GitHub Actions: Retrying a failing step

If you have a flaky command you can use the nick-invision/retry to re-try a failing command, optionally with a timeout:

---
...
jobs:
  test:
    ...
    steps:
    - name: Run tests
      uses: nick-invision/retry@v2
      with:
        timeout_seconds: 30
        max_attempts: 3
        command: bundle exec rake spec

Run a script on the server

You have to specify the environment with -e env_name or RAILS_ENV=env_name if you want to run a script on the server.

at Rails 2 it's script/runner

bundle exec script/runner -e env_name path/to/script.rb argument1 argument2 ...

at Rails 3 it's rails runner

RAILS_ENV=env_name bundle exec rails runner path/to/script.rb argument1 argument2 ...

How to make sure that manual deploy tasks (scheduled in Pivotal Tracker) are executed on deploy (with Capistrano)

We regularly have tasks that need to be performed around a deploy. Be it to notify operations about changed application behavior, be it to run a little oneline script after the deploy. Most database-related stuff can be handled by migrations, but every once in a while, we have tasks that are much easier to be performed manually.

Writing deploy tasks

Here is how we manage the deploy tasks themselves:

  • Deploy tasks are written inside the Pivotal Tracker story description, clearly marked (e.g. with a headline "Deploy task")
  • We disting...

VCR and the webdrivers gem

If you're using the webdrivers gem and VCR together, depending on your configuration, VCR will yell at you regulary.
The webdrivers gem tries to update your webdrivers on your local machine. To do so, it checks the internet for newer versions, firing an HTTP-request to e.g. https://chromedriver.storage.googleapis.com

You can "fix" this in multiple ways:

  1. Update your drivers on your machine with
    RAILS_ENV=test rake webdrivers:chromedriver:update

  2. Ignore the driver update-URL in your ...

How to configure file watchers in RubyMine

Installation

You need to install the official plugin, it is not bundled with RubyMine by default.

Example: Setup a watcher to verify rubocop integrity

First, open Settings -> Tools -> File Watchers. Then, configure rubocop to check every change to the VCS:

Image

Note that the "program" argument must be part of your $PATH. I worked around this constraint by using b as a shim for bundle exec.

Resources

  • [File watchers documen...

Rails: Concurrent requests in development and tests

With puma you can have concurrent requests. There are two concepts on how Puma can handle two incoming requests: Workers and Threads.

Workers

Puma can have multiple workers. Each worker is a process fork from puma and therefore a very heavy instance and can have multiple threads, that handle the incoming requests.

Example: A Puma server with 2 workers and 1 thread each can handle 2 request in parallel. A third request has to wait until the thread of one of the workers is free.

Threads

Rails is thread-safe since version 4 (n...

Ubuntu: Fix "An error occurred while installing pg"

If you get an error like this:

An error occurred while installing pg (0.17.1), and Bundler cannot continue.
Make sure that gem install pg -v '0.17.1' succeeds before bundling.

Then do this:

sudo apt-get install libpq-dev

... and run Bundler again.

Running Rails 2 apps with modern MariaDB SQL server

You might have some trouble running a Rails LTS 2 app with MySQL 5.7.

If you don't want to hack Mysql 5.6 into your modern Ubuntu or use the MySQL sandbox, you might want to try MariaDB 10.x.

MariaDB 10.x should work with both old and new Rails applications.

[Switch to MariaDB](https://makandracards.com/makandra/468343-how-...

Using Solr with Sunspot

This describes all the steps you'll need to get Solr up and running for your project using the Sunspot gem.

Prepare Sunspot on your development machine

What you want in your Gemfile:

gem 'sunspot_rails'
gem 'sunspot_solr'
gem 'progress_bar' # for sunspot:solr:reindex

Now define what should be indexed within Solr from your ActiveRecord models, e.g.,

class Article << ActiveRecord::Base

  searchable do
    text :title
 ...

How to checkout submodules in Gitlab CI

Accessing other repositories in Gitlab CI is not straight forward, since the access rights of the current pipeline might not be sufficient enough.

One approach is to use project access tokens and clone the repositories via HTTPS.

  • Create a project access token for all submodules you want to have access to with the setting read_repository
  • Add the secrets as environment variable to the main project you want to have access to submodules:
    • Protected false ...

Cronjobs: "Craken" is dead, long live "Whenever"

Our old solution for cronjobs, the "craken" plugin, is no longer maintained and does not work on Rails 3.2+.

We will instead use the whenever gem.

"Whenever" works just like "craken", by putting your rake tasks into the server's cron table. Everything seems to work just like we need it.

Installation for new projects

  1. Add "whenever" to your Gemfile:

     group :deploy do
       gem 'whenever', require: false
     end
    
  2. Add it to your config/deploy.rb:
    ...

Sprites with Compass

Using CSS sprites for background images is a technique for optimizing page load time by combining smaller images into a larger image sprite.

There are ongoing arguments on how useful this still is, as modern browsers become more comfortable to load images in parallel. However, many major websites still use them, for example amazon, [facebook](...

