Top Tech Tips

Netbeans SVN over SSHFS

2009-12-03T03:34:00.000-08:00

Over the past couple of days, I have been struggling with trying to get the Netbeans Subversion Plugin to work over sshfs.

Simply put, the working directory is on a remote system. I mount the working directory using SSHFS and open the project in Netbeans. The plugin works fine until you wrote to the repository via an update/revert/commit command. The error received is a derivative of some "Operation not Permitted".

The problem was some sort of symlink issue over sshfs.

I literally found a "workaround" of the following form:

use the "-o workaround=rename" parameter to sshfs and all is now working!

thanks to: http://ubuntuforums.org/showthread.php?t=1065308

Annoying "Call Forwarding Active" popup message on GSM phone!

2009-11-04T04:53:00.000-08:00

I recently found a way to get rid of that annoying message that pops up when you place an outgoing call on a GSM mobile phone.

The message that appears is "Call Forwarding Active", which serves no purpose whatsoever!

To remove it, simply dial the following GSM code:

##002#

Wallah! No more annoying popup!

Array Shuffle in Rails

2009-11-02T05:00:00.000-08:00

Here is a nice snippet of code which you can put into a file called Array.rb in the config/initializers directory of your rails apps. It adds a function to the array class to randomly shuffle the array elements.

class Array
# Shuffle the array
def shuffle!
n = length
for i in 0...n
r = Kernel.rand(n-i)+i
self[r], self[i] = self[i], self[r]
end
self
end

# Return a shuffled copy of the array
def shuffle
dup.shuffle!
end
end

Putting JavaScript Bookmarks to Work

2009-04-03T05:02:00.000-07:00

Putting JavaScript Bookmarks to Work — Hypertext is wonderful. It allows the Webmaster to link from any page to millions of other computers all over the world. Unfortunately, the Web pages you find will only have the links that were placed by the Webmasters. What if you want more information about a word or a phrase on a page and there's no link?

Here is how you do it: http://java.sys-con.com/node/36105

Wireless Networking without a Router

2009-04-02T05:49:00.001-07:00

Little did I know that you can set up an "ad-hoc" wireless network between a group of windows machines, without the need, for a router!

Very nice.

Here is a guide, on Microsofts very own site, on how to go about it:

http://www.microsoft.com/windowsxp/using/networking/expert/bowman_02april08.mspx

Fiveruns For Rails Monitoring

2009-03-31T20:24:00.001-07:00

Been using brightbox hosting for the last couple of months now to host my rails applications and today found out about one of the cool features I had overlooked.

Fiveruns management is a tool for profiling your server and the rails applications that run on it. A screencast about fiveruns can be found here:

http://www.fiveruns.com/products/manage/screencast

When you sign up to a 512mb brightbox, you receive a free fiveruns manage account. The following is a guide on how to set up fiveruns on your brightbox.

Setting Up RM-Manage - Brightbox Wiki

Linking Google Analytics to your Adsense accounts! Thank you Google

2009-03-30T17:30:00.001-07:00

Thank you once again Google, yet another gem of a tool!

AdSense Reporting in Google Analytics

Wordpress Theme Customization & Design - Creating Sidebars

2009-03-23T04:24:00.001-07:00

I have been messing around with wordpress as a medium for my new site www.leefarrell.com

I found a nice article which explains how you can set up custom sidebars in order to put those neat little plugins wherever you like, without being restricted to what your selected wordpress theme allows.

Check it out here:

Wordpress Theme Customization & Design - Creating Sidebars

Manually Changing your Wordpress Theme

2009-03-23T04:07:00.001-07:00

Today, I got myself in a bit of a muddle.

I accidentally put some weird unicode characters into one of my wordpress templates and caused the wp-admin functionality to stop working, along with my actual blog.

I tried to manually remove the bad characters but found that I had not got direct write access to the file I had been editing through the wp-admin interface. Subsequently, I was stuck, unless there was a way to manually switch my current wordpress template back to the default one which i knew funtioned correctly.

Low and behold, I found this article:

How to manually change your Wordpress theme | jasonlittle.ca

Software Estimation

2009-03-19T23:33:00.001-07:00

I find that one of the hardest things to do is to estimate the time it will take to make a piece of software.

There are numerous articles and methodologies out there to aid the process, but I think wisdom and experience are the all out winners in this game. Obviously the more software you have made in the past, the easier it is for you to gauge how long it will take you in the future due to the fact that you have most likely developed something similar beforehand.

Here is one such article that addresses the overall issue of estimating a large project with a whole software team

http://woork.blogspot.com/2009/02/simple-process-to-estimate-time-and.html

If the above link ceases to work, try the following:

http://backupurl.com/z2qmna

Also, I have copied a version of the google doc spreadsheet used in the example.

