Written for OPS235 Course – Software and Installation Process

By , 2015-03-29 23:30

lamp-featuredSoftware installed

Apache

Apache is an open-source web server software maintained by the Apache Software Foundation and the open-source community. It can be extended using modules, and is well-documented and well-supported. It is usually the de-facto standard Web server on Linux, although lately new and customized Web servers such as nginx have been becoming more popular for dynamic, high-traffic sites.

PHP

PHP is a server-side scripting language mainly used for web development. By writing PHP rather than plain HTML, developers are able to create pages that are dynamically generated by the server on the fly depending on parameters provided. The Zend PHP interpreter is open-source software, and is available as a module for multiple Web servers on Linux, Windows, BSD and other OSes.

MySQL

MySQL is an open source relational database management system (RDBMS). It is open-source software, released under the GPL and sponsored by Oracle Corporation. The software is available at no cost, although there are also some paid versions. It has widespread use in Web applications, such as WordPress and MediaWiki, and is also used by large sites such as Facebook and YouTube.

LAMP stack

Together, CentOS (Linux), Apache, MySQL and PHP form an implementation of a LAMP stack. This stack provides a consistent, portable environment for Web developers.

WordPress

WordPress is an open-source blogging platform and CMS. It is written in PHP, and uses a MySQL database for text content storage and metadata. It provides an easy-to-use user interface, and is highly extensible and customizable with a large number of user-creatable themes and plugins. WordPress powers some prominent sites such as Forbes.com, vogue.com and nationalpost.com.

Problems encountered during installation

  • The systemctl command was not available, since this install of CentOS is using upstart rather than systemd.
  • There was no default index page created during the install of httpd. As a result, accessing HTTP on the Centos3 VM server gave an HTTP error 403 (Access denied) – the default Apache configuration denies directory listings.
  • The c6host machine was not able to access the HTTP service on centos3 because its iptables was not configured to allow inbound traffic on port 80.
  • When configuring iptables on centos3, running iptables -A INPUT -p tcp –dport 80 -j ACCEPT was notsufficient.
    • The -A option appends the rule to the end of the INPUT chain, however, there was a pre-existing explicit rule rejecting all packets.
       REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited
    • To move the new rule above the reject rule, the incorrect rule had to be removed by running iptables -D INPUT -p tcp –dport 80 -j ACCEPT
    • Then, find the line numbers by running iptables -L –line-numbers
       Chain INPUT (policy ACCEPT)
       num  target     prot opt source               destination
       1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
       2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0
       3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
       4    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22
       5    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited
    • Use iptables -I INPUT 5 -p tcp –dport 80 -j ACCEPT to insert the new rule above the existing rule 5.
    • Running iptables -L –line-numbers again gives the following output:
      Chain INPUT (policy ACCEPT)
      num  target     prot opt source               destination
      1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
      2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0
      3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
      4    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22
      5    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:80
      6    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited
  • The contents of the WordPress .tar.gz file were extracted to /root/wordpress. Moving this directory to /var/www/html resulted in the Apache process not being able to read the wordpress subdirectory. Copying (cp -R) avoids this issue.
  • When configuring the WordPress connection to MySQL, the WordPress documentation said to run the query
    mysql> GRANT ALL PRIVILEGES ON databasename.* TO "wordpressusername"@"hostname"
        -> IDENTIFIED BY "password";

    to allow access to the database. However, since the MySQL server and Apache/WordPress are installed on the same host, we need to use “localhost” rather than “centos3” for the hostname.

Trick PHP into thinking SSL/HTTPS is on

By , 2014-10-15 08:53

Not sure of the implications of this/best practices, but I just added

$_SERVER['HTTPS'] = 'on';

to my index.php.

Reason for this is that I am running a php app behind a reverse proxy, with the connection between the app server and the reverse proxy being plain HTTP, but the connection between the client and the reverse proxy is HTTPS.



Enabling DVD playback on Ubuntu 14.04

By , 2014-08-02 21:37

I don’t really play DVDs on my PCs much anymore, but my brother have me the full boxed set of Freaks and Geeks (great show, cancelled too soon). Running on a fresh install of Ubuntu 14.04, I popped in the DVD and was prompted by “Video Player” aka Totem to install some additional codecs. I obliged, but after the installation, the DVD still wouldn’t play. It turns out that because of legal issues, the libdvdcss2 library is no longer included in the Ubuntu repositories. However, the libdvdread4 package does provide a script to easily install it.

Once you have libdvdread4 installed, run following script:

# sudo /usr/share/doc/libdvdread4/install-css.sh

Restart your video player and enjoy your DVD.

Screenshot from 2014-08-03 01:35:17

uptime

By , 2014-07-31 15:32

I noticed that my workstation has been up essentially since I made my last blog post.
129 days and counting.

 $ uptime
 15:22:40 up 129 days,  2:41,  5 users,  load average: 1.88, 1.91, 1.93

This system also hasn’t been re-installed since November 2012. The initial install was done using the Ubuntu 12.10 “Quantal Quetzal” CD on November 20, 2012. I’ve since upgraded to every interim release – 13.04, 13.10 and now 14.04, and used a host of different desktop environments and window managers (currently using i3). The PC actually hasn’t been rebooted since installing 14.04; I only restarted X.

