Migrating/Installing Prestashop to Amazon AWS EC2

Recently I migrated a Prestashop website to AWS/EC2 and the process is quite smooth. Here’s how to do it.

1. Get your Website data: including Prestashop website files and a latest database dump. Remove all the files except index.php in /cache/smarty/compile and /cache/smarty/cache. (See here.)

2. Launch your EC2 instance. But before doing that, check first if a pre-configured or managed Prestashop is available in your preferred region (more info here). If not, choose the appropriate instance type and get it running. In my case I chose Ubuntu Linux.

3. Install the AMP (Apache, MySQL and PHP). On Ubuntu you can simply do it with a few simple commands:

Make sure that you remember your password for MySQL root user and phpmyadmin user.

4. Copy your database dump and website files to your EC2 instance using scp, for instance:

5. Create a MySQL user for Prestashop, you don’t want to use the root user for this purpose. You can do this using phpmyadmin or a command line. Also, create a database for Prestashop and grant the user you’ve created just now all privileges on this database.

6. Import your database from the dump:

7. Extract your website files on your EC2 instance. In my case, inside /var/www/html/. If there is an index.html file inside this directory, remove it first. Make sure you set the correct user and group to all the website files:

Note that if don’t set the correct permissions, you may get complaints from Apache, like the following:

PHP Fatal error:  Uncaught exception ‘SmartyException’ with message ‘unable to write file /var/www/html/cache/smarty/compile/46/d9/69/wrt54ecd6c1856a72.61943173’ in /var/www/html/tools/smarty/sysplugins/smarty_internal_write_file.php:44

Stack trace:

#0 /var/www/html/tools/smarty/sysplugins/smarty_internal_template.php(201): Smarty_Internal_Write_File::writeFile(‘/var/www/html/c…’, ‘<?php /* Smarty…’, Object(Smarty))

#1 /var/www/html/tools/smarty/sysplugins/smarty_internal_templatebase.php(155): Smarty_Internal_Template->compileTemplateSource()

#2 /var/www/html/classes/controller/AdminController.php(1936): Smarty_Internal_TemplateBase->fetch(‘controllers/mod…’)

#3 /var/www/html/classes/controller/AdminController.php(2337): AdminControllerCore->initModal()

#4 /var/www/html/classes/controller/Controller.php(163): AdminControllerCore->init()

#5 /var/www/html/classes/Dispatcher.php(373): ControllerCore->run()

#6 /var/www/html/admin123/index.php(54): DispatcherCore->dispatch()

#7 {main}\n  thrown in /var/www/html/tools/smarty/sysplugins/smarty_internal_write_file.php on line 44

8. Enable mcrypt for PHP:

9. Update your Prestashop settings in the config/settings.inc.php file. Set the correct database information.

10. Enable mod_rewrite:

Also, make sure to add something like the following in your apache site configuration file:

And then remember to restart your apache server.

11. Install sendmail:

12. Go to your Prestashop back office and reconfigure your domain. Go to Preferences -> SEO & URLs and scroll down to Set shop URL section.

Now everything should be OK, your new Prestashop website is available on your new domain!

If you have any issues, just drop a line here or email me.

Raspberry Pi as a toy web server

1. Tell my router to route certain traffic to the Raspberry Pi. For example, I route HTTP and SSH traffic to one of my Pi’s. I disabled password login for  SSH, using public key authentication instead: in /etc/ssh/sshd_config, use the following setting and restart SSH service using `sudo service ssh restart’.

2. Getting my IP address of the Raspberry Pi. I firstly created a PHP script on my domain to record the IP address in a text file.

Then tell the Raspberry Pi to report its IP address every 5 minutes, using crontab:

After a while the IP address is recorded in the text file and updated every 5 minutes.

3. Optionally create a DNS record for the Pi. I use Cloudflare to manage DNS settings by myself, so just add/update an entry in Cloudflare’s settings. I point pi.daoyuan.li to the IP address of one Pi. This can be done automatically in the future.

4. Install Flask on the Pi.

5. Install nginx and uwsgi on the Pi.

6. Set up nginx along with uwsgi and Flask.

Edit nginx config:

Edit uwsgi config:

Create a simple Flask app:

Start up uwsgi:

7. Done! http://pi.daoyuan.li:5000/

 Update on June 24, 2014:

Getting the external address in step 2 can be done by running this command in Raspberry Pi:

See: http://www.commandlinefu.com/commands/view/5427/get-your-external-ip-address

Debugging Apache configuration files on Mac OS X

Sometimes I make some modification to my site’s apache config and apache stops functioning, but I cannot get enough information from /var/log/apache2/error.log. Here’s a command that will tell you where the problem is:

It starts apache for debugging and prints out the messages on screen, so that hopefully you can find something useful.

mod_wsgi and mod_xsendfile on OS X 10.9 Mavericks

Updated on Nov 4, 2013: The following tricks may still work, however I have found a much easier solution. Simply install Xcode command line developer tools and you should be able to compile source code without issues:

After upgrading my Mac from 10.8 to 10.9 Mavericks my apache stopped working, so I have to reinstall mod_wsgi and mod_xsendfile. However, tricks are needed to compile and install these mods successfully.

