Add log if ES is unreachable

[pedrorijo91]

If ES is down, we were swallowing the exception. Now we at least log it as an error. Not sure if we have warnings at heroku level (@peff ), but if we don't, it won't hurt

closes #1001

[peff]

Wouldn't the exception eventually make it all the way to the top-level and cause Rails to dump a backtrace to the log (and a 500 to the user)?

But if we're not logging it currently, I'm not at all opposed to doing so. We don't keep the logs themselves for very long, and there's far too much volume to probably want to keep them all. But every once in a while capture a snapshot with heroku logs -t if I'm actively debugging something.

[pedrorijo91]

Wouldn't the exception eventually make it all the way to the top-level and cause Rails to dump a backtrace to the log (and a 500 to the user)?

but do we want to provide 500 for the user?

[peff]

but do we want to provide 500 for the user?

What should we provide? The only other obvious answer is an empty search result, but I wonder if a 500 makes more sense from the point of caching (i.e., it really is a server error, and if they try again in a minute they're going to get a different answer). I doubt it matters much in practice, though.

[pedrorijo91]

sure, I can make the exception bubble up. Will do that this weekend probably

[pedrorijo91]

it seems some tests broke. will need to take care of that

[pedrorijo91]

finally got some time to look into the failing tests, and I'm not sure of the best approach:

1. change the test/test_helper.rb file to stub any possible missing call - I'm not even 100% sure what's this file doing
2. mock the Doc.search and Section.search methods (which will call the elastic API):

  test "should get search page" do
    allow(Doc).to receive(:search).with(any_args).and_return([])
    allow(Section).to receive(:search).with(any_args).and_return([])

    get :search, search: "git-rebase"
    assert_response :success
  end

but this will return Minitest::UnexpectedError: NoMethodError: undefined method allow' for #SiteControllerTest:0x00007f8288fcd930`, which makes me think I'm missing some import.

But if I add require "rails_helper" on top of the test/functional/site_controller_test.rb file, I get 'require': cannot load such file -- rails_helper (LoadError)

I'm pretty sure I'm doing some rails-noob mistake here. Any hints @peff / @tarebyte ?