drupal

Rendering Twig templates programmatically in Drupal 8

From time to time, I have the need to take a Twig template and a set of variables, render the template, replacing all the variables within, and then get the output as a string. For example, if I want to have a really simple email template in a custom module which has a variable for first_name, so I can customize the email before sending it via Drupal or PHP, I could do the following in Drupal 7:

Cleaning up after adding files in Drupal Behat tests

I've been going kind of crazy covering a particular Drupal site I'm building in Behat tests—testing every bit of core functionality on the site. In this particular case, a feature I'm testing allows users to upload arbitrary files to an SFTP server, then Drupal shows those filenames in a streamlined UI.

I needed to be able to test the user action of "I'm a user, I upload a file to this directory, then I see the file listed in a certain place on the site."

These files are not managed by Drupal (e.g. they're not file field uploads), but if they were, I'd invest some time in resolving this issue in the drupalextension project: "When I attach the file" and Drupal temporary files.

Since they are just random files dropped on the filesystem, I needed to:

Make composer operations with Drupal way faster and easier on RAM

tl;dr: Run composer require zaporylie/composer-drupal-optimizations:^1.0 in your Drupal codebase to halve Composer's RAM usage and make operations like require and update 3-4x faster.

A few weeks ago, I noticed Drupal VM's PHP 5.6 automated test suite started failing on the step that runs composer require drupal/drush. (PSA: PHP 5.6 is officially dead. Don't use it anymore. If you're still using it, upgrade to a supported version ASAP!). This was the error message I was getting from Travis CI:

PHP Fatal error:  Allowed memory size of 2147483648 bytes exhausted (tried to allocate 32 bytes) in phar:///usr/bin/composer/src/Composer/DependencyResolver/RuleWatchNode.php on line 40

I ran the test suite locally, and didn't have the same issue (locally I have PHP's CLI memory limit set to -1 so it never runs out of RAM unless I do insane-crazy things.

Deploying an Acquia BLT Drupal 8 site to Kubernetes

BLT to Kubernetes

Wait... what? If you're reading the title of this post, and are familiar with Acquia BLT, you might be wondering:

  • Why are you using Acquia BLT with a project that's not running in Acquia Cloud?
  • You can deploy a project built with Acquia BLT to Kubernetes?
  • Don't you, like, have to use Docker instead of Drupal VM? And aren't you [Jeff Geerling] the maintainer of Drupal VM?

Well, the answers are pretty simple:

Hosted Apache Solr now supports Drupal Search API 8.x-2.x, Solr 7.x

Earlier this year, I completely revamped Hosted Apache Solr's architecture, making it more resilient, more scalable, and better able to support having different Solr versions and configurations per customer.

Today I'm happy to officially announce support for Solr 7.x (in addition to 4.x). This means that no matter what version of Drupal you're on (6, 7, or 8), and no matter what Solr module/version you use (Apache Solr Search or Search API Solr 1.x or 2.x branches), Hosted Apache Solr is optimized for your Drupal search!

Hosted Apache Solr - version selection

Testing the 'Add user' and 'Edit account' forms in Drupal 8 with Behat

On a recent project, I needed to add some behavioral tests to cover the functionality of the Password Policy module. I seem to be a sucker for pain, because often I choose to test the things it seems there's no documentation on—like testing the functionality of the partially-Javascript-powered password fields on the user account forms.

In this case, I was presented with two challenges:

  • I needed to run one scenario where a user edits his/her own password, and must follow the site's configured password policy.
  • I needed to run another scenario where an admin creates a new user account, and must follow the site's configured password policy for the created user's password.

So I came up with the following scenarios:

Analyzing a MySQL slow query log with pt-query-digest

There are times when you may notice your MySQL or MariaDB database server getting very slow. Usually, it's a very stressful time, as it means your site or application is also getting very slow since the underlying database is slow. And then when you dig in, you notice that logs are filling up—and in MySQL's case, the slow query log is often a canary in a coal mine which can indicate potential performance issues (or highlight active performance issues).

But—assuming you have the slow query log enabled—have you ever grabbed a copy of the log and dug into it? It can be extremely daunting. It's literally a list of query metrics (time, how long the query took, how long it locked the table), then the raw slow query itself. How do you know which query takes the longest time? And is there one sort-of slow query that is actually the worst, just because it's being run hundreds of times per minute?

Running Drupal Cron Jobs in Kubernetes

There are a number of things you have to do to make Drupal a first-class citizen inside a Kubernetes cluster, like adding a shared filesystem (e.g. PV/PVC over networked file share) for the files directory (which can contain generated files like image derivatives, generated PHP, and twig template caches), and setting up containers to use environment variables for connection details (instead of hard-coding things in settings.php).

But another thing which you should do for better performance and traceability is run Drupal cron via an external process. Drupal's cron is essential to many site operations, like cleaning up old files, cleaning out certain system tables (flood, history, logs, etc.), running queued jobs, etc. And if your site is especially reliant on timely cron runs, you probably also use something like Ultimate Cron to manage the cron jobs more efficiently (it makes Drupal cron work much like the extensive job scheduler in a more complicated system like Magento).

Nginx serving up the wrong site content for a Drupal multisite install with https

I had a 'fun' and puzzling scenario present itself recently as I finished moving more of my Drupal multisite installations over to HTTPS using Let's Encrypt certificates. I've been running this website—along with six other Drupal 7 sites—on an Nginx installation for years. A few of the multisite installs use bare domains, (e.g. jeffgeerling.com instead of www. jeffgeerling.com), and because of that, I have some http redirects on Nginx to make sure people always end up on the canonical domain (e.g. example.com instead of www. example.com).

My Nginx configuration is spread across multiple .conf files, e.g.:

Real World DevOps

This blog post contains a written transcript of my NEDCamp 2018 keynote, Real World DevOps, edited to match the style of this blog. Accompanying resources: presentation slides, video.

Jeff Geerling at NEDCamp 2018 - New England Drupal Camp

I'm Jeff Geerling; you probably know that because my name appears in huge letters at the top of every page on this site, including the post you're reading right now. I currently work at Acquia as a Senior Technical Architect, building hosting infrastructure projects using some buzzword-worthy tech like Kubernetes, AWS, and Cloud.