GIS Visualizations on the Liquid Galaxy
By Dave Jenkins
March 25, 2014
The Liquid Galaxy presents an incredible opportunity to view Google Earth and Google Street View, but did you know that the platform is also amaza-crazy good at visualizing GIS data?
Geographic Information Systems are concerned with collecting, storing, and manipulating data sets that include geographic coordinates, and with displaying this raw and analyzed data on maps. In the 2D world this usually involves colored pencils or highlighted polygons. As computing power advances many GIS consultancies have extended the GIS visualization methods to see complex 3D visualizations on digital maps. The Liquid Galaxy takes this concept forward another step: see your data across an immense landscape of pixels in a geometrically-adjusted immersive world.
The Liquid Galaxy has separate instances of Google Earth running on each screen. In a standard Liquid Galaxy this means that each 1080x1920 screen is getting a full resolution image. It also means that the viewing angle for each screen matches the physical angle of that screen. Together, those elements can show geographical information at an incredible scale and resolution.
End Point has developed skills and methods to take GIS data sets …
visualization gis visionport
Mountain West Ruby Conference, Day 1
By Mike Farmer
March 25, 2014
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| MWRC Notes |
It’s that magical time of year that I always look forward to, March. Why March? Because that’s when Mike Moore organizes and puts on the famed Mountain West Ruby Conference in Salt Lake City, Utah. This conference is always a personal pleasure for me due to the number of incredible people I get to meet and associate with there. This year was no exception in that regard. It was simply fantastic to meet up with old friends and catch up on all their latest and greatest projects and ideas.
In writing a summary of day 1 here, I’d like to focus on just three talks that you will definitely want to go watch over on confreaks as soon as they are up. All the talks were great, but these three were exceptional and you won’t want to miss them.
A Magical Gathering
The opening keynote started off with a bang of entertainment and just plain geeking out with Aaron Patterson. Aaron holds the peculiar position of being on both Ruby core and Rails core teams. Aaron’s code is probably used by more people than just about anyone in the Ruby community. Everyone that knows and loves Ruby and Ruby on Rails is indebted to this genius and generous coder. But Aaron is more than just a coder. …
conference ruby rails
Proxy Nginx ports using a regular expression
By Brian Gadoury
March 19, 2014
I’m working on a big Rails project for Phenoms Fantasy Sports that uses the ActiveMerchant gem to handle Dwolla payments. One of the developers, Patrick, ran into an issue where his code wasn’t receiving the expected postback from the Dwolla gateway. His code looked right, the Dwolla account UI showed the sandbox transactions, but we never saw any evidence of the postback hitting our development server.
Patrick’s theory was that Dwolla was stripping the port number off the postback URL he was sending with the request. We tested that theory by using the RequestBin.com service for the postback URL, and it showed Dwolla making the postback successfully. Next, we needed to verify that Dwolla could hit our development server on port 80.
I started Nginx on port 80 of our dev server and Patrick fired his Dwolla transaction test again. The expected POST requests hit the Nginx logfile. Suspicions confirmed. It looked like we would just have to work around the Dwolla weirdness by proxying port 80 to the port that Patrick’s development instance was running on. Then we’d need a way to make that work for the other developers’ instances on the dev. server, as well.
Proxying a single port to …
camps nginx rails
Significant Whitespace in an Interchange UserTag
By David Christensen
March 18, 2014
Here’s a quick issue I ran into with an Interchange UserTag definition; I’d made some changes to a custom UserTag, but upon restarting the Interchange daemon, I ended up with a message like the following:
UserTag 'foo_user_tag' code is not a subroutine reference
This was odd, as I’d verified via perl -cw that the code in the UserTag itself was valid. After hunting through the changes, I noticed that the UserTag definition file was itself in DOS line-ending mode, but the changes I’d made were in normal Unix line-ending mode. This was apparently sufficient reason to confuse the UserTag parser.