Using local fonts with Webpack / Webpacker

When we want to use our own (or bought) fonts in an application with Webpack(er), we have two options. We can

  • put the fonts directly into your Webpack's assets folder or
  • write an npm package with an own sass file that can be imported from the Webpack manifest.

Load fonts from your assets folder

The first option turns out to be straightforward: Import the stylesheets in the index.js of the pack you're using:

// webpack_source_path/application/index.js

import './stylesheets/reset'
import...

Parallel cucumber: How to pass in cucumber arguments

Here is an example with the --tags option. You need to wrap them inside --cucumber-options option of parallel_cucumber.

DISPLAY=:17 bundle exec parallel_cucumber --cucumber-options '--tags @solo' features

See more details in the docs.

How to employ and run your tests with parallel_tests to speed up test execution

When your cucumber features grow massively over time, the test execution can take a lot of time.
One easy way to speed up your test execution is to use the parallel_tests gem.
It comes along with some useful rake tasks that let you setup your local test environment shortly to run your features, specs or unit-tests in parallel.

Follow these steps to get it to work.

  1. Add the parallel_tests gem to your Gemfile test sections like that:

    # ./Gemfile
    
    group :development, :test do
    

...

Upgrading Ruby from 1.8.7 to 2.3.5

Suggested Workflow

Set the ruby version in .ruby-version to 2.3.5, then perform these steps one by one, fixing errors as they occur:

  1. Update gems as listed below, and bundle
  2. Boot a Rails console - see below for a list of changes you will probably need
  3. Run Specs with --backtrace option
  4. Run Cucumber features (with Geordi's --debug option)
  5. When all tests are green, look through your Gemfile and remove as many version constraints as possible.
  6. Boot the application in different environements to spot further issues, e...

How to: Fix json 1.8.3 with Ruby 2.5

The gem json fails to install for Ruby 2.5 if you use a version equal or below 1.8.3.

Run bundle update json --conservative to solve this issue.

The backtrace you will encounter looks like this:

Building native extensions. This could take a while...
ERROR:  Error installing json:
	ERROR: Failed to build gem native extension.

    current directory: /home/user/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/json-1.8.3/ext/json/ext/generator
/home/user/.rbenv/versions/2.5.3/bin/ruby -I /home/user/.rbenv/versions/2.5.3/lib/ruby/si...

A few hints when upgrading to Ruby 1.9

Note: If you are currently working with Ruby 1.8.7 or 1.9.3, we recommend to upgrade to Ruby 2.1 first. From our experience this upgrade is much smoother than the jump from 2.1 and 2.2, while still giving your the huge performance gains of Ruby 2. Also, if you're on Ruby 1.8.7, we recommend to skip a troublesome upgrade to 1.9.3 and go straight to 2.1.


When trying to make a Rails app run on Ruby 1.9, you're likely to encounter several issues. Here are a few solutions (obviously not exhaustive):

When running `bundle ...

Plotting graphs in Ruby with Gruff

Geoffrey Grosenbach has created Gruff for easily plotting graphs. It is written in pure Ruby and integrates with Rails applications.

It provides features as automatic sizing of dots and lines (the more values, the thinner the graph's elements), custom or predefined themes, different styles (bar, line, dot and many more) and multiple graphs in one chart.

Installation

In your Gemfile:

gem 'rmagick', :require => false
gem 'gruff'

Then run bundle install (and don't forget to restart your development server.)

Usage

This i...

Installing therubyracer and libv8 with Ruby 1.8 on OSX Mavericks

There seems to be no way to use therubyracer -v '0.11.4' and libv8 -v '3.11.8.17' on OS X Mavericks.

However, running bundle update therubyracer worked for me. It installed therubyracer -v '0.12.1' and libv8 -v '3.16.14.3' and I had not side effects.


Log of my attempts to get it working

Probably you got here when bundling failed building native extensions for therubyracer.

The libv8 (3.3.10.4) should have been installed when bundling. Unfortunately it is not building correctly on Mavericks, so the libv8.a f...

chromedriver-helper gem in Gemfile might break you selenium tests (of other projects)

Summary: Don't add chromedriver-helper to the Gemfile

  • the executables might break your tests in projects where chromedriver-helper is not in the Gemfile
  • developers with different chrome versions will have problems using the same chromedriver-helper version

Background

If you install the chromedriver-helper gem, but don't have it in you Gemfile, your selenium tests might fail with:

Selenium::WebDriver::Error::WebDriverError: unable to connect to chromedriver 127.0.0.1:9515

The reason is that chromedriver-helper ov...

Edge Rider: Power tools for ActiveRecord scopes

In our continued quest to extract proven code snippets from makandropedia into tested and upgradable gems, we have released Edge Rider.

Edge Rider was created with two intents:

  1. Provides a number of utility methods to facilitate hardcore work with scopes.
  2. Provide a stable API for working with scopes across multiple versions of Rails, since Rails has a tradition of breaking details of its scope API every other release.

The gem bundles multiple patches and initializers we've been using for hard...

Installation of therubyracer fails with "undefined method `include_path'"

Today I ran into trouble installing therubyracer on Ruby 1.8. The installation failed with

*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
   ...