Technical recipes for frequently and infrequently recurring problems
In production, exceptions that occur are sent to Honeybadger and are also logged with the standard Rails log which is sent to Splunk.
Blacklight (used in Hyrax) raises a RecordNotFound exception any time a record is not found in Solr. This is something that is very common when the site is being indexed by search engines.
A solution for this is to return a 404 instead of 500.
This commit has all the necessary code.
For all of our apps, you should add a route like this:
match '*path', via: :all, to: 'pages#error_404'
That route says that for any route that doesn’t exist send the request to a controller that will return a 404 response.
Then to handle the exception you’ll need to add Rack middleware to rescue the RecordNotFound exception:
class ExceptionMiddleware
def initialize(app)
@app = app
end
def call(env)
@app.call(env)
rescue Blacklight::Exceptions::RecordNotFound
# Redirect to non-existant location, which goes to the 404 page
[301, { 'Location' => '/not-found', 'Content-Type' => 'text/html' }, ['Moved Permanently']]
end
end
Instead of just ignoring the exception the request is redirected to
a location that will return a 404 because of the above route. Doing
it this way requires that you add the 404 route mentioned above.
To make additional exceptions reutrn a 404 you can copy that middleware, and
add it to the stack. This should only be done if the exception occuring
isn’t really exceptional. If a user or a bot requests a document that
doesn’t exist, a 404 is appropriate1.