http plugin: no span attributes when http.get() throws

[blumamir]

What version of OpenTelemetry are you using?

v0.9.0

What version of Node are you using?

v13.11.0

What did you do?

instrumented http module with @opentelemetry/plugin-http. then called http.get(url, options, cb) with invalid header which caused the function to throw an exception.

If possible, provide a recipe for reproducing the error.

import { NodeTracerProvider } from "@opentelemetry/node";
import { SimpleSpanProcessor } from '@opentelemetry/tracing';
import { JaegerExporter } from '@opentelemetry/exporter-jaeger';

const provider = new NodeTracerProvider({
    logger: console
});

const exporter = new JaegerExporter({
    logger: console,
    serviceName: 'http-out-debug'
});
provider.addSpanProcessor(new SimpleSpanProcessor(exporter));
provider.register();

import * as http from 'http';
http.get('http://www.google.com', {
    headers: {
        cookie: undefined, // <============ this make http.get throw
    }
},
(res) => {

    res.setEncoding('utf8');
    let rawData = '';
    res.on('data', (chunk) => { rawData += chunk; });
    res.on('end', () => {
        console.log('got back data');
    });

});

What did you expect to see?

Http span with error, and relevant attributes (at least http.url).

What did you see instead?

Http span with error, but http.url and other request attributes missing in the span.

Span {
  attributes: {
    component: 'http',
    'http.error_name': 'TypeError',
    'http.error_message': 'Invalid value "undefined" for header "cookie"'
  },
  links: [],
  events: [],
  status: { code: 2, message: 'Invalid value "undefined" for header "cookie"' },
  endTime: [ 1593439010, 94328504 ],
  _ended: true,
  _duration: [ 0, 3152474 ],
  name: 'GET /',
  spanContext: {
    traceId: '414aa171b3c5cd00539a0d86ea7ab5b8',
    spanId: '6b1e1761ee041018',
    traceFlags: 1,
    traceState: undefined
  },
  parentSpanId: undefined,
  kind: 2,
  startTime: [ 1593439010, 91176030 ],
  resource: Resource {
    labels: {
      'telemetry.sdk.language': 'nodejs',
      'telemetry.sdk.name': 'opentelemetry',
      'telemetry.sdk.version': '0.9.0'
    }
  }
}

Additional context

When there are a lot of requests, and some requests fails due to bad header, the trace is missing important attributes which can be used to debug the issue (like http.url)
This is because getOutgoingRequestAttributes is called after the original patched function call.
I suggest to move getOutgoingRequestAttributes before original.apply, so span will contain url and other attributes if original.apply throw.