...manage to find the cause of this behaivour yet, but I think it has something to do with the start order of the nova services. (When nova-network isn't...
...present at nova-compute startup, no rules will be applied at all) You can restart the nova-compute service and nova should insert the rules one by one (you can...
The solution in this card is based on a stack overflow post by Leventix. If you need to make request come from a fixed IP address for the duration of...
...a Cucumber scenario, the code below lets you write this: Given my IP address is 188.174.117.205 Rails 3 Given /^my IP address is "(.*?)"$/ do |ip| ActionDispatch::Request.any_instance.stub(:remote_ip).and...
Rails supports time zones, but there are several pitfalls. Most importantly because Time.now and Time.current are completely different things and code from gems might use one or the other.
Your life will be easier if your application does not need to support time zones. Disable them like this: config.time_zone = 'Berlin' # Your local time zone config.active_record.default_timezone...
This looks like it is safe to use: 2.2.1 :001 > a = b = "hello world" "hello world" 2.2.1 :002 > a "hello world" 2.2.1 :003 > b "hello world" 2.2.1 :004 > b = " goodbye...
...happening when we do a = b = "hello world"? First, b is assigned to a String object "hello world", then a is assigned to b. a and b are now assigned...
...Thunderbird 3 put there. Though the CompactHeader addon is often claimed to be a solution it does way too much for me -- I like the headers the way they are...
...very well for me (keeps the date and "other actions" menu on the right, see the screenshot below): Open up your profile directory (~/.thunderbird/ /) Create a chrome directory inside it...
Here is a bash script that I use to auto-configure displays on Ubuntu 24.04 with Xorg. Background Ubuntu always sets the primary display to the 1st (i.e. internal) display...
...bottom-aligned (the default would be aligned at their top edges). As an oddly specific bonus (you may not need this), I adjust my internal display's resolution when connected...
...number of different versions for Ruby, Rails and many gems. To be able to switch between projects easily, we must control every dependency our applications has. Goals Understand what a...
...with their dependencies and version history. Bundler overview and workflow How to update a single gem conservatively: A major bundler caveat How to manage versions in a Gemfile
My RubyMine (and it seems like many other Java GUI applications) crashes the Compiz window decorator almost every time on exit. This also seems to happen for the Unity decorator...
...Update: The commited fix from below seems to have made it into the stable Ubuntu repository. Easy mode You can restore window decorations by executing this command: gtk-window-decorator...
The git doc states on the difference of these two commands: git-restore[1] is about restoring files in the working tree from either the index or another commit. This...
...The command can also be used to restore the content in the index with --staged, or restore both the working tree and the index with --staged --worktree. By default, if...
When you need test images, instead of using services like lorempixel or placehold.it you may generate test images yourself. Here we build a simple SVG image and wrap it into...
...a data: URI. All browsers support SVG, and you can easily adjust it yourself. Simply set it as an image's src attribute. JavaScript Simple solution in modern JavaScript, e.g...
Embedding videos on a website is very easy, add a tag to your source code and it just works. Most of the time. The thing is: Both the operating...
...an 0.x version and has quite some development dependencies. It has the Apache license. streamio-ffmpeg seems to be perfect, but had its last release in 2016. It offers...
Defining one callback several times in the same class behaves different in ActiveRecord and ResourceController. While in ActiveRecord the callbacks are enqueued, they overwrite each other in ResourceController. ActiveRecord - a...
...common practice class Post < ActiveRecord::Base does 'post/behavior' before_validation :do_something end module Post::BehaviorTrait as_trait do before_validation :do_something_else end end do_something_else and...
...is hard coded. A popular example is extension_allowlist, which returns an array of strings and let's you only upload files that have a filename with an extension that...
...matches an entry in that array. Another useful validation can be size_range, which gives you a little bit of control over how your storage gets polluted.
...consider processing your images with libvips instead of ImageMagick. Reasons for libvips There are several upsides to using libvips over ImageMagick: libvips is considerably faster and uses less memory.
...has a large attack surface that has repeatedly caused security incidents in the past (compare ImageMagick CVEs with libvips CVEs). Ubuntu is sometimes slow to fix the numerous ImageMagick vulnerabilities...
Most forms have a single submit button that will save the record when pressed. Sometimes a form needs additional submit buttons like "accept" or "reject". Such buttons usually attempt...
...a state transition while updating the record. To process a form with multiple buttons, your server-side code will need to know which button was pressed. To do so you...
Webmocks hash_including is similar to RSpec::Mocks::ArgumentMatchers#hash_including. Be aware that hash_including (webmock v3.0.1) doesn't parse integer values to String. Without hash including you would...
uri = URI('http://example.com/?foo=1&bar=2') stub_request(:get, 'example.com').with(query: {foo: 1, bar: 2}) Net::HTTP.get(uri) # ===> Success If you only want to check if foo is present...
View specs are a powerful tool to test several rendering paths by their cases instead of using a more costing feature spec. This is especially useful because they become quite...
...used with Capybara::Node::Finders and Capybara::RSpecMatchers. This allows to wirte view unit specs as you can isolate specific parts of the rendered view and then use readable and...
...However, you need to be aware of the overall transaction nesting constellation, because creating proper sub-transactions can lead to unwanted or too early triggering of after_commit callbacks:
...project> Country.first.name # => "Afghanistan will not change" Wait. What happened to the rollback in the after_save-callback? From the Rails docs: Transaction calls can be nested. By default, this makes...
Slides for Henning's talk on Sep 21st 2017. Understanding sync vs. async control flow Talking to synchronous (or "blocking") API print('script start') html = get('/foo') print(html)
Script outputs 'script start', (long delay), '...
...', 'script end'. Talking to asynchronous (or "evented") API print('script start') get('foo', done: function(html) { print(html) }) print('script end')
Any form fields where users enter numbers should be an . Numeric inputs have several benefits over : On mobile or tablet devices, number fields show a special virtual keyboard that shows...
...mostly digit buttons. Decimal values will be formatted using the user's language settings. For example, German users will see 1,23 for . Values in the JavaScript API or when...
In this card we will learn to write code that scales with a large number of database records. We will do this by pushing work out of Ruby and into...
...a scope of movies matching the following query format: The query is a list of space-separated words that all need to appear in the movie title for the movie...
...previously announced it would not charge royalties for such video through December 31, 2015 (see http://www.mpegla.com/Lists/MPEG%20LA%20News%20List/Attachments/226/n-10-02-02.pdf), and today’s announcement makes clear that royalties will continue not to...
...be charged for such video beyond that time. Products and services other than Internet Broadcast AVC Video continue to be royalty-bearing...
Shoulda Matchers don't provide canditional validations (validations with if: option). Here is how to write tests for the condition: Class: class Employee < ActiveRecored::Base validates :office, presence: true, if...
describe Employee do describe '#office' do context 'is a manager' do before { allow(subject).to receive(:manager?).and_return(true) } it { is_expected.to validate_presence_of(:office) } end context 'is...
Note: Consider using MATE instead of Gnome 3 on newer system Awesome is a very good tiling window manager that provides neat features like automatic layouting of windows, good multi...
Improve your font-rendering Copy /etc/xdg/awesome/rc.lua to ~/.config/awesome/rc.lua. Take a look, it's pretty self-explanatory. You can instantly apply changes by reloading Awesome with Meta-Ctrl-R.