TOPIC: WEB SERVER
Moving a website from shared hosting to a virtual private server
24th November 2018
This year has seen some optimisation being applied to my web presences, guided by the results of GTMetrix scans. It was then that I realised how slow things were, so server loads were reduced. Anything that slowed response times, such as WordPress plugins, got removed. Usage of Matomo also was curtailed in favour of Google Analytics, while HTML, CSS and JS minification followed. Something that had yet to happen was a search for a faster server. Now, another website has been moved onto a virtual private server (VPS) to see how that would go.
Speed was not the only consideration, since security was a factor too. After all, a VPS is more locked away from other users than a folder on a shared server. There also is the added sense of control, so Let's Encrypt SSL certificates can be added using the Electronic Frontier Foundation's Certbot. That avoids the expense of using an SSL certificate provided through my shared hosting provider, and a successful transition for my travel website may mean that this one undergoes the same move.
For the VPS, I chose Ubuntu 18.04 as its operating system, and it came with the LAMP stack already in place. Have offload development websites, the mix of Apache, MySQL and PHP is more familiar to me than anything using Nginx or Python. It also means that .htaccess files become more useful than they were on my previous Nginx-based platform. Having full access to the operating system using SSH helps too and should mean that I have fewer calls on technical support since I can do more for myself. Any extra tinkering should not affect others either, since this type of setup is well known to me and having an offline counterpart means that anything riskier is tried there beforehand.
Naturally, there were niggles to overcome with the move. The first to fix was to make the MySQL instance accept calls from outside the server so that I could migrate data there from elsewhere, and I even got my shared hosting setup to start using the new database to see what performance boost it might give. To make all this happen, I first found the location of the relevant my.cnf configuration file using the following command:
find / -name my.cnf
Once I had the right file, I commented out the following line that it contained and restarted the database service afterwards, using another command to stop the appearance of any error 111 messages:
bind-address 127.0.0.1
service mysql restart
After that, things worked as required and I moved onto another matter: uploading the requisite files. That meant installing an FTP server, so I chose proftpd since I knew that well from previous tinkering. Once that was in place, file transfer commenced.
When that was done, I could do some testing to see if I had an active web server that loaded the website. Along the way, I also instated some Apache modules like mod-rewrite using the a2enmod command, restarting Apache each time I enabled another module.
Then, I discovered that Textpattern needed php-7.2-xml installed, so the following command was executed to do this:
apt install php7.2-xml
Then, the following line was uncommented in the correct php.ini configuration file that I found using the same method as that described already for the my.cnf configuration and that was followed by yet another Apache restart:
extension=php_xmlrpc.dll
Addressing the above issues yielded enough success for me to change the IP address in my Cloudflare dashboard so it pointed at the VPS and not the shared server. The changeover happened seamlessly without having to await DNS updates as once would have been the case. It had the added advantage of making both WordPress and Textpattern work fully.
With everything working to my satisfaction, I then followed the instructions on Certbot to set up my new Let's Encrypt SSL certificate. Aside from a tweak to a configuration file and another Apache restart, the process was more automated than I had expected, so I was ready to embark on some fine-tuning to embed the new security arrangements. That meant updating .htaccess files and Textpattern has its own, so the following addition was needed there:
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
This complemented what was already in the main .htaccess file, and WordPress allows you to include http(s) in the address it uses, so that was another task completed. The general .htaccess only needed the following lines to be added:
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.assortedexplorations.com/$1 [R,L]
What all these achieve is to redirect insecure connections to secure ones for every visitor to the website. After that, internal hyperlinks without https needed updating along with any forms so that a padlock sign could be shown for all pages.
With the main work completed, it was time to sort out a lingering niggle regarding the appearance of an FTP login page every time a WordPress installation or update was requested. The main solution was to make the web server account the owner of the files and directories, but the following line was added to wp-config.php as part of the fix even if it probably is not necessary:
define('FS_METHOD', 'direct');
There also was the non-operation of WP Cron and that was addressed using WP-CLI and a script from Bjorn Johansen. To make double sure of its effectiveness, the following was added to wp-config.php to turn off the usual WP-Cron behaviour:
define('DISABLE_WP_CRON', true);
Intriguingly, WP-CLI offers a long list of possible commands that are worth investigating. A few have been examined, but more await attention.
Before those, I still need to get my new VPS to send emails. So far, sendmail has been installed, the hostname changed from localhost and the server restarted. More investigations are needed, but what I have not is faster than what was there before, so the effort has been rewarded already.
