Category Archives: Open Source
Howto pdnsd on redhat/centos from Source
What is pdnsd
pdnsd is a cache only name server can be used independently or alongside your authoritative name server for faster name lookup.
pdnsd does not aim to be a complete name server implementation, such as the BIND. It is optimized for caching, and you can only specify a small subset of all dns record types pdnsd knows in your local “zone” definitions. This of course reduces the code size drastically, and such the memory footprint. There are some features especially interesting for dialin networks, ordinary (non-server) internet hosts and computers that are often not connected to to their network, e.g. notebooks (I originally wrote this program for use with my notebook). These features are:
- permanent disk cache (useful for frequent power-offs/reboots)
- usually smaller memory footprint (depends on cache size) (see next question)
- better control about timeouts (also to prevent hangs)
- better control over the cache
- better run-time control of the cached records
Moodle Demo site on Moodle 2.4
http://demo.xeois.com/moodle is setup to demonstrate a sample Moodle Course. The goal is to provide end user experience of Moodle in the role of student.
This demonstration includes, video, quiz, lesson, wiki, assignment, choice, survey, html content, Moodle book and more.
This site is also accepting course from from teachers who would like to showcase their courses for free.
For your demo experience at http://demo.xeois.com/moodle you may use one of these Demo Login password
| Demo login: moodledemo01 Password: Moodledemo*1 |
Demo login: moodledemo02 Password: Moodledemo*2 |
Demo login: moodledemo03 Password: Moodledemo*3 |
you may also create your own account in that site.
for teachers access, to contribute a course you may email to info@xeois.com
Hope you find this sample Moodle course useful, your feedback is appreciated.
Moodle changes across 2.3 to 2.4
As a follow up to my earlier blog, i wanted to publish new features of Moodle from 2.3 to 2.4, was released on December 2012. Many of the bugs from previous Moodle release has been fixed. Check the list of bugs fixed in Moodle 2.4.
Requirements for Moodle 2.4 installation
- Recommended browsers for moodle 2.4: Firefox 4, Internet Explorer 8 (IE 10 required for drag and drop of files from outside the browser into Moodle), Safari 5, Google Chrome 11
- Moodle upgrade: If you want to upgrade to Moodle 2.4, you must be running Moodle 2.2 or above. If you have a Moodle version lower than Moodle 2.2, you must upgrade to 2.2 first
- Minimum DB versions: Postgres 8.3, MySQL 5.1.33, MSSQL 2005 or Oracle 10.2
- Minimum PHP version: PHP 5.3.2
Performance improvement
Moodle 2.4 was introduced some major performance improvement which includes better indexing in PostgreSQL, improved statistics performance, data base meta caching, question related caching and more. All these resulted in over all performance improvement.
Plugin updating from within Moodle
New Moodle plugin interface now support update check as well as updates from the web interface as well as update the plugins from the web interface.
Course format plugins
Course formats can now provide their own settings for courses and sections, and developers can also have a lot more control of all the pages in a course.
Themes
- Support for HTML5 themes
- Improved compatibility with Internet Explorer 8-10.
- The default icons used for activities and editing actions have been updated for the first time since Moodle 1.0. This is a major look and feel improvement. Now they a little bigger and more colourful. These icons are SVG format and support full scaling on all devices.
- SimpleYUI enables similar coding style to JQuery, it is intended especially for theme designers.
Other improvements:
- Improved TinyMCE editor integration, Support for fully configurable add-on plugins extending standard, customizable toolbar, and built in browser spell check.
- Improved enrollment plugin, cohort synchronization with course group also fixes on the plugin.
- Integration with external calendar: You can now stream your external calendars (such as Google Calendar, or a calendar from another Moodle site) into Moodle’s calendar via the iCal standard.
