be the first to admit that I’m guilty of doing this myself but I’ve noticed it occurring in all Rails apps that I’ve worked on.
Having seen this problem, committed it myself, and being bothered by it, I’ve come up with a small solution that is my humble attempt to solve the problem by making it easier to track what is being authenticated and what isn’t. Before I show the solution I want to divulge that the current implementation has some shortcomings which I will explain towards the end of the article, but I feel it’s still a worthwhile solution in the form of the “good outweighs the bad”.
The solution is to provide helpers that make it easy to unit test the authentication of …
ruby rails
eCommerce Innovation Conference 2013
By Richard Templet
September 20, 2013
The eCommerce Innovation Conference 2013 is a new conference being held in Hancock, New York, between October 8th and 11th. The conference aims to discuss everything ecommerce with a focus on Perl-based solutions including Dancer and Interchange. It isn’t geared directly to any one specific type of person unlike most conferences. The current speakers list include in-house ecommerce software developers, consultants, sales managers, project managers, and marketing experts. The talk topics range from customer relationship management to template engines for Perl.
Mark Johnson and I are both going to be speaking at the conference. Also there will be Mike Heins, creator of Interchange, and Stefan Hornburg, longtime Interchange development group “team captain”.
Mark is going to be discussing full page caching in Interchange 5. This is becoming a more frequent request from our larger customers. They want to be able to do full page caching to allow the web browser and a caching proxy server alone to handle most requests leaving Interchange and the database open to handle more shopping-based requests like add to cart or checkout. This is a commonly-used architecture in many application …
camps community conference dancer ecommerce interchange perl
Monitorama, Berlin, EU - Day 2 and final considerations
By Emanuele “Lele” Calò
September 20, 2013
Moving toward the end of IT conferences your expectations sometime gets lower cause the speakers are tired and so are the attendees. You kind of expect things to get quieter but this wasn’t the case with Monitorama EU 2013.
On this second day I found that all of the talks were as interesting, entertaining and inspiring as the ones on the first day.
I enjoyed all the talks proposed today but I got very inspired by the ones from Jeff Weinstein which talked about how you can use data collected for metrics and monitoring to improve the whole company. I also appreciated the speech from Gareth Rushgrove which highlighted how security is actually still underrated in IT companies and how/why you should try to integrate monitoring with security auditing tools.
I’ve been asked a few times, during the day and the evening, which was my opinion about the conference and the answer was always “absolutely positive!”. I always add that though I don’t expect to see any rocket science in these conferences I kind of suppose that I’ll get a lot of hints, ideas and tips which are a wonderful trampoline for new personal or work-related projects. That is exactly what I got.
The other aspect you …
conference monitoring nagios