Use Faraday's URI util in Faraday context

[dalibor]

Inside FaradaySpy i.e. within the Faraday context we need to use the Faraday's URI utility, otherwise we get errors in the elastic-apm-ruby that did not fail in the Faraday code. Specifically, here's an example for when using Addressable::URI as Faraday's default_uri_parser:

Faraday::Utils.default_uri_parser = Addressable::URI.method(:parse)

Results:

>> URI('http://examplé.com')
Traceback (most recent call last):
        2: from (irb):14
        1: from (irb):15:in `rescue in irb_binding'
URI::InvalidURIError (URI must be ascii only "http://exampl\u00E9.com")

>> Addressable::URI.parse('http://examplé.com')
=> #<Addressable::URI:0x2245c URI:http://examplé.com>

>> Faraday::Utils.URI('from@examplé.com')
=> #<Addressable::URI:0x235a0 URI:http://examplé.com>

What does this pull request do?

Fixes an error in FaradaySpy.

Why is it important?

To fix errors in Elastic APM context.

Checklist

• I have signed the Contributor License Agreement.
• My code follows the style guidelines of this project (See .rubocop.yml)
• I have rebased my changes on top of the latest main branch

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

• I have made corresponding changes to the documentation
• I have updated CHANGELOG.asciidoc
• I have updated supported-technologies.asciidoc
• Added an API method or config option? Document in which version this will be introduced

Related issues

[dalibor]

@estolfo Could we get this one merged please?

[dalibor]

@picandocodigo Any chance we could get this one reviewed please?

[picandocodigo]

Hi @dalibor, I'll take a look at it. Is there a way we can reproduce the error in a test?

[dalibor]

@picandocodigo Thanks for looking into this. There are some details in the PR description, but basically I'm configuring Faraday to use Addressable::URI as its URI parser which works well with URLs that have Internationalized Domain Names (IDN) while URI standard library does not. And then I'm getting URI parsing error inside the ElasticAPM code i.e. inElasticAPM::Spies::FaradaySpy::Ext context that's external to the Faraday's run_request method.

I did some more investigation now and figured that this patch is not sufficient because it then fails at a later point inside ElasticAPM::Span::Context::Destination because ElasticAPM internally uses URI, so it fails at a different point.

I think I'll do URL sanitization on my side like the following:

>> uri = Addressable::URI.parse("http://examplé.com"); p uri; p URI.parse(uri.normalize.to_s); nil
#<Addressable::URI:0x3b1dc URI:http://examplé.com>
#<URI::HTTP http://xn--exampl-gva.com/>

Not sure if it makes sense for ElasticAPM to use Addressable::URI instead of URI? Ideally, ElasticAPM should not fail inside its spy context. It should handle its own failures and log a warning if that happens which is the issue here.

I will close this PR since I have a work-around and leave it to you if you want to do any of these two ideas. Thanks!