...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...
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...
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
...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...
In a nutshell: Use git rebase --onto target-branch source-commit target-branch means "branch you want to be based on" source-commit means "commit before your first feature commit...
...Let's say my-feature-branch is based on master and we want it to be based on production. Consider this history: %%{init: { 'gitGraph': {'showCommitLabel': true, 'mainBranchName': 'production'}} }%% gitGraph
...Doing that enables e.g. man in the middle attacks. If you accept only a single expired and known certificate, you are much less in trouble. Setup All the solutions described...
...below use a verify_callback for the request's OpenSSL::X509::Store where you can specify a lambda to adjust its verification response. Your callback must return either true or...
When you need to find out in which kind of spec you are during run-time, it's definitely possible. It's a lot easier in RSpec 2+.
...consider this global before block where you'd want to run some code for specific specs only: config.before do # stuff that_fancy_method # more stuff end RSpec 2+
...maintain. There are some good practices for writing a changelog that adds value, please stick to these. Add a notice to the README's contribute section about the changelog
...this project will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html). ## Unreleased - Added `Foo#foo` method. ## 1.0.0 - 2017-06-20 ### Breaking changes - Renamed `Foo...
...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.
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...
...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...
...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...
...uses a "real" time zone or :local, and if config.active_record.time_zone_aware_attributes is set to false or not. With time zones configured, always use .current for Time, Date, and...
...which hold time zone information and Time.now only in those that run with the server's time. If you don't, bad things can and will happen. More information can...
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.
There are two ways a logout in SAML can happen: Service Provider (SP) initiated and Identity Provider (IDP) initiated logout. I'll explain how to implement both flows with devise...
...on logout and devise does not do that we get a Unsafe redirect to "https://some-idp.example.com/realms/dev/protocol/saml?SAMLRequest=fZJBb9QwEIX%2FSm45zcZx4j...", pass allow_other_host: true to redirect anyway. upon trying to logout.
Here is how to use Chromedriver without libraries like selenium-webdriver. This can be useful for debugging. The following example visits a web page and reads the a headline's...
...things you can do with it, but performing more advanced tasks without a tool like selenium-webdriver can be quite difficult. However, for simple debugging or remote-controlling, curl might...
PostgreSQL can cosplay as a full-text search engine. It doesn't have the features or fidelity of ElasticSearch or Algolia, but it's good enough if you just need...
...to search and rank large volumes of text. This card will teach you how to index, search and rank your Rails models in a PostgreSQL full-text index. We will...
Get an idea of the varying support for HTML/CSS/JavaScript features in different browsers like Chrome, Firefox, Internet Explorer, Edge, Safari. Look up a few modern features like "subgrid", ":has...
...Understand how we test for older browsers using BrowserStack Ask a colleague for our shared BrowserStack credentials What are "Evergreen browsers"? Understand which browsers you are supposed to support in...
...a minifier that is good enough for most cases. If you're looking to squeeze out as many bytes as possible, you can consider compressing with Terser instead.
...will increase your build times significantly, but produce the smallest output: Terser (3 pass) Terser (1 pass) esbuild application.js 163.6 kB 163.7 kB 181.6 kB application.js (gzipped)
...and autoload paths. They do NOT create a module for namespacing. This is intuitive, since there normally is no module Model, or module Controller. If you want to add a...
├── models ├── uploaders # No config needed ├── util # No config needed └── workers # No config needed Sometimes it's handy to group files within a directory, but not reflect that grouping within...
Flash movies (.swf files) can talk with Javascript code embedded in the same HTML page. There are two ways to do this: The preferred way is to use the ExternalInterface...
...ActionScript by calling SetVariable(name, value) on the Flash movie's DOM element. This is super-legacy, but still encountered in the field. Note that communication between a Flash movie...
When your application is open for public sign up and sends out transactional e-mails to a large number of users, e-mail deliverability becomes an issue. E-mail providers...
...work hard to eliminate spam and have put in place relatively tight checks what kinds of emails they will accept, and from whom. To that end we use tools like...
...with an english name. This makes you code easier to read and is also suggested by Rubocop's Style/GlobalVars cop. Example before: if 'foo' =~ /foo/ puts $~[1] # => foo end
...following content: require 'English' List of global aliases $ERROR_INFO => $! $ERROR_POSITION => $@ $FS => $; $FIELD_SEPARATOR => $; $OFS => $, $OUTPUT_FIELD_SEPARATOR => $, $RS => $/ $INPUT_RECORD_SEPARATOR => $/ $ORS => $\ $OUTPUT_RECORD_SEPARATOR => $\ $INPUT_LINE_NUMBER...