Wrapping Legacy AngularJS App as "Business logic" from Rails

[epugh]

I wanted to share a spike using Ferrum for wrapping legacy Angular1 app to be run as a background job. Quepid, https://github.com/o19s/quepid, is a tool for testing your search engine. It has lots of custom code written in JS. I'm using Ferrum to run a Chrome instance and execute the logic, return the JSON data, and then I can process that.

Here is the in progress PR: o19s/quepid#976

Specifically, I'd love feedback on how I am using Ferrum in my run_case_job.rb. One issue I am noticing is that if I quit the browser via browser.quit then my Rails server quits! It appears to quit ruby, bringing down Rails...? So right now I have a @@browser object and just don't quit it. Would love any suggestions, feedback, pointers to others who have used Ferrum in a Rails app!

Plus, tell me if I am crazy!

[route]

The better question would be how you run your jobs? The code doesn't tell us how you run it.

[epugh]

The jobs are run using ActiveJob, backed by SideKiq.

My first attempt, with run_case_job.rb instantiates Ferrum and then loads the web page that has my legacy angular app: "http://localhost:3000/case/#{kase.id}/query/#{query.id}". In that page is some JSON that is the data I need that I then pull out and use. My second attempt, with run_case_job2.rb instead calls a Rails request handler, agent_q_controller.rb who then in turn instantiates Ferrum, calls the webpage with the legacy code, grabs the JSON data, and then returns that as the response from agent_q_controller.rb back to the calling ActiveJob run_case_job2.rb.

The first attempt is obviously a lot less cumbersome however I wasn't sure if Ferrum would quit and bring down ActiveJob too! I already had the agent_q_controller.rb so thought I would try that.

Right now however both ways periodically, say every 5 to 10 Ferrum calls, I then get a system exit, which then quits both my web and my worker processes.

[epugh]

Oh, also, I think that calling .quit on the browser also kills my Rails process??!

[route]

Let me rephrase it. what command do you run to run rails server and/or jobs server? Is this procfile and heroku? What platform do you use?

[epugh]

Thank you for the interest in my challenges ;-). Locally I run ferrum inside of a Docker container, and launch the web and worker processes using this procfile: https://github.com/o19s/quepid/blob/imagine_backend_batch/Procfile.dev. I do install my own Chromium in my Docker container: https://github.com/o19s/quepid/blob/imagine_backend_batch/Dockerfile.dev#L24.

[route]

That means that rails is a dedicated process with it's own PID, as well as sidekiq. Calling quit in sidekiq by any means can't kill rails process. Check out your memory, maybe it's OOM.