Entries Tagged as 'Linux'

GNU/Linux Advanced Administration

From Free Tecnology Academy
GNU/Linux Advanced Administration
The GNU/Linux systems have reached an important level of maturity, allowing to integrate them in almost any kind of work environment, from a desktop PC to the sever facilities of a big company.
In the module called “The GNU/Linux operating system”, the main contents are related with system administration. This book is the main documentation for the module.

We will learn how to install and configure several computer services, and how to optimise and synchronise the resources.

The activities that will take place in this module cover the studied topics in a practical approach, applying these concepts in real GNU/Linux systems.

Authors: Remo Suppi Boldrito, Josep Jorba Esteve
Coordinator: Josep Jorba Esteve
Licenses: GNU Free Documentation License, Creative Commons Attribute ShareAlike License
Information: 545 Pages; 18.8 Mb

Free virtual appliance

http://www.turnkeylinux.org/

Turnkey Linux is an open source project developing a free virtual appliance library that features the very best server-oriented open source software. Each virtual appliance is optimized for ease of use and can be deployed in just a few minutes on bare metal, a virtual machine and in the cloud.

Trust Linux! OpenSuse

A team of researchers has implemented support for ‘trusted computing’ in a commercially available version of the open source operating system Linux, breaking new ground in the global drive toward more secure computing environments.

The latest release of openSUSE, a Linux version sponsored by software maker Novell, comes packaged with software that allows users to set up a trusted computing (TC) environment on their computer, enhancing security beyond the antivirus programs and firewalls that frequently prove inadequate at keeping bugs, viruses and spyware at bay.

Promoted and developed by major chipmakers and software companies in the international Trusted Computing Group, trusted computing uses both hardware and software to create a trusted and secure environment, whether on a home PC, a web server, in a data centre or over a corporate network. At the core of the technology is the trusted platform module (TPM), which is a chip that, among other security-boosting features, generates and manages cryptographic keys, verifies the identity of the computer on a network and protects software and data from malicious changes.
Awakening the dormant chip

Many new laptops and increasing numbers of desktop PCs and servers already have TPM chips as standard, while chipmakers such as Intel and AMD have started incorporating the technology directly into their latest generation of processors. However, most TPM chips are currently lying dormant, awaiting activation with the arrival of software that can make use of their enhanced security features.

“The hardware is there… what is needed are operating systems and software to exploit it,” says Herbert Petautschnig, a researcher at Austrian technology group Technikon.

Technikon led a consortium of 23 research and business partners, including AMD, IBM, HP, Infineon and Novell, in developing open source software and applications for TC environments as part of the EU-funded OpenTC project. The group’s implementation of TC support in openSUSE version 11.2 involved building a trusted software stack (TSS) for Linux, developing universal virtualisation layers (including improvements to the Xen hypervisor virtual machine monitor) and creating TC and TPM management software. It constitutes a pioneering implementation of TC technology.

“openSUSE is now the first operating system to offer full TC support,” Petautschnig notes. “Until now, TC had been implemented for specific applications, such as Microsoft’s BitLocker hard drive encryption in Windows Vista and Windows 7 or the fingerprint reader on some HP laptops… With the OpenTC platform we are extending the TC environment to the full operating system and beyond,” the project manager adds.

Unlike traditional security technology that operates only at the software level and only starts protecting a computer after it is loaded, TC technology provides security from the moment the power button is pressed. As the system boots and runs, the OpenTC platform continually monitors the computer for changes and ensures that only trusted, verified software is functioning. In a networked environment, it verifies the identity and integrity of the computer. And it allows different pieces of software and data to be “compartmentalised” so there is no exchange between them even as they share the same computing and/or network resources.
Safer online transactions, trusted corporate networking

OpenTC developed several proof-of-concept applications for the technology. In one, called private electronic transaction (PET), the team showed how it can verify and secure online transactions, such as accessing a bank account. In another, they showed how TC compartments can provide secure remote access to corporate networks, both keeping company information safe on an employee’s home PC and ensuring that the employee’s personal information, photos and games are not visible to their employer.

The ability of TC technology to keep data and processes safely isolated from each other can be extended to enable virtual data centres. As demonstrated by IBM in the OpenTC project, TC software could be used by data centre operators to provide virtualised resources to different clients while sharing the underlying physical infrastructure, thereby ensuring different companies’ data remain separate and secure.

