Tag Archives: software development

An Nginx Configuration For Jenkins

Lots of people have posted configurations of Nginx to allow effective proxying of Jenkins when they are both on the same server, but for some reason, it seems that having them on different servers doesn’t seem as commonly discussed. I am using Nginx in my SOHO network to front a few virtual servers, and provide them all via the few IPs I have on my Comcast Business Class connection. That means having a proxy that can serve up the various systems supporting various domains.

We’ve covered how to build a Jenkins server, so for the sake of documenting this additional capability, here’s my configuration:

server {
  listen 80;
  server_name jenkins.domain.com;

  access_log /var/log/nginx/jenkins_access.log main buffer=32k;
  error_log /var/log/nginx/jenkins_error.log;

  rewrite /jenkins/(.*) /$1 last;

  location / {
    proxy_pass       http://192.168.1.115:8080/jenkins/;
    proxy_redirect   off;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    # max upload size
    client_max_body_size       20m;
    client_body_buffer_size    128k;
    proxy_connect_timeout      90;
    proxy_send_timeout         90;
    proxy_read_timeout         90;
    proxy_buffer_size          4k;
    proxy_buffers              4 32k;
    proxy_busy_buffers_size    64k;
    proxy_temp_file_write_size 64k;
  }

}
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Continuous Integration With Jenkins On Ubuntu 11.10

First, install Ubuntu Server 11.10. Obviously, settings will vary from machine to machine, but when you get to the page for selecting software to be installed, make sure you select both the OpenSSH server and the Tomcat server.

Ubuntu Software Selections

With a fresh server install, you’ll want to assign a static IP to your server. Ubuntu Server 11.10 will likely detect your network card, and set it up during install to use DHCP. But, it makes more sense for a server to have a stable IP. You can change this in /etc/network/interfaces. Change the section that likely reads as:

iface eth0 inet dhcp

to something like:

iface eth0 inet static
  address 192.168.x.x
  netmask 255.255.255.0
  gateway 192.168.x.1

Of course, use whatever local LAN network addresses make sense for you. Either restart the network service (sudo /etc/init.d/networking start) or reboot.

When you’ve rebooted, make sure to update Ubuntu itself.

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo reboot

Jenkins is a Java app that needs some environment to run it. We’ve already installed Tomcat for this through the Ubuntu installer. You can verify it is running by surfing to: http://%5Byour IP address]:8080. You may also want to configure http://%5Byour IP address]:8080/manager/html. Surfing over to that page will give you the info needed to configure the status page viewer when you fail login on the attempt on the new Tomcat server. The other reason is that this management page allows you to easily deploy the Jenkins WAR too. Download the WAR for the Ubuntu distribution and upload it via the Tomcat manager app.

If you now surf over to http://%5Byour IP address]:8080/jenkins, you will see Jenkins, but in an error state. It will complain that it is “Unable to create the home directory ‘/usr/share/tomcat6/.jenkins’. This is most likely a permission problem.”. Well, at least Jenkins is running! The easy way to solve this is to let Tomcat have access to that folder.

$ cd /usr/share/tomcat6
$ sudo mkdir .jenkins
$ sudo chown tomcat6:nogroup .jenkins
$ sudo /etc/init.d/tomcat6 restart

That should get you going on your adventure in continuous integration with Jenkins.

Architecting A C# Web-Based Application: Introduction

I am beginning a series of articles on architecting a “serious business” web-focused application. The raison d’ĂȘtre for this is because I have been unable to find a focused, well-documented sample project that exposes practical architecture and guidelines. The overall goal is to put myself on the line as a guinea pig, journal my thought process at every step, take the abuse and, hopefully, generate some positive discussion on the choices I make along the way. The secondary goal is to provide intermediate developers an example of how to approach a common type of project. As such, the series will not be an exploration of cutting-edge technologies, or of advanced coding techniques.

The sample application will be a project management application that follows the great majority of the basic Scrum principles, allows a development team to better manage their workload, and also maximizes the offload of data entry and organizing to the stakeholders as much as possible. I know that this type of application exists in umpteen forms on the net. Let’s face it, it’s basically the “enterprisey” equivalent of Tetris. However, I selected it for three main reasons:

  • The project is a neither too complex, nor uselessly simple in scope
  • It is a domain that should not be foreign to a readership composed of developers
  • I need a good app that fits the way my team works, rather than the overly generic and bloated PM software out there. While this may seem selfish, it’s actually good! I’ll be eating my own dogfood.