It can be found here:

http://spreadsheets.google.com/ccc?key=petUaHRM4FuL2z2BIPeCqVg

SSH Tunnel + SOCKS Proxy Forwarding = Secure Browsing

2009-03-18T20:43:00.003-07:00

I found a nice article a while back which allows me to browse through a secure proxy.

I have referenced it a few times since then and thought it might be worth featuring it in my blog.

I will provide a link to the original article and also copy the text below, as we all know that links only last so long!

Here is the original article in all its glory:

(taken from http://ubuntu.wordpress.com/2006/12/08/ssh-tunnel-socks-proxy-forwarding-secure-browsing)

When you are at the coffee shop, or at a conference, and you are not sure that you want to send all your data over the wi-fi network in plaintext, you want a secure tunnel to browse. This happened to me recently and I stumbled across a neat feature of openssh (the ssh client on everyone’s computer). The wonders of ssh never cease to amaze me!

You can use the “-D” flag of openssh to create a SOCKS proxy.

The command first:
$ssh -D 9999 username@ip-address-of-ssh-server

This of course connects you to the server specified by “ip-address-of-ssh-server”. Needless to say, you (username) must have an ssh account on the server. In addition, this will create a SOCKS proxy on port “9999″ of your computer. This is a tunnel to the server. Now all you have to do is set the preference in Firefox to use a SOCKS proxy. The proxy is, of course, “localhost”, with the port 9999.

Now when you browse, all the connections you make to websites will seem to originate from the server to which you SSH-ed. In addition, all outgoing and incoming data for the browsing session will be encrypted since it passes through the SSH connection.

Other applications (like email clients) may also support SOCKS proxies. If any of them, you can look into using proxychains(there’s an Ubuntu package).

You can misuse this technology to circumvent paranoid browsing firewalls, even to pretend you are wherever your ssh server is located - so you can work around country-based blocks etc. I use it for the very unromantic reason that I don’t want some aspiring cracker to sneak up on me when I am in public.

Updates:

Kees Cook tells us how to tunnel DNS lookups, so snoopy folks can’t even figure out what your are browsing, and the evil ones can’t DNS-phish you
Don McArthur points out his excellent article that addresses the same issue
verevi says the FoxyProxy extension will make things easier for you on the Firefox side of things

Thanks a lot for the tips and pointers, folks.

Website Wording (Copy)

2009-03-18T19:36:00.000-07:00

Although it is common that web developers end up writing all the text for a website they are working on, generally it should be done by somebody who has not been knee deep in the html and css of the site.

We, as developers, happen to think that everybody is just as intelligent as us when it comes to understanding how things on our site work. We overlook the fact that even the most simplest things on a site can be made complicated, given the right users.

Website copy (The wording on the site) should be written in a way that it lets users know exactly what is going on without getting too technical, and at the same time, provide some friendliness to make the user feel like he/she can use the tools that the site provides.

I think one of the best examples of website copy comes from google. Just recently, I tried setting up my blog on FeedBurner, when i went to view the statistics for my blog I encountered a page which had a simple modal panel in the middle of the page with the words:

"Your feed is so new, we’re still playing with the bubble wrap"

"Check back soon for a full dose of stats"

Although this does not tell the user how to use the site, it serves as a simple example of how you can incorporate even a little humour into your copy in order to boost a users willingness to continue to use your site.

Another prime example of really well written copy is on a site that I have been working on for the past 6 months. www.edenbee.com is a social networking site with a green concept. I did not write the copy for this but I have seen it all and it is quirky and interesting. Go and check it out, you may pick up some ideas!

Testing Web Development in IE on Ubuntu

2009-03-16T05:14:00.000-07:00

Among a web developers worst enemies are cross browser issues.

When developing html and css for an application, one must consider the variety of browsers that users will access the application through.

I found this to be a nightmare. Most developers generally stick to the three most popular browsers: IE, Firefox and Safari.

Even then, the process of designing a layout to work consistently across the three can be nightmarish.

One tool i have found to aid this painfull process is the IETab addon for firefox, which, allows you to render the page using the Internet Explorer rendering engine, without having to actually switch browsers. You can download this plugin from the firefox website. Although it will not make the design process easier, it will allow you to spot inconsistencies more easily.

Another issue, us linux developers have is that Internet Explorer is not packaged with any of the distros. Not to worry, there is an application called ies4linux which does exactly what it says on the tin. It uses wine to allow you to run Internet Explorer from within your linux distribution.

A tutorial for Ubuntu can be found here: http://www.psychocats.net/ubuntu/ies4linux

I hope that, one day, a standard will emerge for a rendering engine. One that is 100% css compliant. It will make our jobs so much easier!

Assembla Project Management

2009-03-12T21:59:00.000-07:00

For those of you developers out there, or even project managers of any sort for that matter.

