Updating the Core Software
with Joe Shindelar This tutorial covers how
to update the core software using the administrative
interface or with Drush. By the end of this tutorial, you'll know how
to update the core software either through
the administrative interface or by using Drush commands. If you want to use Drush
to perform the update, you'll need to make sure
that Drush is installed first. It's also a good idea
to test this process on a development
version of your site. If you haven't already,
now would be a good time to create a development
version of your site. See the written
version of this tutorial for links to
each of the prerequisites. At a high level, the steps
involved are as follows: 1, make a backup just in case
anything goes wrong. 2, put your site
into maintenance mode. 3, update the
core software's code to the latest version. 4, run the
database update script. 5, take the site
out of maintenance mode. And 6, clear
the cache for good measure. Let's walk
through an example. First, make a
complete backup of your site. In this case,
I've made a backup using the MySQL dump command and created this sql.gz file, which is all of the
database content for my site, as well as a
zip of the directory that contains all of the code that I'm going
to be updating and replacing. In order for
these updates to work, you'll need to be either
logged in as a user with the Administer
Software Updates permission, or you can open
the settings.php file under Sites, Default,
settings.php. In the settings.php file,
scroll down until you find the line
$settings["update_free_access"]. Like so. Which, for security reasons,
is set to False by default. As needed,
you can temporarily change the setting to True, which overrides the
need to be logged in when performing updates. I can change that here. The next thing that
you'll want to consider is temporarily disabling
any caching technique your application
might be using, like Varnish or Memcache, just to ensure that
they don't get in the way while performing an update. Then, put your site
in maintenance mode. That can be done by
clicking on Configuration and then under Development, Maintenance mode, and checking the box for
Put site into maintenance mode, and clicking
Save configuration. The next step is to
download the updated code. At this point, you've
got to make a decision. If you're managing your
site's files with Composer, you'll want to use Composer
to get the updated files. This is covered
in another tutorial. If you are not using Composer, you'll need to manually download
the code from Drupal.org. In previous
versions of Drush, you could use drush dl
to download Drupal core, but that is
no longer an option in current versions of Drush. To download it from Drupal.org, navigate to Drupal.org and then
click Download & Extend, select the current
version of Drupal Core, and then click to download either the tar.gz
or the zip file for the latest version. Once you've done that, you can extract it
into a temporary directory. And then you need to copy
all the appropriate files from this new code
that you just downloaded over the code that
currently makes up your site. Let's go ahead and do that. Be aware of hidden files. Things like the .htaccess file
that comes with Drupal Core are important to update as well. I'll start by
first removing the code from my existing site
that I no longer need, which is everything that
I haven't customized. In this case, that's all the
files and folders, excluding the modules,
sites and themes directory. I'll leave those as is because
they contain my customizations. I can come over here and grab
all of the updated code except for the modules,
sites and themes directory. And then I can come over here
in the code that I just downloaded and grab all the updated files except the ones
that I don't need, modules,
sites and themes, and place those
into my directory here of my existing site, basically just updating all of the code
with the latest version. Once you've completed that
step of updating the code, you need to run
the database update script. Note that if you use
Composer to manage your files, you'll pick back up here
in the update process. You can run the updates
in 1 of 2 ways. Either by visiting the update.php script
in your browser. Once there, you can
click the Continue button. It'll list any pending
database updates that you could review
if you would like. And then click
Apply pending updates. Once completed,
you'll get a list of all of
the successful updates. If you get any
errors or warnings, you can re-run
the update script again until all of the updates have
been completed successfully. Alternatively,
if you're using Drush, you can run the
drush updb command, which will do the same thing, run the
database update scripts. Once that's complete, if you changed the
settings.php file earlier, you'll need to
revert that now. Open settings.php
in your editor, and change the
"update_free_access" line back from TRUE to FALSE. Then, back on your site, you can take your site
out of maintenance mode. Click on Administration pages. That takes you back to your site. You'll see the message here that you're operating
in maintenance mode. You can click Go online, take the site out
of maintenance mode, and finally,
to verify that it worked, you can navigate to Reports
and then Status report and confirm that you're
running the latest version of the core software. In this tutorial, we learned how to
upgrade the core code after a security update
either manually or via Drush, as well as how to run
the database update script, in order to keep our site
up-to-date and secure.