I think many developers don’t enjoy the use of most of the PM software out there because they become responsible for too much maintenance/clerical work. Not many packages out there put as much responsibility for the project in the hands of the stakeholders, and if they do, invariably they charge for more licenses. We’ll start simple, focus on providing a great UI, and won’t involve feature-creep just to gain bullet points on a sales presentation. Ultimately, the code base will be provided at large as an open-source project.

The whole solution will consist of your typical moving parts:

  • A web-based client where the majority of the interaction with the system is done, especially the collaborative parts.
  • A task bar application that allows quick data entry, primarily by developers, for common functions.
  • A middle layer built to handle the above two clients, and open for more. This will be where all the rules, workflows, transformations and other tasks happen. This will also force one to consider how to build the layers.
  • The database layer, obviously used to persist data.

The minimal functionality we will provide for a “v1.0” is:

  • The ability to work with the four general “things” found in Scrum: roles, timeboxes, artifacts and rules.
  • Allow business users to easily log ideas (a.k.a. user stories) and track the status thereof.
  • A robust and customizable workflow system for managing rules that, while not very dynamic, should be open to some amount of customization.
  • Some dashboarding for some simple metrics.
  • While we won’t aim to provide a full interactivity suite, it would be nice to build in a way to have a threaded discussion area for each idea or story, such that devs and users can collaborate and flesh out ideas in a way that doesn’t create an email nightmare.
  • A cross-platform, browser-based user interface with a form-based authentication system.
  • Optionally integrate logins with AD or other LDAP system.
  • A small taskbar application that helps you track what you are currently working on and gives feedback on changes in the app.

As you can see, this is not a simple throw-away project. But, neither is it a highly-complex, enterprise application. I hope that this series can help junior and intermediate .NET developers get a feel for how to approach the design of a web application, elevate my own game through feedback both high and low, and for intermediate to senior developers to collaborate on different approaches effectively by having the constraint of a defined scope in play. (Lots of times, comments on blogs like this run the gamut because some people are thinking of more complex projects than others.)

The next articles will cover the typical questions you (should?) have when you kick of a project:

  • What exactly am I talking about? Let’s spend some time on some diagramming and scoping to understand the larger moving parts. We’ll obviously iterate and refactor to get it right along the way, and so let’s not paralyze ourselves early, but we do need to establish some common language between the participants.
  • What tools am I going to use? For example, what framework will we use to get data in and out of our application? And, why? Another example is the many forms of IoC containers out there. Which one and why?
  • How am I going to structure all this practically? Let’s talk about overarching principles/methodologies that we will choose to apply on this project. Let’s also establish the subprojects in the overall solution from a technical standpoint.

Please, if you have any suggestions or comments, serve them up now! Especially if there’s anything in particular, top-level, that you think should be included. And, I hope you join me actively in subsequent posts.

Top 13 Funny Software Development Quotes

Over the years, I’ve collected some of the smartest-yet-funny software development quotes I have read. Here’s the current short list in no particular order. Oddly enough, there are thirteen of them and they all address the woes of programming.

Feel free to add any like quotes in the comment section!

  1. “The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time.” – Tom Cargill
  2. “In order to understand recursion, one must first understand recursion.” – Author Unknown
  3. “I have always wished for my computer to be as easy to use as my telephone; my wish has come true because I can no longer figure out how to use my telephone.” – Bjarne Stroustrup
  4. “A computer lets you make more mistakes faster than any other invention in human history, with the possible exceptions of handguns and tequila.” – Mitch Ratcliffe
  5. “There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.” -C.A.R. Hoare
  6. “The gap between theory and practice is not as wide in theory as it is in practice.” – Author Unknown
  7. “If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization.” – Gerald Weinberg
  8. “If debugging is the process of removing software bugs, then programming must be the process of putting them in.” – Edsger Dijkstra
  9. “Measuring programming progress by lines of code is like measuring aircraft building progress by weight.” – Bill Gates
  10. “Nine people can’t make a baby in a month.” – Fred Brooks
  11. “Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.” – Rich Cook
  12. “There are two major products that come out of Berkeley: LSD and UNIX. We don’t believe this to be a coincidence.” – Jeremy S. Anderson
  13. “Before software can be reusable it first has to be usable.” – Ralph Johnson