Technology Tales

Adventures & experiences in contemporary technology

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. What 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 by means of 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.

Command Line Processing of EXIF Image Metadata

8th July 2013

There is a bill making its way through the U.K. parliament at the moment that could reduce the power of copyright when it comes to images placed on the web. The current situation is that anyone who creates an image automatically holds the copyright for it. However, the new legislation will remove that if it becomes law as it stands. As it happens, the Royal Photographic Society is doing what it can to avoid any changes to what we have now. There may be the barrier of due diligence but how many of us take steps to mark our own intellectual property? For one, I have been less that attentive to this and now wonder if there is anything more that I should be doing. Others may copyleft their images but I don’t want to find myself unable to share my own photos because another party is claiming rights over them. There’s watermarking them but I also want to add something to the image metadata too.

That got me wondering about adding metadata to any images that I post online that assert my status as the copyright holder. It may not be perfect but any action is better than doing nothing at all. Given that I don’t post photos where EXIF metadata is stripped as part of the uploading process, it should be there to see for anyone who bothers to check and there may not be many who do.

Because I also wanted to batch process images, I looked for a command line tool to do the needful and found ExifTool. Being a Perl library, it is cross-platform so you can use it on Linux, Windows and even OS X. To install it on a Debian or Ubuntu based Linux distro, just use the following command:

sudo apt-get install libimage-exiftool-perl

The form of the command that I found useful for adding the actual copyright information is below:

exiftool -p “-copyright=(c) John …” -ext jpg -overwrite_original

The -p switch preserves the timestamp of the image file while the -overwrite_original one ensures that you don’t end up with unwanted backup files. The copyright message goes within the quotes along with the -copyright option. With a little shell scripting, you can traverse a directory structure and change the metadata for any image files contained in different sub-folders. If you wish to do more than this, there’s always the user documentation to be consulted.

WARNING: Engine XPORT does not support SORTEDBY operations. SORTEDBY information cannot be copied.

24th July 2012

When recently creating a transport file using PROC COPY and the XPORT library engine, I found the above message in the log. The code used was similar to the following:

libname tran xport "c:\temp\tran.xpt";

proc copy in=data out=tran;
run;

When I went seeking out the cause on the web, I discovered this SAS Note that dates from before the release of SAS 6.12, putting the issue at more than ten years old. My take on its continuing existence is that we still to use a transport file format that was introduced in SAS 5.x for sake of interoperability, both between SAS versions and across alternatives to the platform.

The SORTEDBY flag in a dataset header holds the keys used to sort the data and it isn’t being copied into the XPORT transport files, hence the warning. To get rid of it, you need to remove the information manually in data step using the SORTEDBY option on the DATA statement or using PROC DATASETS, which avoids rewriting the entire data set.

First up is the data step option:

data test(sortedby=_null_);
set sashelp.class;
run;

Then, there’s PROC DATASETS:

proc datasets;
modify test(sortedby=_null_);
run;
quit;

It might seem counterproductive to exclude the information but it makes no sense to keep what’s being lost anyway. So long as the actual sort order is unchanged, and I believe that the code that that below will not alter it, we can live with its documentation in a specification until transport files created using PROC CPORT are as portable as those from PROC COPY.

Creating waterfall plots in SAS using PROC GCHART

17th March 2012

Recently, I needed to create a waterfall plot couldn’t use PROC SGPLOT since it was incompatible with publishing macros that use PROC GREPLAY on the platform that I was using; SGPLOT doesn’t generate plots in SAS catalogs but directly creates graphics files instead. Therefore, I decided that PROC GCHART needed to be given a go and it delivered what was needed .

The first step is to get the data into the required sort order:

proc sort data=temp;
by descending result;
run;

Then, it is time to add an ID variable for use in the plot’s X-axis (or midpoint axis in PROC GCHART) using an implied value retention to ensure that every record in the dataset had a unique identifier:

data temp;
set temp;
id+1;
run;

After that, axes have to be set up as needed. For instance, the X-axis (the axis2 statement below) needs to be just a line with no labels or tick marks on there and the Y-axis was fully set up with these, turning the label from vertical to horizontal as needed with the ANGLE option controlling the overall angle of the word(s) and the ROTATE option dealing with the letters, and a range declaration using the ORDER option.

axis1 label=none major=none minor=none value=none;
axis2 label=(rotate=0 angle=90 "Result") order=(-50 to 80 by 10);