Upgrade Xcode

Upgrade Xcode in App Store. As mentioned by Valerie:

I had to manually upgrade Xcode (after Mavericks upgrade) from the App Store & agree to its license because ./configure hung forever until I did that.

mod_wsgi

For mod_wsgi installation, create a soft link to OSX10.9.xctoolchain:

Then run configure under mod_wsgi source code directory:

It will generate a Makefile similar as follows:

However, this Makefile is not correct and running ‘make’ the compiler will complain something like:

Prepend the following line to CPPFLAGS value:

Save the Makefile and it will look something like:

Then make && install:

Modify /etc/apache2/httpd.conf to enable mod_wsgi:

mod_xsendfile

Use the following command to compile and install mod_xsendfile:

Enabling HTTPS/SSL

After upgrading OS X the apache configuration was reset, but your original config is save to /etc/apache2/httpd.conf.pre-update. I need to enable SSL in httpd.conf again by uncommenting the following line:

Restart Apache and everything should work fine

Tastypie error handling with Unauthorized Exception

In Tastypie v0.9.15 unauthorized exception messages are not included in the response. The cause lies in the following code: (tastypie/resources.py, Line 601-602 in v0.9.15)

In the above snippet an empty response is returned, without including messages in exception.

In order to fix this, you can override this method in your model resources, for example:

Hi, the company I’m working for (yabroad.com) is hiring Website Backend and Frontend Developers to our platform team. We are building an open platform for youngsters to travel beyond boarders and we offer youngsters internship, language study, travel and volunteer opportunities. Please contact me if you are interested.

Upgrading Tastypie from v0.9.11 to v0.9.12 and above

Here are my notes on how to upgrade Tastypie from version 0.9.11 to 0.9.12, as there’re no release notes for v0.9.12. Release notes for 0.9.13 and above are available here: http://django-tastypie.readthedocs.org/en/latest/release_notes/index.html.

1. override_urls() becomes prepend_urls(), the new name makes more sense since what the function does is to insert customized urls instead of replacing the default urls with your customized urls.

2. obj_* methods accepts different parameters. Before:

Now obj_get, obj_create, etc. accepts bundle as the parameter apart from keyword arguments. You can get request object from the bundle:

3. apply_authorization_limits is no longer in use and it’s replace with a finer grained authorization mechanism. For example:

Please note that *_list methods should return a list or raise exceptions; whereas *_detail methods should return boolean values or raise exceptions. For more information, see: http://django-tastypie.readthedocs.org/en/v0.9.12/authorization.html

Hi, the company I’m working for (yabroad.com) is hiring Website Backend and Frontend Developers to our platform team. We are building an open platform for youngsters to travel beyond boarders and we offer youngsters internship, language study, travel and volunteer opportunities. Please contact me if you are interested.

Installing mod_xsendfile on OS X Lion

First download mod_xsendfile.c from https://tn123.org/mod_xsendfile/

Then compile and install it:

Add the following line to /etc/apache2/httpd.conf at the end of the first block of “Load” statements:

At last, restart the apache server

Hi, the company I’m working for (yabroad.com) is hiring Website Backend and Frontend Developers to our platform team. We are building an open platform for youngsters to travel beyond boarders and we offer youngsters internship, language study, travel and volunteer opportunities. Please contact me if you are interested.

Nothing is useless

Spring is already in Helsinki; I shot these beautiful flowers on the bus when going to work:

At work Aimmy invites us to have some cake during afternoon coffee break. The cake was very delicious and she’s really good at cooking yummy food. She has already made muffins twice before this; and we are all expected to taste some original Thai food, probably next week.

Yesterday I volunteered to set up a website for the project I’m currently working on. It seems that even my PHP skills will be useful for my career. Some skills developed from hobbies come quite handy when doing serious business. Everything, any experience or lessons are likely to be used sometime later…

I moved my desk to a different position in the room and now I’m enjoying the new layout. Last night I watched Hangover from my bed instead of siting in my uncomfortable chair, thanks to the new layout. 27 inch display looks OK and wireless keyboard acts as remote — a real big remote. Now off to watch Hangover 2. 🙂

首页上线

捣鼓了两三天,总算把自己这个域名的首页建好了,结束了长达四个月没有像样首页的状态。

首页用Joomla!系统管理,主要列出了我做过的项目和一些小玩意,目的只是为了展示自己,当然自己有几斤几两我是十分清楚的。所以请看过之后不必对我表示鄙视或者仰慕,但是如果有建设性的意见,我一定会欣然接受的。

Joomla!系统总体来说还是很不错的,容易上手,而且开源且支持扩展。目前来说易用性还有可改进的地方,但相信不久就会有相应的更新或者扩展来让它更加好用。

最近还在上瑞典语课,但这几天感觉没有什么进步,一直在复习以前学过的内容,而且课程组织的也没有上个月的好,甚至可以说是杂乱无章。我基本不知道现在在学习什么内容,比较痛苦的是现在词汇量还没有跟上,发音也没有系统的巩固。

中午在地铁站碰见上个月教我瑞典语的老太太,她上来第一句寒暄我就没有听懂。厚着脸皮说了句“Ursäkta?”老太太只好无奈的换成英文问候。

知不足而后进,所以这个周末我要好好补习一下,争取能有长足进展。