tl;dr asdf allows you to manage multiple runtime versions with a single CLI tool and is backwards compatible by...
In Ruby on Rails ActiveRecord::Relation#merge overwrites existing conditions on the same column. This may cause the relation to...
I found the linked article very helpful to refresh my understanding of database indexes. As a small bonus, it includes...
Haml 6 was a major rewrite with performance in mind. To achieve a performance improvement of 1.7x, some design...
Usually you add errors to :base in ActiveRecord, in case no appropriate attribute could be used to add the error...
Maintaining larger projects makes it more difficult to balance refactoring and upgrade tasks according to its actual value. Consider to...
Let's say we have posts with an attribute title that is mandatory. Our example feature request is to tag...
In dieser Card machst du einige Übungsaufgaben um Linux Server mit Ansible zu verwalten. Da es vermutlich zu aufwendig ist...
This is a checklist I use to work on issues. For this purpose I extracted several cards related to the...
Rails partials have a lot of "hidden" features and this card describes some non-obvious usages of Rails Partials.
In the past we validate and set default values for boolean attributes in Rails and not the database itself.
HTTP header values must only contain low-ASCII (7-bit) characters for safe transport. From RFC 7230: Historically, HTTP has...
Not all email clients support external images in all situations, e.g. an image within a link. In some cases, a...
Carrierwave's BaseUploader can have some validations that you can use by overriding a certain method, which's expected name...
Das Standardtool für Monitoring auf AWS ist Cloudwatch. Du hast dir in den AWS Kapiteln Cloudwatch sicherlich schon grundsätzlich angesehen...
A severe bug was found in ImageMagick by Bryan Gonzalez from Ocelot Team. It allows to embed the content of...
Im Kapitel 502 Eine Applikation als Container mit CI pipelines deployen hast du eine Applikation auf AWS deployed. In diesem...
Let's assume that we have a model Movie that registers a callback function when a new instance of Movie...
When an object is created / updated, various callbacks are executed in this order: before_validation after_validation before_save
In diesem Kapitel wirst du eine Applikation in ein Containerimage verpacken und dieses via CI/CD bauen. Anschließend baust du die...
Kubernetes ist der de-facto Standard zum Orchestrieren von Container Workloads. Sowohl On Premise als auch in der Cloud wird...
In a Jasmine spec you want to spy on a function that is imported by the code under test. This...
In Puppet, there are some differences between defined and function types when it comes to code encapsulation. In most cases...
Du möchtest deinen AWS Account auf bestimmte Fehlkonfigurationen hin überwachen. Dafür wirst du AWS Config einsetzen. Über gebrochene AWS Config...