The logical next step, which members of the OpenTC consortium plan to explore in a new project, is to extend TC to cloud computing to enhance the security of services and computational resources provided over the internet. Another project, TECOM, a follow-up initiative to OpenTC that has also received EU funding, will aim to develop TC solutions for embedded platforms, focusing particularly on smart phones and mobile computing applications.

Several of the project partners are commercially exploiting the results of the OpenTC project internally. Petautschnig says they are also open to investor interest to support further development of TC technology. Consortium members are also active in standardisation efforts, helping to extend trusted computing to mobile platforms and the Java programming language, for example.
Despite controversy, a bright future

In the past, TC technology has stirred controversy, not least over its potential for abuse by software and hardware makers to restrict what computer users can do and its applications for digital rights management. However, Petautschnig believes the future for trusted computing systems is bright as the technology starts to be seen as an essential tool in the fight against an intensifying onslaught of hack attacks, viruses and spyware bombarding the world’s computer users.

“Most people will not know that TC components are running on their computers keeping them safe. Conversely, at present most do not know what information is being leaked and stolen by spyware and viruses running on their machines,” Petautschnig notes.

OpenTC project
OpenTC fact sheet on CORDIS

From: Cordis – ICT Results

Resize or Rotate images using nautilus image converter – Ubuntu

You need to install nautilus image converter:

sudo aptitude install nautilus-image-converter

You’ll need to restart nautilus. One option is logout and back in.
You’ll be able to right-click on any image on your machine and you’ll see two new menu items:

resize images
rotate images

Clearing or Resetting the Gnome-Keyring

Command Line Version

rm ~/.gnome2/keyrings/default.
keyring (or login.keyring)

GUI Version

Navigate to Places > Home.  Press ctrl-h for "hidden files".  Navigate to .gnome2 > keyrings.  Delete default.
keyring
file
(or login.keyring).

How You Can Protect Linux and Get YourName@Linux.com

From Amanda at Linux Foundation
Since we launched the Linux Foundation, I’ve been amazed at the passion and willingness to help of Linux users worldwide. This out-pouring of support especially is evident when Linux seems threatened — by a lawsuit, attack by a company, or a combination of the two.  It’s clear that Linux users do not take Linux for granted. In the last six months, we have thought long and hard how to best harness this passion and provide an outlet for this support.

While we  have had an individual membership program since the launch of the Linux Foundation, it’s been somewhat limited in both its impact and the benefits it gives to users. Starting tomorrow that will change. We will announce an expanded individual membership program that will help us promote and protect Linux while delivering tangible advantages to those who wish to support the Linux community’s cause. Most notably, members will receive their own linux.com email address that will showcase to the world — and potential employers — their support for Linux.

Your support goes a long way in enhancing, promoting and protecting Linux for generations to come. But your membership also will connect you with the information, tools and events needed to advance your career and stay current with the platform. We realize altruism only goes so far, so the membership pays for itself with just the LinuxCon, training or O’Reilly discount below. (Your employer may even pay for your membership given the savings on events and training.)

Linux Foundation Benefits:

  • Your own Linux.com email address with forwarding service. Since this is a new service, new users will have a chance to grab a nice alias. (Well, amanda at linux dot com is taken already.)
  • A weekly Linux.com “Briefing Book” with news, technical tips, and analysis to keep you ahead of the curve.
  • 30% off of Linux Foundation LinuxCon 2009 standard registration fees.
  • 20% Discount on registration fees for Linux Foundation Training. This can save you (or your company) a lot of money.
  • A Free Linux Foundation T-shirt so we can showcase your OS of choice at your next company meeting (or at the grocery store, the beach, Presidential news conferences, the Super Bowl, etc.)

Partner Discounts:

  • 35% of O’Reilly Books and E-Books
  • 20% Off O’Reilly’s Open Source Convention (OSCON)
  • 35% of No Starch Press Publications
  • 15% off Subscription to Linux Journal
  • 15% off Neuros Technologies NeurosLink. The Neuros LINK allows you to watch internettv (Hulu, Youtube) as well as downloads on your TV using Linux.
  • 50% off Southern California Linux Expo (SCALE)
  • $10 off every $40 order on Thinkgeek (excluding shipping and taxes)

We hope this program is useful to you, and that you see supporting the promotional, education and protection programs of the Linux Foundation a worthwhile cause. From the legal defense fund, to Linux.com, to our fellows program (currently employing Linus Torvalds), we think these programs are enhancing and protecting Linux now and for future generations. We hope you agree.

