Otel span mapping uses `HTTP_TARGET`, which may be wrong

[mydea]

I just noticed that in our mapping of otel spans -> sentry spans, we have the logic:

const httpTarget = attributes[SemanticAttributes.HTTP_TARGET];
const httpRoute = attributes[SemanticAttributes.HTTP_ROUTE];

// Ex. /api/users
const httpPath = httpRoute || httpTarget;

However, I just ran some experiments, and noticed that the target is always just the path of the request, even if it goes to an external URL:

 http.request('http://example.com?what=true#hahaha', (httpRes) => {
    httpRes.on('data', () => {});
    httpRes.on('end', (d) => {
      res.send({ version: "v2" });
    });
  }).end();

Results in a span:

{
  'http.url': 'http://example.com/?what=true',
  'http.method': 'GET',
  'http.target': '/?what=true',
  'net.peer.name': 'example.com',
  'http.host': 'example.com:80',
  'net.peer.ip': '93.184.216.34',
  'net.peer.port': 80,
  'http.response_content_length_uncompressed': 1413,
  'http.status_code': 200,
  'http.status_text': 'OK',
  'http.flavor': '1.1',
  'net.transport': 'ip_tcp'
}

and:

app.get("/test-2", function (req, res) {
  http.request('/test-3', (httpRes) => {
    httpRes.on('data', () => {});
    httpRes.on('end', (d) => {
      res.send({ other: 123 });
    });
  }).end();
});

results in:

{
  'http.url': 'http://localhost/test-3',
  'http.method': 'GET',
  'http.target': '/test-3',
  'net.peer.name': 'localhost',
  'http.host': 'localhost:80',
  'http.error_name': 'Error',
  'http.error_message': 'connect ECONNREFUSED 127.0.0.1:80'
}

So I think we have to use the http.url instead of http.target? I don't see a good way to know programmatically that you are making a request to your own host, sadly, but maybe somebody has a good idea?