Enterprise Linux Log


January 16, 2008  12:46 PM

Trac(king) software development

Kutz Profile: Akutz

If you are a software developer, you need Trac and you need it now. There is no other open-source, software management tool more useful to a software project life-cycle than Trac. Straight from the Trac website , Trac is an “enhanced wiki and issue tracking system for software development projects.” But it is so much more than that.

Subversion

Trac integrates with Subversion repositories to provide a browser view of your code. This is a great feature for when you want to peruse some code in a project without wanting to bring up your IDE. The browser will show diffs, a history and even allow you to compare different revisions so you can see how the code has evolved. To see what I am talking about you can look at Trac’s own browser view.

Timelines, roadmaps, tickets

Trac allows you to see where you’ve been, where you want to go, and allows you to track issues along the way. The timeline feature allows developers to track the history of the project and understand its current status. The roadmap enables administrators to create project milestones. Finally, the powerful tracking system lets developers, administrators and even users create and modify bug reports, or feature requests, as they pertain to the project.

Permissions

You may have noticed that I began making a distinction between developers, administrators and users. Trac has a very detailed permissions support that enables a Trac administrator to assign rights to specific users and developers at granular levels. Let’s say that you don’t want guest users browsing your code — just take away that permission. Or perhaps you only want registered developers to be able to create new tickets? This is easily accomplished.

Beauty

Looking at the Trac browser, you cannot deny how absolutely gorgeous the Trac interface is. Not since Audrey Hepburn has anyone or anything epitomized simple elegance the way the Trac project does (maybe Katherine Heigel comes close?) And the interface is fully customizable. My own Trac installation looks nothing like the default install. You can make simple changes such as adding a custom banner image or completely redesigning the entire look and feel of the site through the wonderful Genshi templating system.

Community

One of the most appealing aspects of the Trac project is the fact that it is not managed or developed behind closed doors. In fact, the development community is incredibly open and welcoming to ideas. Most of the time, any of the lead developers (osimons, aat, coderanger) can be found on the Trac IRC channel (freenet#trac), and they are more than happy to help you.

Stay on Trac

Trac is a superb example of what can be accomplished when developers see a need and fill it. That being said, the excellent product that is Edgewall should not be overlooked either. Trac provides almost every possible feature you could want in a software development management system, and it does so with sheer elegance.

January 16, 2008  11:08 AM

The ‘perfect’ CentOS 4.6 server

Keith Harrell Profile: SAS70ExPERT

The gang at howtoforge.com has posted another good guide. This one is a step-by-step for setting up a CentOS 4.6 based server for ISPs and Web hosters. LAMP, email, DNS, FTP and ISPConfig are all included.

If you use it, tell us about your experience. Or, if you have a Linux tutorial that you think might be helpful and would like to share it with our users, send us an email.


January 14, 2008  10:27 AM

Server platform consistency for Linux systems

Rick Vanover Rick Vanover Profile: Rick Vanover

Today’s top server hardware vendors have expanded the line of Linux compatible server systems. HP and Dell, for example, have Red Hat Enterprise Linux (RHEL) and Novell SUSE Enterprise Linux available as OEM build installations, the same hardware that a Windows server can be built on. As recommended configurations from the vendors are quite similar, this can make any server purchases a little easier to swallow. Because configurations are similar for Windows and Enterprise Linux builds, these servers can be repurposed to change their roles to Windows or Linux without additional equipment.

Take for example the HP ProLiant DL 380 G5 and the Dell PowerEdge 2950 III, which can be configured for a general purpose Windows or Linux server and can have most connectivity options available: fiber networking interfaces, storage area network (SAN) fiber channel adapters and any additional copper networking. The local drive configurations currently use serial attached SCSI (SAS) drives with local array controller. 

Dell and HP generally divide models by Intel and AMD processor offerings, so the selection process is aided by that distinction. If you strive for a common server for the Enterprise Linux builds and the Windows server space, a uniform processor brand platform is a must. 

Choose wisely

If you embark on the single server across software groups, be sure to get all members on board and mutually agree on a server specification. If the needs are different, it may be more likely to work in terms of base server and customize up as required. This can save the incremental cost of a small number of under-utilized servers in a mixed environment. 


January 11, 2008  11:05 AM

Making the case for JeOS

Rick Vanover Rick Vanover Profile: Rick Vanover

I recently tried out a test system with an Ubuntu Server 7.10 JeOS build. The JeOS (Just Enough Operating System, pronounced “juice” ) concept for Linux works well if one needs just enough to run a test system. JeOS builds are popular for software vendors that are making purpose built systems, small footprint test systems, or a virtual appliance environment for popular virtualization technologies.

What composes a JeOS distro?

Simply put, not much. JeOS distributions are a skinny, bare-bones build made to occupy a small footprint and provide only explicit system services on the install. The JeOS distributions follow their full build counterparts in the same versioning and install interface, just with less options for install from the CD media.

Start with nothing, add only what is needed

JeOS distributions are perfect for this practice for many reasons. My particular need was an external facing DNS server, so the skinny JeOS did a great job and installed the DNS server, a boot loader and the OS essentials. This also made for a smaller drive footprint – only 500 MB (as a virtual system). The JeOS install CDs are smaller than the full version counterparts, but have a similar look and feel for the install process.