Relocating the Apache web server document root directory in Fedora 12
9th April 2010
So as not to deface anything that is available online on the web, I have a tendency to set up an offline Apache server on a home PC to do any tinkering away from the eyes of the unsuspecting public. Though Ubuntu is my mainstay for home computing, I do have a PC with Fedora installed, and I have been trying to get an Apache instance to start automatically on there unsuccessfully for a few months. While I can start it by running the following command as root, I'd rather not have more manual steps than is necessary.
httpd -k start
The command used by the system when it starts is different and, even when manually run as root, it failed with messages saying that it couldn't find the directory while the web server files are stored. Here it is:
service httpd start
The default document root location on any Linux distribution that I have seen is /var/www and all is very well with this, but it isn't a safe place to leave things if ever a re-installation is needed. Having needed to wipe /var after having it on a separate disk or partition for the sake of one installation, it doesn't look so persistent to me. In contrast, you can safeguard /home by having it on another disk or in a dedicated partition, which means that it can be retained even when you change the distro that you're using. Thus, I have got into the habit of having the root of the web server document root folder in my home area, and that is where I have been seeing the problem.
Because of the access message, I tried using chmod and chgrp, but to no avail. The remedy has to do with reassigning the security contexts used by SELinux. In Fedora, Apache will not work with the context user_home_t that is usually associated with home directories, but needs httpd_sys_content_t instead. To find out what contexts are associated with particular folders, issue the following command:
ls -Z
The final solution was to create a user account whose home directory hosts the root of the web server file system, called www in my case. Then, I executed the following command as root to get things going:
chcon -R -h -t httpd_sys_content_t /home/www
It appears that even the root of the home directory has to have an appropriate security context (/home has home_root_t so that might do the needful too). Without that, nothing will work, even if all is well at the next level down. The switches for chcon command translate as follows:
-R : recursive; applies changes to all files and folders within a directory.
-h : changes apply only to symbolic links and not to where they refer in the file system.
-t : alters context type.
It took a while for all of this stuff about SELinux security contexts to percolate through to the point where I was able to solve the problem. A spot of further inspiration was needed too and even guided my search for the information that I needed. It's well worth trying Linux Home Networking if you need further details. Though there are references to an earlier release of Fedora, the content still applies to later versions of Fedora to the current release, if my experience is typical.
The wonders of mod_rewrite
24th June 2007
When I wrote about tidying dynamic URL's a little while back, I had no inkling that that would be a second part to the tale. My discovery of mod_rewrite, an Apache module that facilitates URL translation. The effect is that one URL is presented to the user in the browser address bar, and the very same URL is also seen by search engines, while another is passed to the server for processing. Though it might sound like subterfuge, it works very well once you manage to get it set up properly. While the web host for my hillwalking blog/photo gallery has everything configured such that it is ready to go, the same did not apply to the offline Apache 2.2.x server that I have going on my own Windows XP box. There were two parts to getting it working there:
- Activating mod-rewrite on the server: this is as easy as uncommenting a line in the
httpd.conffile for the site (the line in question is:LoadModule rewrite_module modules/mod_rewrite.so). - Ensuring that the
.htaccessfile in the root of the web server directory is active. You need to set the values of theAllowOverridedirectives for the server root and CGI directories toAllso that.htaccessis active. Not doing it for the latter will result in an error beginning with the following:Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that. HavingRewriteRuledirective is forbiddenAllow from Allset for the required directories is another option to consider when you see errors like that.
Once you have got the above sorted, add this line to .htaccess: RewriteEngine On. Preceding it with an Options directive to ensure that FollowSymLinks and SymLinksIfOwnerMatch are switched on does no harm at all and may even be needed to get things running. That done, you can set about putting mod_write to work with lines like this:
RewriteRule ^pages/(.*)/?$ pages.php?query=$1
The effect of this is to take http://www.website.com/pages/input and convert it into a form for action by the server; in this case, that is http://www.website.com/pages.php?query=input. Anything contained by a bracket is assigned to the value of a system-named variable. If you have several bracketed sections, they are assigned to sequentially numbered variables as follows: $1 for the first, $2 for the second and so on. It's all good stuff when you get it going, and not only does it make things look much neater, but it also possesses an advantage when it comes to future-proofing too. Web addresses can be kept constant over time, even if things change behind the scenes. It means that any returning visitors will find what they saw the last time that they visited and surely must ensure good karma in the eyes of those all important search engines.