Upgrade to Ruby 2.4

[ysbaddaden]

• upgrade to Ruby 2.4;
• fix deprecations (Fixnum, OpenSSL);
• upgrade gems (to fix above deprecations);
• upgrade encryptor gem (fixing the algorithm to the previous aes-256-cbc default);
• re-enable the poirot-rails gem (we'll remove it in a dedicated PR);
• re-enable the aws-sdk gem (or just aws-sdk-s3);
• replace therubyracer gem with mini_racer (Upgrade to mini_racer gem #1791);
• push compatible branch to instedd/ruby-location_service and use it;
  • merge Support Ruby 2.4 + expect rspec syntax ruby-location_service#1
  • update Gemfile to use the merged commit
• bump loofah to 2.19.1 (Bump loofah from 2.15.0 to 2.19.1 #1827)
• bump rails-html-sanitizer to 1.4.4 (Bump rails-html-sanitizer from 1.4.2 to 1.4.4 #1829)
• Regression: investigate slow integration tests
• build the instedd/nginx-rails:2.4 Docker image rework production Dockerfile to be based on ruby:2.4 instead of instedd/nginx-rails.
• BUG: Sample label PDF pages are bleeding (the font is a little too big)c closes Improve performance of the print PDF actions #1723

refs #1792

[diegoliberman]

Let's wait until January to merge this, so that we send it to production when Julien is back from vacations.

[ysbaddaden]

Hum, the integration tests on CI seem to be much slower all of a sudden in this branch (main is unaffected). I'm investigating to see what's happening.

[ysbaddaden]

Selecting options is what's taking the most time in both Capybara & Cucumber specs. Each time it must select an option in a form, the browser hangs for a while, and I see the following message in the geckodriver log. It eventually continues but that inserts many hangs in the automated process that slows everything down (the rest feels normally fast).

Marionette      WARN    TimedPromise timed out after 500 ms

It may have something to do with the CdxSelect React component.

[ysbaddaden]

Further reduced: the hangup occurs when we click the .Select-placeholder selector in CdxSelect#set (and other methods). Finding the element is quick, but either the click is slow or the action of displaying the options (.Select-option) is super slow.

[ysbaddaden]

Found it: CdxSelect#select_elem is the source of the issue. We're searching for a parent element until .Select matches, which is taking over 2 seconds 😨

[ysbaddaden]

I added an optimization to avoid blindly looking for the element when it's already the element we expect (it matches .Select). It fixed the slow issue that appeared with the upgrades (Ruby & dependencies).

There are still lots of cases where the fallback to the slow path is required (which I tried to optimize a bit). Reviewing the matchers in Page Objects to directly attach CdxSelect to .Select elements may speed up the integration tests further.

[ysbaddaden]

@matiasgarciaisaia I reworked the production Dockerfile to be based on ruby:2.4 directly instead of instedd/nginx-rails:2.4.

The changes for deployments are:

• proxy target port is now 3000 (instead of 80)
• add the RAILS_SERVE_STATIC_FILES=1 environment variable

This is already done in staging.

[ysbaddaden]

The command actually starts whenever and puma processes. We might want to have a distinct container for whenever, like we do for sidekiq.

Alternative: use sidekiq-cron or sidekiq-scheduler instead.

[ysbaddaden]

Yeah, we're moving to Debian Buster (oldstable) 💪

[ysbaddaden]

BUG: the PDF is slightly different than on main. For example the CDx logo bleeds to other pages.

Generating the PDF relies on the abandoned and far outdated wkhtmltopdf binary through the wicked_pdf gem. A weird "webkit shrinking" mode is enabled by default and happens to behave differently depending on the wkhtmltopdf builds, despite using the exact same HTML source file.

After trying, unsuccessfully, to get a similar rendering, I chose to try out Prawn which proved as simple to use as ever and allowed to tweak the render to reach almost exactly the same render when zoomed at 400% (important because of dot matrix printer).