Playing nicely

Should you need to add a package that was not on the CD, you can use the standard retrieval tools. For my Ubuntu 7.10 JeOS system, this included sudo apt-get. This option is handy should I need to add a web server engine or database. Also, you can make the JeOS builds fit your existing enterprise Linux environments by adding the tools and packages you expect to be installed, but starting with less on the base install. 

JeOS distributions do not run a different Linux kernel than the full version equivalent, they simply have less packages. Ubuntu 7.10 Gutsy Gibbon and the JeOS equivalent are both at kernel 2.6.22. Plus, Canonical Ltd. provides support options for the Ubuntu JeOS – which is nice.


January 9, 2008  1:32 PM

Use virtual keyboards to support international Linux systems

Rick Vanover Rick Vanover Profile: Rick Vanover

Should you be so privileged as to be in a position to have to support international enterprise Linux installs or distributions, you may run into the occasional situation where you need local characters and your keyboard can’t offer much help. I had a chance to run a tool called Javascript VirtualKeyboard (JVKb) that you can host locally to give you access to the international keyboard and the characters contained. This tool will offer a floating keyboard localized in your choice of many languages. I’ll show you how I used it and how it may help any of your situations where you need local characters or on a remote system need an English (US) keyboard.

Getting Started is Straightforward

JVKb is obtained as a single tar file that you extract, and then access via an HTML page. There is no install required for JVKb, but a Java runtime environment (jre) is required to execute the Javascript (.js) files. Most current Linux builds will provide a compatible jre for JVKb. You could also extract the files and host them centrally to keep an even smaller footprint for your systems where you may need another language in the form of a keyboard.

Running JVKb on Demand

Because there is no install, we can launch the JVKb as needed. I opened up the HTML file and launched a pop-up keyboard, here is a Czech keyboard popping up on my CentOS Linux console in GNOME:

Czech language floating keyboard

I also am able to access the JVKb within a VNC session, which would be helpful if the system is remote. Here is a Greek keyboard floating within a VNC session:

Greek Keyboard within VNC

Limitations

JVKb is not robust, but since it is free we should not complain too much. It would save time if it mapped over the sessions keyboard instead of relying on copy and paste. Also, all characters that appear may not be available in the virtual keyboards. The other limitation is that it cannot be launched or used within a terminal or SSH session. 

This application is helpful in several different ways, but the missing character problem may also be a nuisance if you come across a password that is set to contain a character from the other language. Watch your remote installations for this.


January 7, 2008  2:29 PM

Set up a Samba Domain Controller with LDAP for Ubuntu server

Rick Vanover Keith Harrell Profile: SAS70ExPERT

Hey Ubuntu fans – ever wanted a domain controller with an LDAP back end for a server but couldn’t bring yourself to run Windows? Well, the guys over at HowtoForge assembled a great how-to guide for setting up a Samba Domain Controller with an OpenLDAP directory that authenticates like a Windows Server 2003 Domain Controller. The Samba LDAP configuration doesn’t make for a fully comparable Windows domain controller, but it does give your Ubuntu server LDAP authentication (so you have that going for you, which is nice). And the author also points out that this setup can be expanded to spread out authentication over multiple networks to include slave servers and Microsoft XP boxes.

If that interests you, check out the sample chapter on OpenLDAP and the guide to Samba and Active Directory on SearchEnterpriseLinux.com.

(Does the Caddyshack reference make up for the shameless plug?)


January 3, 2008  1:10 PM

Red Hat Enterprise Linux in lockstep: CentOS 4 receives an upgrade

Rick Vanover Rick Vanover Profile: Rick Vanover

CentOS continues to assert itself as a strong but free equivalent to Red Hat Enterprise Linux (RHEL) with the release of CentOS 4.6 on December 16, 2007.  CentOS distributions are spaced approximately 1 month later than the RHEL equivalent (RHEL 4.6 was released on November 15, 2007.) While this update of the 4.x series is new, both RHEL and CentOS concurrently release updates to the 5.x series as well. CentOS 5.1 and RHEL 5.1 were released in early December, indicating concurrent development for the 4.x and 5.x products simultaneously. The4.x and 5.x releases are different in that the 4.6 releases do not update all the modules as far in advance as their 5.1 counterparts.

Under the Hood

CentOS 4.6 is modeling RHEL 4.6 in all major categories, such as kernel, bind, gcc, mysql and perl. A few differences in package version details can be found, with CentOS 4.6 being slightly newer (e.g. evolution package). The upgrade is available as a new install from downloadable .ISO images or a yum-based upgrade described in the release notes. RHEL 4.6’s release notes are located here for i386 and x64 platforms.

RHEL Version Matching

With CentOS keeping compatability in parallel with RHEL, enterprises are provided a free development environment for new concept systems for enterprise Linux distributions. The two platforms offer a benefit of having one for testing and quality assurance purposes that can be provided in situations where an operating system environment may be the potential for the issue. The Microsoft world cannot offer this, but it is quite common in mission critical systems where a totally different platform (and possibly the program and code) are ported to fully meet operational requirements with nothing in common among member systems.