[email protected]:/var/log/installer$ ls -l
total 1532
-rw------- 1 root   root   1303 Nov 20  2012 casper.log
-rw------- 1 root   root   3856 Nov 20  2012 debug
-rw-r--r-- 1 root   root 420116 Nov 20  2012 initial-status.gz
-rw-r--r-- 1 root   root     59 Nov 20  2012 media-info
-rw------- 1 root   root 747016 Nov 20  2012 partman
-rw------- 1 syslog adm  377562 Nov 20  2012 syslog
-rw------- 1 root   root     17 Nov 20  2012 version
[email protected]:/var/log/installer$ sudo cat media-info 
Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
[email protected]:/var/log/installer$

 

Selection_111

Windows XP

By , 2014-03-22 15:03

Windows XP is going out of support next month.. This means Microsoft will no longer provide security updates or any patches for the OS, leaving users of the 12-year old version of Windows more vulnerable to emerging threats.

On this occasion, let’s take a moment to put dear old WinXP’s age in perspective. But first, some mood music:

When Windows XP was released…

Bill Gates was still CEO of Microsoft.

APW2001110119927

Gates with his new baby. Also Alias.

Friends, Buffy the Vampire Slayer, The X-Files, Frasier and Sex and the City were still airing new episodes.

btvs_s6e8

Vampires were still scary.

Friends Gets 11 Emmy Nominations

The one where Monica and Chandler are married and Rachel is freaking out.

We had yet to see shows like The Office, Arrested Development, House and How I Met Your Mother.

house-md_0001 2

There was no Gregory House in 2001.

The current-gen iMac had a CRT display.

imac_indigo

This was the competition.

There was only The Matrix.

matrix_revisited copy

This was true in 2001.

The “War on Terror” had only just begun.

The President of the USA.

The President of the USA.

The BlackBerry 950 was the current model.

rimblackberry950-1356315472-1

Portable productivity for the business professional.

How to buy technology

By , 2014-01-09 19:28

Being  a “computer” guy, I often get asked all kinds of questions related to technology.

Some questions that come up quite often are “What kind of laptop should I buy?” or “What do you think of [insert name of tablet]?” or “My laptop is old. I need a new one, but I’m thinking of Windows 8/iPad/Android instead. What are your thoughts?”

The best advice I can offer anyone is:

What are you looking for in your electronic device?

Whether you’re shopping for a car, a house, a phone etc. it helps to know what you’re looking for. If you work in construction and need to haul 2x4s and bricks and things fairly often, a sport coupé is probably not the right car for you. Likewise, when picking a mobile computing device, you should think about what you need the device to be able to do. So, before shopping, take a step back and evaluate your needs and wants for your mobile computer.

So, before even looking at the latest Best Buy flyer – a few questions to ponder:

  • What are the workloads? Word processing, web browsing, YouTube (HD), e-mail, gaming, music, photo editing, etc.
  • What kind of apps do you want to use?
  • Where will you be using the device? In class? On the train/bus? In meetings? At your desk?
  • Will you be carrying the device a lot? In a bag?
  • Are you looking for something stylish? flashy? durable?
  • Do you really need a portable device? Desktop computers are still a good option, and there are interesting all-in-one options.

There are all kinds of technology form factors today, and more being created all the time. Everyone’s needs and preferences are different, but there’s probably a device that’s just right.

Keyboard test

By , 2013-09-16 02:17

– Are you mad at your computer?
– I type with purpose.

Is a mechanical keyboard really better to type on?
I’m not sure yet but it certainly is louder. It’s really loud. I washed this keyboard this morning, getting rid of 20 years of dust and grime. Hopefully I didn’t damage the electronics with all the water. It seems OK now, but earlier I was getting some double letters. The model M is a buckling spring keyboard. Some say that’s the best type of mechanical keyboard. Never tried others myself – Cherry MX switches and the like. Those fancy keyboards from Filco and Das Keyboard look great, but I still can’t see myself paying $100 for an input device. I suppose I don’t really spend enough time actually typing for it to be worth it. This particular Model M was salvaged from the trash bin. It’s a cool white colour and not the usual grey/beige. It’s also branded Ambra (a Canadian IBM brand) rather than IBM or Lexmark. Manufacturing date is 1993. I’m also currently using an IBM PS/2 mouse. It’s actually a fantastic quality “ball” mouse, way better than the late cheap OEM mice that came with PCs in the early ’00s before optical mice became the norm. The mouse is light, the cursor responds great… if only this thing had a scroll wheel.

OK, now that I’ve typed a few lines on the mechanical keyboard, let’s try the total opposite.

Here we go, typing on an Apple Aluminium keyboard. Chiclet-style keys, virtually flat – identical to MacBook keyboards. Very different feel when typing, obviously. Hands are also in a different position, this keyboard is very low to the table. I’m actually not sure which one I prefer. I feel like there are a lot more “shocks” going through my hand when my fingers hit the keys on the Apple keyboard, since the key travel isn’t very far. This keyboard is actually surprisingly loud, especially the space bar. Having volume function keys is nice.

