Rails 4.0 introduced a helpful new method for ActiveRecord queries: where.not. It can make clunky queries easier to read.
About Chrome's network stack and optimizations to load web pages faster...
Makes a robust determination of a user's timezone through Javascript.
How to make class_attribute behave like class_inheritable_attribte which no longer exists in Rails.
Chrome now supports desktop notifications using WebKit's webkitNotifications API. This means you can create popup bubbles from Javascript...
Ubuntu natty introduced new "invisible" scrollbars for GTK programs such as gEdit or Nautilus. If you do not like them: sudo apt-get purge liboverlay-scrollbar-* In order to have...
File upload solution that supports form roundtrips when a validation fails...
...least one external REST API, machine-to-machine communication via GraphQL is less commonly seen. In this card, I'd like to give a quick intro on how to query...
Interacting with GraphQL feels a bit like querying a local database. You are submitting queries to fetch data in a given structure (like SELECT in SQL) or mutations to...
...und bedienen im DevOps- & Cloud-Bereich primär Kunden, die ebenfalls auf Linux als Ziel-System setzen. Entsprechend benötigen wir tiefgehendes Wissen über Linux. In diesem Kapitel lernst Du alles zum...
...Hintergrund und ein wenig Theorie zu Prozessen, Speicher, Konfiguration und viel praktisches zur Konfiguration, Ressourcenüberwachung und abschließend eine Anleitung zur Performance-Analyse von Unix-basierten Systemen in 60 Sekunden.
...issues, depending on the exact version, and depending on your app. However, it is still possible to give some generic advice on how you want to tackle the update in...
...really confident about upgrading Rails, have a look at Rails LTS. How many update steps? Besides the Rails upgrade itself, you might also want to upgrade your other gems and...
Awesome battle report from Pinterest trying to scale their setup using different approaches. When you push something to the limit all technologies fail in their own special way. This lead...
...evaluate tool choices with a preference for tools that are: mature; really good and simple; well known and liked; well supported; consistently good performers; failure free as possible; free. Using...
Slow test suites are a major pain point in projects, often due to RSpec and FactoryBot. Although minitest and fixtures are sometimes viewed as outdated, they can greatly improve test...
We adopted a project using minitest and fixtures, and while it required some initial refactoring and establishing good practices, the faster test suite was well worth it! Stick with...
...or position: fixed display: inline-block display: table-cell overflow: (not "visible") and more, see https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Block_formatting_context Example: A fluid main area with a right sidebar
...you don't want either column to clear content of the other. Float the sidebar to the right and you're set: its content now renders in the sidebar's...
...exception of the currently running kernel, the kernel version that was installed on the system before that and, of course, the latest updated version of the kernel. However, it will...
...This could lead to unexpected removal of packages. So please check the output of sudo apt-get autoremove closely. One-shot, manual method sudo apt-get autoremove Automatically remove unused...
Phusion Passenger changed the way how it gets restarted several times. Through the project's history, these all were valid: touch tmp/restart.txt sudo passenger-config restart-app /path/to/app passenger-config...
gem 'capistrano-passenger', require: false Add to your Capfile: require 'capistrano/passenger' Declare which server role should be restarted (optional). Usually passenger tries to restart all servers with the app...
...exception, Rails will look at the exception's class and choose an appropriate HTTP status code and error page for the response. For instance, an ActiveRecord::RecordNotFound will cause Rails...
...render a red "The page you were looking for doesn't exist" with a status code of "404" (not found). The mapping from exception classes to error types is a...
How can I configure virtual IP's? There are two parameter to set up virtual ips in Keepalived: virtual_ipaddress Addresses defined here are included into the VRRP packets and...
...interface instead of the one in interface. Why are the floating IPs getting dropped by systemd-networkd/netplan? Read Prevent systemd from dropping IP-Addresses configured from other processes.
Why secure-only cookies used to be necessary Cookies have an optional secure flag. It tells the browser to not send the cookie for a non-https request.
...users from http:// to https://. The reason was that most users will only enter a scheme-less domain like makandra.de into their location bar, which will default to http://makandra.de...
Understanding your type of cronjob Some cronjobs must only run on a single server. E.g. when you run nightly batch operations on the database, it should probably run on a...
...single server. Running it on multiple servers would likely result in deadlocks or corrupt data. Some cronjobs must always run on all servers. E.g. starting a sidekiq process on reboot...
YourClass.reflect_on_all_associations.map(&:name) Get the class name by calling class_name, or the type of the association (belongs_to, has_many...
CarrierWave comes with a set of default configuration options which make sense in most cases. However, you should review these defaults and adjust for your project wherever necessary.
...also find suggestions on what to change below. Understanding the default configuration Here is the current default config for version 2: config.permissions = 0644 config.directory_permissions = 0755 config.storage_engines = { :file => "CarrierWave...
The following two hints are taken from Github's Ruby style guide: If your regular expression mentions a lot of forward slashes, you can use the alternative delimiters %r(...), %r...
...complex, you can use the /x modifier to ignore whitespace and comments: regexp = %r{ start # some text \s # white space char (group) # first group (?:alt1|alt2) # some alternation end
When browsing a repository, pressing "t" allows you to quickly search for file names. Very awesome! Go here to try it out...
...can reset the min-width. Say you have a simple grid layout: .container .first-item .second-item .third-item .container display: grid grid-template-columns: 100px 1fr 100px Your expectation...
...correct as the grid layout will try to do that: +---------+----------------------------+---------+ | | - 10 characters long | | +---------+----------------------------+---------+ However, if .second-item's content is too large to fit into the reserved space, it will...