With the axis statements declared, the GCHART procedure can be defined. Of this, the VBAR statement is the engine of the plot creation with the ID variable used for the midpoint axis and the result variable used as the summary variable for the Y-axis. The DISCRETE keyword is needed to produce a bar for every value of the ID variable or GCHART will bundle them by default. Next, references for the above axis statements (MAXIS option for midpoint axis and AXIS option for Y-axis) are added and the plot definition is complete. One thing that has to be remembered is that GCHART uses run group processing so a QUIT statement is needed at the end to close it at execution time. This feature has its uses and appears in other procedures too though SAS procedures generally are concluded by a RUN statement.

proc gchart data=temp;
vbar id / sumvar=result discrete axis=axis2 maxis=axis1;
run;
quit;

A little look at Windows 8

6th November 2011

It has been a little while but I have managed to set up a VirtualBox virtual machine in order to take a look at the Developer Preview of the next version of Windows, something that I and others continue to call Windows 8 though Microsoft has yet to confirm the name. When I tried the installation before, it failed on me but that may have been due to having an earlier release of VirtualBox on my machine at that time. 4.1.14 has a preset for Windows 8 and I also happened to notice that it can create virtual hard disks that can be used with competitors like VMWare, Parallels and Virtual PC too. It’s an interesting development but I am left wondering why you’d need to do that when VirtualBox runs on most platforms anyway.

To get back to Windows 8, the installation ran near enough without any intervention apart form stating the language you wanted to use, U.K. English in my case. Starting up the operating system gains you a lock screen that you need to get out of the way so you can log in. It can be dragged out of your way or you can double-click on it or use the carriage return key to get rid of it. Quite why someone thinks it’s a good extra is a little beyond me when a log in screen would suffice. Logging in gets you the new start menu or, as I prefer to think of it, screen. By default, there are a good few Metro apps installed though I decided to rid myself of most of them.

Regarding those apps, one irritation could be that there isn’t that obvious a way to switch away from them to something else. Thankfully, ALT+TAB does seem to work and it has the most instantaneous effect. Otherwise, using the Windows key or hovering over the bottom left corner of the screen to get the menu that brings up the start screen. From the PC user’s point of view, I could see this needing a little more thought because it took a little while for me to figure out what to do. Closing Metro apps isn’t an option either unless you resort to the Task Manager to do so. Microsoft appears to want to leave them open from the point at which you start them until the PC is shut down. It’s a design decision that leaves me unconvinced though, particularly when thoughts of rogue apps running riot on a system come to mind. Then, a stop button could be handy.

There is no start menu as we have come to know it anymore with the start screen replacing it. However, it is possible to limit what’s on there to the software that you use most often an rearrange panels as you’d like them to be. Apart from hosting shortcuts for starting applications, it also acts as a task switcher like the task bar in Windows 7 and there is one of those in Windows 8 too when you jump to the desktop; handily, there’s a panel for that too. Installing Firefox added a panel to the start screen so a little thought has gone into such a common situation and that’s just as well. Still, there’s more work to be done because, currently, there’s no way of changing the background colour of the start screen without resorting to a hex editor or third party tools. Still, you can pick your own picture for the lock screen so things are not all locked down on you.

A preview of IE 10 is included and, apart from the occasional artifact when displaying one of my websites, it seems to work well enough as does Windows Explorer. However, apart from these and a smattering of Metro apps, the Developer Preview does feel barer that previous versions of Windows. However, it does appear that applications like Notepad, PowerShell and the Command Prompt are on there but you need to search for these. That also means that you know about them too so I’d suggest a better way of browsing the applications that are available too. This is one of the weaknesses of Ubuntu’s Unity interface and you need to search in the Dash to find them. Just starting to type in the Metro start screen (and other screens too, it seems) in Windows does trigger the completion of a search box much like what happens in the GNOME Shell Activities screen on systems with GNOME 3. While it’s good to see good ideas being reused from elsewhere, Microsoft might do well to note that you still can browse lists of applications in GNOME 3 too.