- Assignment enhancements
- Workshop module enhancements
Security issues
All security issues that were fixed in 2.3.x and 2.2.x were also fixed in 2.4.
to read the full list of changes in Moodle 2.3 to 2.4 follow this link
Reference:
docs.moodle.org/dev/Moodle_2.4_release_notes
Content control software/ Web Content filtering using SquidGuard for enterprise network
Content filtering for enterprise network or educational institution can be a mandatory requirement in many institutions/organizations. Besides filtering web content by category, content control/filtering software can also helps us to filter out malware and virus sites, unwanted advertisements etc. Finding the right product and making it work for your organization can be a challenge. Click to find a list of content control software. When I first tried to implement content filtering system in my organization, the biggest challenge was to find the right product and get a demo running to check the integration aspects. After spending significant amount of time to identify a content filtering system that best fits my organization I did not get enough support from the local vendors. So later one decided to go with Squid Proxy with SquidGuard (some thing I used before). This works out very well for me. Besides being a little heavy on administration side, I have not much to complain about. This content filter can sit on the network as a proxy server and filter all web traffic as per the organization policy.
Educational institutors in many part of the world are bound by the law to protect children from inappropriate Internet contents. In business organizations or organizations of any type, Internet resources can be filtered for unwanted advertisements, malware, virus, pornography sites etc. Web content filtering or content control software is a smart way to address these issues and help enforce organizations policy and protect the network and its users.
Some of the categories that can be used to guide browsing behaviors are following
Advertisements, automobile, dating, education, gamble, hobby, isp, models, podcasts, recreation, ringtones, shopping, updatesites, weapons, webtv, aggressive, chat, downloads, finance, homestyle, jobsearch, movies, politics, redirector, science, socialnetwork, urlshortener, webmail, alcohol, drugs, fortunetelling, government, hospitals, library, music, pornography, religion, searchengines, spyware, violence, webphone, anonymous vpn, hacking, imagehosting, military, news, radio, tv, remotecontrol, sex, tracker, warez, webradio and more. These lists can be used to allow or disallow certain category of sites
SquidGuard implementation for enterprise network
SquidGuard is a content filtering tool used in enterprise network to control/filter sites that end users/hosts can access.
SquidGuard is built to work as a plug-in for squid. It uses black lists and url redirection technology to make this content filter work.
There are many free/paid black lists available in the internet, that SquidGuard can work with. These black lists includes, list of url and domain, usually categorized into content group such as advertising, chat, social network, proxy, porn, webmail, education and many more.
We see content filtering requirements in educational institutions, corporate network etc.
SquidGuard is open source, works with your Squid Proxy server. I have done my implementation on Redhat EL 5.x with squid 2.6
Setting up Web Proxy Autodiscovery Protocol (WPAD) using DNS
In order to use the DNS only method to setup Web Proxy Autodiscovery Protocol (WPAD) you need to check on the following
- To use WPAD using DNS method a DNS entry is needed for a host named WPAD. This name should be resolvable from the clients machine
- Web server must be configured to serve the WPAD file with a MIME type of “application/x-ns-proxy-autoconfig”
- A file named wpad.dat must be located in the WPAD Web server’s root directory.
- The host at the WPAD address must be able to serve a Web page.
- So if you are a member of example.com domain the browser is looking for this url for the PAC file http://wpad.example.com/wpad.dat
Setting up Automatic Proxy Configuration (PAC) file
I tried to make this tutorial for users with medium to advance linux administrative skills. Even if you are not one of those one of them feel free to leave a comment and I shall try to help you out.
To make your Proxy Auto Configuration APC work you need a PAC file and a server to host it.
We shall do it in the following steps
- Write a PAC file with appropriate proxy configuration
- Hosting the file: Put it on a web server where the client browser can access it
- Setting up client browser for suing the PAC file to get and use proxy configuration
- Check if the traffic is going through the proxy server
Proxy auto configuration for an enterprise network
Proxy servers are commonly used in corporate network. I prefer using squid proxy, probably one of the most robust, feature rich proxy servers out there.
I usually use web proxy servers (squid) for end users are used for the following reason
- Cashing of the web contents and DNS, which helps with Internet bandwidth optimization and Faster website load time
- Access control to internet resources, client bandwidth control
- Assist with content filtering (like SquidGuard)
- Maintaining client access log for security compliance
- Protecting client machines from direct exposure to Internet
Setting up proxy server setting in all client machine can be a time consuming business, if we have to manually configure and maintain each and every browser running on the network. However running a transparent proxy on the gateway is a quick and easy to way ensure all traffic goes through proxy server.