To sign up as a member, please visit http://www.linuxfoundation.org/about/join/individual/join

If you have feedback feel free to email me at amanda at linux dot com.

How to enable php (Apache) to connect with PostGresql

The machine is already running, Apache 2, PHP 5. Type these commands:

sudo apt-get install libapache2-mod-auth-pgsql
sudo apt-get install php5-pgsql
sudo /etc/init.d/apache2 restart

Model-View-Controller (MVC)

Problem: The Model-View-Controller (MVC) is a commonly used and powerful architecture for GUIs. How does it work?

Dean Helman wrote (an extract from Objective Toolkit Pro whitepaper):

The MVC paradigm is a way of breaking an application, or even just a piece of an application’s interface, into three parts: the model, the view, and the controller. MVC was originally developed to map the traditional input, processing, output roles into the GUI realm:

Input –> Processing –> Output
Controller –> Model –> View

The user input, the modeling of the external world, and the visual feedback to the user are separated and handled by model, viewport and controller objects. The controller interprets mouse and keyboard inputs from the user and maps these user actions into commands that are sent to the model and/or viewport to effect the appropriate change. The model manages one or more data elements, responds to queries about its state, and responds to instructions to change state. The viewport manages a rectangular area of the display and is responsible for presenting data to the user through a combination of graphics and text.

[...]

[The model is used] to manage information and notify observers when that information changes. [...] It contains only data and functionality that are related by a common purpose [...]. If you need to model two groups of unrelated data and functionality, you create two separate models.

[...] a model encapsulates more than just data and functions that operate on it. A model is meant to serve as a computational approximation or abstraction of some real world process or system. It captures not only the state of a process or system, but how the system works. This makes it very easy to use real-world modeling techniques in defining your models. For example, you could define a model that bridges your computational back-end with your GUI front-end. In this scenario, the model wraps and abstracts the functionality of a computation engine or hardware system and acts as a liaison requesting the real services of the system it models.

[...]

The [view or viewport] is responsible for mapping graphics onto a device. A viewport typically has a one to one correspondence with a display surface and knows how to render to it. A viewport attaches to a model and renders its contents to the display surface. In addition, when the model changes, the viewport automatically redraws the affected part of the image to reflect those changes. [...] there can be multiple viewports onto the same model and each of these viewports can render the contents of the model to a different display surface.

[...]

[A viewport] may be a composite viewport containing several sub-views, which may themselves contain several sub-views.

[...]

A controller is the means by which the user interacts with the application. A controller accepts input from the user and instructs the model and viewport to perform actions based on that input. In effect, the controller is responsible for mapping end-user action to application response. For example, if the user clicks the mouse button or chooses a menu item, the controller is responsible for determining how the application should respond.

[...]

The model, viewport and controller are intimately related and in constant contact. Therefore, they must reference each other. The picture below illustrates the basic Model-View-Controller relationship:

Model View Controller

Model View Controller

The figure above shows the basic lines of communication among the model, viewport and controller. In this figure, the model points to the viewport, which allows it to send the viewport weakly-typed notifications of change. Of course, the model’s viewport pointer is only a base class pointer; the model should know nothing about the kind of viewports which observe it. By contrast, the viewport knows exactly what kind of model it observes. The viewport also has a strongly-typed pointer to the model, allowing it to call any of the model’s functions. In addition, the viewport also has a pointer to the controller, but it should not call functions in the controller aside from those defined in the base class. The reason is you may want to swap out one controller for another, so you’ll need to keep the dependencies minimal. The controller has pointers to both the model and the viewport and knows the type of both. Since the controller defines the behavior of the triad, it must know the type of both the model and the viewport in order to translate user input into application response.

More info:

Ralph Johnson, Model-View-Controller as an Aggregate Design Pattern

Steve Burbeck, How to use Model-View-Controller

Object Arts, Model View Controller

ootips.org