There is an online project management tool called assembla where you can organise a kind of "to-do" list for you projects.

I find this tool extremely useful for a couple of reasons:

It breaks a project up into smaller, more manageable pieces
It allows a whole team to collaborate without being together at once (great for developing from home :D)
It allows you to set the times it will take to complete the tasks
It allows you to set milestones in your project, by which, certain tasks must be met.

The biggest thing for me, is that it allows me to feel like I am getting some work done. When I used to look at my to-do list in the morning, it looked totally unmanageable, but now, looking at smaller sized chunks of work, it is a lot easier for me to get my head around my daily tasks.

Assembla is free to use with the option of a premium account.

I recommend anybody who is in the same boat as myself to go and check it out

www.assembla.com

Monit for Ferret Server

2009-03-11T16:23:00.000-07:00

Been having a bit of trouble lately with ferret_server that ships with the open source lovdbyless framework for rails.

It seems that ferret server decides on occasion, to stop responding.

Monit to the rescue...

For those of you who have not used Monit, it is a process watching application that will watch over, and restart, any process you configure in its config files.

To use it with ferret server i simply added the file ferret_server.monitrc into /etc/monit/conf.d with the following snippet of code (with my paths changed, of course)

# monit configuration snippet to watch the Ferret DRb server shipped with
# acts_as_ferret
check process ferret with pidfile /path/to/ferret.pid

# username is the user the drb server should be running as (It's good practice
# to run such services as a non-privileged user)
start program = "/bin/su -c 'cd /path/to/your/app/current/ && RAILS_ENV=production script/ferret_server start' username"
stop program = "/bin/su -c 'cd /path/to/your/app/current/ && RAILS_ENV=production script/ferret_server stop' username"

# cpu usage boundaries
if cpu > 60% for 2 cycles then alert
if cpu > 90% for 5 cycles then restart

# memory usage varies with index size and usage scenarios, so check how
# much memory your DRb server uses up usually and add some spare to that
# before enabling this rule:
# if totalmem > 50.0 MB for 5 cycles then restart

# adjust port numbers according to your setup:
if failed port 9010 then alert
if failed port 9010 for 2 cycles then restart
group ferret

thanks to http://www.jkraemer.net for this.

Apache Virtual Host Enable/Disable

2009-03-10T17:35:00.000-07:00

There is a cool feature i learned about today in apache where you can enable/disable sites defined in your VirtualHost blocks of your http.conf file.

Simply use the following command on you server to disable a site:

sudo a2dissite appname

(appname is whatever identified you used to describe your app)

Then you must reload your apache server to take note of the changes:

sudo /etc/init.d/apache2 reload

and then to re-enable later:

sudo a2ensite rails-appname
sudo /etc/init.d/apache2 reload

Its as simple as that.

I have used it to disable a site on one of my hosting accounts as one of my the was overloaded.

thanks to John Leach from brightbox hosting for this little tip.

I use brightbox for my rails hosting. Its a very nice little company who are always ready to help out and their customer query response time is extremely fast. You can get a rails app going in no time with their gem package "brightbox" using capistrano for deployment.

See Brightbox here

Active Resource Connection Debugging

2009-03-04T00:13:00.000-08:00

Active resource uses hte Net:HTTP package to make its connections. If you want to debug
these connections you can override the connection class and add in a line to debug
to stderr as follows.

In your rails project put this in a file called connection.rb in the config/initializers directory and
you should see a dump of all your interactions with ActiveResource::Connection.

class ActiveResource::Connection
 # Creates new Net::HTTP instance for communication with
 # remote service and resources.
 def http
   http = Net::HTTP.new(@site.host, @site.port)
   http.use_ssl = @site.is_a?(URI::HTTPS)
   http.verify_mode = OpenSSL::SSL::VERIFY_NONE if http.use_ssl
   http.read_timeout = @timeout if @timeout
   #Here's the addition that allows you to see the output
   http.set_debug_output $stderr
   return http
 end
end

Ubuntu Application Launcher Icons

2009-03-03T19:57:00.000-08:00

Ever had trouble trying to get the right icon for your application launcher in ubuntu?

Its a pain in the ass, when you navigate to a directory with images in which to choose a custom icon for your launcher, low and behold, no images appear.

The average user will think to self, "Oh, my image must be of a certain format". This leads to one trying to do all sorts of image type conversions to get their image to svg format. Hmmm...

If you type the location of the directory which holds your target image into the actual text box where you select your image, it pin points your image, where you solve all your problems and enjoy your neat little graphic sitting there on top of your custom launcher.

Its not rocket science, just a stupid little overseen bug!

thanks to http://forums.opensuse.org/archives/sf-archives/archives-software/347262-convert-png-svg.html#post1610305