Shutting down Windows 8 also seems to be more convoluted than is the case with Windows 7. Logging off and then powering off from the log in screen is one approach and that was my early impression from GNOME 3 too. With the latter, I later was to discover a status menu plugin that added in the option where it was accessible or that using ALT key when clicking the status menu when the plugin wouldn’t work would do what I needed. Without logging off from Windows 8, you can do a shut down using the sidebar that appears on selecting Settings from the menu that pops up on hovering near the bottom left corner of the start screen or the Start button of the task bar of the desktop. Then, look for the power icon and select what you need from the menu that clicking on this icon produces. Of course, you may find that the ALT+F4 key combination when issued while on a clean desktop is the cleanest of all.

All in all, the Developer Preview of the next release of Windows looks fairly usable. That is not to say that there aren’t things that need changing. Apart from this being an early sight of what may be coming to us Windows users, it isn’t unknown for Microsoft to roll back on a radical move to make it more palatable to the user community. After all, it has to watch how it treats the corporate market too. The strong possibility of there being alterations is one thought that needs to be shared with those who are inclined to be losing their tempers at the moment and I have comments with unpleasant language out there on the web (none of that here, please, by the way). As for me, I like to look ahead in order to be forewarned about what’s coming my way in the world of computing. What I have seen so far of the next Windows release is reassuring though there are roughnesses such as PC shutdown and Metro app switching but Microsoft cannot commit commercial suicide either so these have to be fixed. It seems that the world of Microsoft operating systems is in flux with the company’s keeping a firm eye on the world of mobile computing with tablets being a major concern. Others may disagree but I can see Windows 8 working well on conventional PC’s and that’s no bad thing.

Changing to CKEditor from FCKEditor for WordPress Content Editing

25th April 2011

The post editor that I have been using on my WordPress-powered outdoors blog has not been TinyMCE but FCKEditor. My use of that editor has meant that WordPress’ autosave and word counting features have not been available to me but that was my choice, as strange as it will sound to some. However, there have been times when I have missed the autosaving functionality and lost work. Since FCKEditor has been replaced by CKEditor, there are plugins available for adding that editor to WordPress’ administration interface. Recently, I got to replacing the old FCKEditor plugin with a newer CKEditor one and that has gained me post or page autosaving. The more cosmetic word counting feature is not active until a draft is manually saved but I can live with that. Other than that, the interface remains familiar with all (X)HTML tags on show in the source code view without any being hidden away from view like in WordPress’ implementation of TinyMCE. That isn’t to see that WordPress is doing something wrong but just that there are alternative way of doing things that are equally valid. After all, why would there be choices if there only ever was one right way to do anything?

Like any WordPress plugins, those replacing the default content editor in WordPress can be vulnerable to changes in the publishing platform and there is one of those in the pipeline for 3.2: a minimalist post/page editor that is billed as being non-distracting. That planned new feature is drawing inspiration from the likes of QuietWrite, where you can write content and transfer it over to WordPress or leave it where it was written. Even with bigger changes like this, my experience never has been that design decisions made for new WordPress releases have restricted to any great extent how I use the thing. That’s not to say that my usage hasn’t changed over time but I have felt that any decisions were mine to make and not all made for me. In that light, I can foresee CKEditor continuing to work on WordPress 3.2 but I’ll be doing some testing ahead of time to be sure that is the case.

Turning off the admin bar in WordPress 3.1

25th October 2010

Work on WordPress 3.1 is in full swing at the moment though I initially though that they were taking a little break after 3.0. From what I can see, many refinements are being made to the multi-blog functionality and behind-the-scenes work is ongoing on the administration screens too.

Another under-the-bonnet change has been to make WordPress less tied to MySQL since the possibility of dropping in support for an alternative such as PostgreSQL is now a reality even if it isn’t part of the default package. For now, it looks as if this is going to be plugin territory rather than default multi-database support though that may become a sensible development in the light of Oracle’s acquisition of MySQL and its sabre rattling with regard to Java patents. So far, the change to WordPress has affected my use of its database engine to power an offline version of my online photo gallery but a quick spot of code editing sorted that issue.

One more obvious alteration is going to be the addition of a WordPress.com style administration bar to the top of all content and administration screens for a user who is logged into the system. It is going to be turned on by default but there will be the option of turning it off for those among who prefer things that way. All that will be needed for this is to add the following line near the top of wp-config.php:

define( “WP_SHOW_ADMIN_BAR”, false);

The chance to see new additions like those above and be ready for is my main reason for following WordPress development. It’s best to be ready than surprised though it has to be said that the blogging or CMS platform is a very polished one these days.

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