CentOS continues to assert itself as a strong selection for its RHEL compatability, minus the commercial support.


January 3, 2008  12:58 PM

Run instant messaging internally, securely

Rick Vanover Rick Vanover Profile: Rick Vanover

Have you found Instant Messaging (IM) running on just about every box in your enterprise? Want to secure IM? Meet Jabber. Jabber is a streaming XML based open source instant messenger server.  You can provision a Linux server to host the Jabber server quite easily and more securely on your own network.

Building a Jabber Server

A jabber server builds from the jabberd2.x release, which is licensed under the GPL. Once running, a jabber server will provide support for your internal IM clients. Should you need to have external IM contacts that cannot connect to your internal IM server, some of the jabber clients can connect contacts from other Internet IM services.

The enterprise IM server can also take a big load off of your email server from a storage and message traffic perspective. Too many times, long threads of email traffic with one-line replies waste resources on your expensive email system. A (free) IM service on your network would be a better solution for messaging that is not important to store per long-term email retention policies for storage.

IM in the enterprise

The Jabber client offers more options for Windows, Linux and Mac operating systems, but IM over the Internet for business matters is not a good practice. Security rules can be violated in practice by sending passwords, sensitive files and personnel data because users may find it quicker and easier than correct mechanisms.


January 1, 2008  9:32 PM

Enterprise streaming media? Sure, and on virtual Linux systems!

Rick Vanover Rick Vanover Profile: Rick Vanover

Many IT shops have strict policies prohibiting the storage of multimedia content on shared systems. Issues over copyrighted content and inappropriate material pose many problems. However, more business products offer various content in audio or video media. These can be training videos, quality assurance audio recordings, company commercials for employee viewing, bandwidth abuse or even music for lobby purposes.  Several options for a streaming multimedia server are available in Enterprise Linux environments.

Streaming multimedia storage

Some of these options include icecast, gnump3d, jinzora and shoutcast. I had an opportunity to configure GNUMP3d on my CentOS linux system and found it quite a good solution. For GNUP3d, the install was obtaining a tar file and a simple extraction, then running the following command:

make install

The GNUMP3d server configuration file is located at /gnump3d-3.0/etc/gnump3d.conf in the path where you extracted your tar file. Reading through this file is fairly intuitive and you can point your media path, some basic performance options, host server configuration, and security settings. Once it is saved and index operation is performed and the service started as /gnump3d-3.0/bin/gnump3d2 to start the service. From there, a website is up and running with your indexed media.

Some further customization of the interface to brand it to your Intranet would be a good idea as it is fairly basic and looks like free software. The various packages offer different levels of functionality and levels of the look and feel. GNUMP3d gets a star because it can be configured and running in a matter of five minutes.

Client streaming strategy

Virtual Linux environments can host these systems, especially if there is any concern about the bandwidth required if rolling this solution into existing Linux systems. Some bandwidth throttling and front-side firewalling may also be a good idea to ensure the intended audiences — even internally — are able to access this content for all configurations. For example, if you have many remote sites on limited bandwidth, the streaming media would not be appropriate.


December 21, 2007  5:55 PM

Changes at Red Hat: A new CEO in 2008

ITKE ITKE Profile: ITKE

CNET news is reporting that Red Hat CEO Matthew Szulik is stepping down effective January 1st and handing control of the world’s most popular enterprise Linux provider to former Delta airlines COO James Whitehurst. The article reassures us that Mr. Whitehurst is a good pick, as he used to be a programmer himself and runs four distributions of Linux at home. But how might this change in leadership affect Red Hat?

History has not smiled kindly on CxO changes, which have ranged from forcible replacements — such as Steve Jobs to Pepsi-exec John Sculley in 1985 — to planned transitions, as when Michael Dell handed the reigns over to Kevin B. Rollins in 2004. Both events resulted in the eventual return of the original CxO due to the replacements’ inability to maintain the success of the company. Is Szulik destined to return to Red Hat in a few years?

Let’s take a look at Whitehurst. According to BusinessWeek, Whitehurst has degrees in Computer Science from Rice and in business from Harvard. However, if we should judge him by his actions and not his credentials, perhaps we should be a bit more worried. Shortly after he was hired by Delta airlines in July of 2005, Delta filed for Chapter-11 bankruptcy in September. Of course, not knowing the specifics of his involvement one could also easily assume that it was Whitehurst who helped lead Delta out of bankruptcy by working on the plan that was finally accepted in August of this year by the Bankruptcy Court.

I wish Whitehurst the best at Red Hat, I truly do. I guess I am hoping what many other Red Hat fans are hoping: Don’t mess it up!

Red Hat understands enterprise business needs, so I hope that Whitehurst does not take the approach that many other incoming CEOs do: restructuring the company to fit their desires, not restructuring themselves to fit the company. I recently wrote an article on where Red Hat needs to go in the next year to trump its rivals. Mr. Whitehurst, feel free to use my business plan.

Meanwhile, the whole Linux world is watching.


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