Sure enough, changing all line endings in the file to match resulted in the successful use of the UserTag. For what it’s worth, it did not matter whether the line endings in the file were Unix or DOS, so long as it was consistent within the file itself.
interchange
Scripting ssh master connections
By Josh Williams
March 17, 2014
At End Point, security is a top priority. We just phased out the last of the 1024-bit keys for all of our employees—those of us in ops roles that have keys lots of places had done so a long while back. Similarly, since we’ll tend to have several sessions open for a long while, a number of us will use ssh-agent’s -c (confirm) option. That forces a prompt for confirmation of each request the agent gets. It can get a little annoying (especially since it takes the focus over to one monitor, even if I’m working on the other) but it combats SSH socket hijacking when we have the agent forwarded to remote servers.
Working on server migrations is where it gets really annoying. I like to write little repeatable scripts that I can tweak and re-run as needed. They’re usually simple little things, starting with a bunch of rsync’s or pipe-over-ssh’s for pg_dump or any other data we need to move across. With any more than a couple of those ssh connections in there, repeatedly hitting the confirm button gets irritating fast. And if a large transfer takes a while, I’ll go off to do something else, later getting an unexpected confirmation box when I’m not thinking about the running script. …
ssh sysadmin
Provisioning a Development Environment with Packer, Part 2
By Mike Farmer
March 14, 2014
In my previous post on provisioning a development environment with Packer I walked through getting a server setup with an operating system installed. This post will be focused setting up Ansible so that I can setup my development environment just the way I like it. Packer supports many different methods for provisioning. After playing with some of them, I decided that Ansible was a good mix of simplicity and functionality.
A Packer provisioner is simply a configuration template that is added to the json configuration file. The “provisioners” section of the configuration file takes an array of json objects which means that you aren’t stuck with just one kind of provisioner. For example, you could run some shell scripts using the shell provisioner, then upload some files using the File Uploads provisioner, followed by your devops tool of choice (puppet, salt, chef, or ansible). You can even roll-your-own provisioner if desired. Here’s an example provisioner setup for the shell provisioner:
{
"variables": {...},
"builders" : [...],
"provisioners" [
{
"type": "shell",
"inline": [ "echo foo" ]
}
]
}
Sudo …
ansible devops environment tools
Setup Rails Environment with PostgreSQL on Apple Mac OS X
By Selvakumar Arumugam
March 14, 2014
Setting up Rails on Mac OS X to have a Rails application is a tedious process. It’s a kind of road block for newbies. Here I have listed the steps to have Rails application running with a PostgreSQL database on the Mac OS X.
1. Rails
Before installing Rails, We need couple of things installed on Mac OS X.
Ruby
Luckily Mac OS X comes with preinstalled Ruby.
$ ruby -v
ruby 2.0.0p247 (2013-06-27 revision 41674) [universal.x86_64-darwin13]
Xcode and Command Line Tools
Install Xcode from Mac Store. Xcode contains some system libraries which are required for Rails.
To install Command Line Tools, Open Xcode -> Xcode(menu bar) -> Preferences -> Downloads -> Install ‘Command Line Tools’
Homebrew
Homebrew helps to install gems with ‘gem’ and its dependencies with help of brew. Homebrew makes our life easier by handling dependencies for us during installation.
$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
Note:– Xcode already comes bundled with gcc. But install gcc using homebrew if you face any gcc problems while installing Rails.
$ brew tap homebrew/dupes
$ brew install apple-gcc42
$ sudo ln -s /usr/local/bin/gcc-4.2 …mac postgres rails tls
Restrict IMAP account access to one (or more) IP address
By Emanuele “Lele” Calò
March 13, 2014
If you’re in need of some extra layer of security on your mail server and know in advance who is going to access your IMAP account and from where (meaning which IP), then the following trick could be the perfect solution for you.
In order to use this feature you’ll have to use Dovecot 2.x+ and then just add a comma separated list of addresses/subnets to the last field of your dovecot passwd auth file:
user:{plain}password::::::allow_nets=192.168.0.0/24,10.0.0.1,2001:abcd:abcd::0:0/80
After a quick reload Dovecot will start to enforce the specified new settings.
An additional neat aspect is that from an attacker perspective the given error will always be the same one got from a “wrong password” attempt, making basically impossible to discover this further protection.
Stay safe out there!
email iptables security