Let’s try the IBM again.

Back on the Model M. A lot more noise. How about the typing feel? It feels pretty good. More natural to type on here than on the Apple. I had read online something about not having to press the keys as far since the keys actuate before actually being pushed in all the way. Not sure if that’s how I’d describe the feeling of typing on here. The thing that strikes me most is the really springy feel – which is to be expected, after all, the keys each have a physical spring underneath them. I’m going to have to try a typing test using both keyboards to see how many WPM I get. The model M seems to have issues with Backspace sometimes. Probably due to the PS2 to USB adapter I had to use to connect it to the laptop.

Canada Day fireworks GIFs

By , 2013-07-02 13:22

IMAG1109_BURST010-MOTION IMAG1108_BURST002_COVER-MOTION IMAG1110_BURST003-MOTION

Cost savings: Follow-up

By , 2013-06-14 18:01

It’s been a few months, probably a good time to see how I’m doing with my cost savings goals.

1. Cancel Fibe TV. Haven’t done it. I seriously made an effort though, but I can’t receive OTA HDTV in my apartment. Turns out despite being on the 29th floor, I have no line of sight with the CN tower or any other local broadcast tower. I did however cut down my subscription package to the absolute minimum and got the Fibe Internet “dependency” reduced to $0 monthly.
2. Cancel landline. Well, I didn’t do this one either. It kind of ties in with the first point; I did get the price reduced enough that it costs less than the dry loop I’d need if I did cancel.
3. Be more energy conscious. I’ve been making sure to switch off any electric service when not necessary. I don’t leave my desktop computer on all the time anymore, my home server is a low power, compact system.
4. Move to the cloud. Nothing done on this front yet.
5. Cancel personal smartphone. Done. I no longer carry two smartphones, I’ve settled on an HTC One (great device) as my only phone. Saving more than $50/month.
6. Stop buying random stuff. Well I haven’t really bought random tech, but I did go on a trip to Greece… Expensive, but so worth it!

So, overall, not doing too well. But I think it’s a start.

Cost savings

By , 2013-04-06 11:23

Lately I’ve been reviewing my finances. I haven’t exactly been frugal over the past few years, and now that I’ve moved into a proper (and considerably more expensive) apartment, it’s time to grow up and take responsibility.

So far, I’ve found the following cost-saving opportunities:

  1. Cancel Bell Fibe TV. As cool as I find IPTV, and despite the convenience of having loads of TV channels with a PVR, the fact is I don’t really watch that much TV. I do most of my media consumption via the Internet (like most other kids these days), and probably 80% of my live TV watching consists of CBC (The National, Strombo) and CityTV (BT, Community, Parks and Rec) – both of which are available in ATSC HD over-the-air here in Toronto. Combine that with XBMC‘s new PVR functionality and there’s no real reason to keep a TV service.
  2. Cancel landline phone. Yes, I still have a landline. Landlines are cool. (I think I see a recurring theme here…) When I was little (and unburdened with privacy concerns) I loved the idea of being listed in the white pages. Later on, the PSTN gained a certain mystery, hearkening back to the days of dial-up internet, phreakers with their boxes, live telephone operators, teenagers wanting their own phone lines, all the way back to the early 20th century. But the fact is that now in the early 21st century, the age of the PSTN is past. I’m not even sure I make one voice call a week outside of work. It’s gotten to the point where I once flashed a CyanogenMod nightly onto my phone and used it for a week before realizing the Phone app was broken. All that and the simple fact that landlines are freaking expensive. Bell wants $28.98/month before tax for “Home Phone Lite“. Freephoneline.ca offers a VoIP number for $0/month.
  3. Be more energy-conscious. For the first time, I have my own hydro bill. I went out and bought a Kill-A-Watt and started checking all my electronics’ and appliances’ power consumption. More on this later.
  4. Move to the cloud. The public cloud, that is. I have a 1U server in a datacentre in Missisauga hosting a few VMs, including this blog. It’s a pretty hefty cost, especially since I upgraded to a more powerful but older server (more incentive for #3). Nowadays a VPS/Amazon EC2 instance can be had for under $20/month, running just about any OS, and with a better Internet connection than one could hope to have privately for the cost.
  5. Cancel personal smartphone. My workplace provides me with a smartphone. When I started, it was a BlackBerry 8830 World Edition, which was super cool – until the iPhone was launched. Since then I’ve switched to an iPhone 4 for work and an HTC Sensation for personal use. Having two phones is great (more on that later) – and I CHOOSE to have 2 phones, either one could do both work and play – thank you very much SAMSUNG. (God do I ever hate those commercials. And TouchWiz. And their poor quality control. And all the cheap plastic and gaudy designs.  I could go on for a while…) Long story short, consolidate on one device, save space in pockets, save <$50/month.
  6. Last but not least, stop buying random crap. I love technology. I love fixing things. I love learning and challenging myself. But at some point, keeping old computers to repair and experiment with Linux can go too far. Like a banker’s box full of possibly working laptops too far.

We’ll see how this goes over the next few months.

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