Alfresco Document management system is open source
Alfresco is a Document management system, also known as enterprise content management system. While products like google docs and live office making a lot of noise in the document editing market and products like dropbox helping us save and share our documents and other type of files. There is an open market for enterprise class content management system.
Though it is called an ECM, individual users or a small team like can greatly benefit from it.
How would you like to have all your documents searchable on the cloud, group them, categorise them, render them on the fly, download and view them on any device and share them with any group of people. This is what a document management system is all about. Though the product is not targeting individual users or small groups, never the less the benefits are undeniable once you know what you’re missing. Products like google doc and live office are not any document management system, they are just storage for your document with online editors and allow you to share and collaborate them in a very limited way.
Watch this video to see some highlights of alfresco features
On the other hand smart products like Dropbox makes sure your file is always with you. Features like Dropbox offline syncing can be a great extension to alfresco. However seamless integration of Dropbox with various platforms did not come cheap.
Talking about offline file sync, Alfresco do supports CIFS export of its contents; with Microsoft offline sync you can access them offline too.
Alfresco is Open Source Open Standard product, built on java and runs on java tomcat application server and even on Jboss platform.
You can deploy it on your own cloud and set it up without spending a penny for license, which is almost as good as the enterprise edition, and good enough for most of small and medium enterprises.
Feature wise Alfresco lines up with products like Microsoft SharePoint portal and it’s a great alternative to it.
Tag: alfresco, google docs alternative, sharepoint alternative, what is alfresco, Alfresco feature lists, open source
read more on alfresco vs googledocs
Ouya! The next XBOX
As I write this blog I see them in kickstarter, 29 days to go and already got over 500k USD over of their target. That is fast!
Build to have Android running on it makes the possibilities limitless. Games, apps, streaming or just watch tv… and open hack able platform shall probably give birth to some other GPL linux based platform for the end users. While projects like raspberry pi gives you a board for 25$, Ouya plans to give you a fully functional slick box to play with.
Specifications of Ouya
- Tegra3 quad-core processor
- 1GB RAM
- 8GB of internal flash storage
- HDMI connection to the TV, with support for up to 1080p HD
- WiFi 802.11 b/g/n
- Bluetooth LE 4.0
- USB 2.0 (one)
- Wireless controller with standard controls (two analog sticks, d-pad, eight action buttons, a system button), a touchpad
- Android 4.0
This new console will be so open, that its backers are expecting and asking for it to be hacked.
“We decided, ‘let’s take this as far as it can go,” Uhrman said. “So if you want to go in and hack the box, go ahead and do it. We hope you do it.”
In a follow-up e-mail, she was more specific about just how far under the hood the Ouya crew would let a hacker go: “The circuit board will have well-documented test points. People can swap out chips, add, etc. We may even publish the hardware design if enough people are curious. Because Ouya will also have Bluetooth and a USB, hardware hobbyists can also make their own peripherals (someone already suggested pinball controls to us). Regarding the software, you’ll be able to root the device easily. It won’t void your warranty. Every unit has a debug console. We are even working on the idea of a “plant”—which will restore your profile after rooting your device (reverse your root). Because it’s built on Android, you’ll understand the source code well, too. (Obviously if a hacker roots the device, our integrated user experience and game store will no longer be available while the device is rooted — so there is, as always, a tradeoff between customizing your device and enjoying the benefits of standardization. We expect the true hackers to be an elite, but small proportion of the total number of people who buy the box. Most people will probably just use the standard setup.)”
I think this is as close as we go to open source hardware from a commercial hardware vendor. Opening up a new hardware platform in this way bring an enormous opportunity for open source software development in home multimedia platform. This could be the next big thing after IBM PC or android for home multimedia, gaming, automation and many more.
Tag: Ouya, ouya controller, open source software, open source hardware, open source, xbox
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