v2.15.0

• Added support for monitoring MongoDB queries with the new
  _integrations/nrmongo
  package.

  • Example application
  • Full godocs Documentation

• Added new method Transaction.IsSampled() that returns a boolean that
  indicates if the transaction is sampled. A sampled transaction records a
  span event for each segment. Distributed tracing must be enabled for
  transactions to be sampled. false is returned if the transaction has
  finished. This sampling flag is needed for B3 trace propagation and
  future support of W3C Trace Context.

• Added support for adding B3
  Headers to outgoing requests.
  This is helpful if the service you are calling uses B3 for trace state
  propagation (for example, it uses Zipkin instrumentation). You can use the
  new
  _integrations/nrb3
  package's
  nrb3.NewRoundTripper
  like this:

  // When defining the client, set the Transport to the NewRoundTripper. This
  // will create ExternalSegments and add B3 headers for each request.
  client := &http.Client{
      Transport: nrb3.NewRoundTripper(nil),
  }
  
  // Distributed Tracing must be enabled for this application.
  // (see https://docs.newrelic.com/docs/understand-dependencies/distributed-tracing/enable-configure/enable-distributed-tracing)
  txn := currentTxn()
  
  req, err := http.NewRequest("GET", "http://example.com", nil)
  if nil != err {
      log.Fatalln(err)
  }
  
  // Be sure to add the transaction to the request context.  This step is
  // required.
  req = newrelic.RequestWithTransactionContext(req, txn)
  resp, err := client.Do(req)
  if nil != err {
      log.Fatalln(err)
  }
  
  defer resp.Body.Close()
  fmt.Println(resp.StatusCode)

Bug Fixes

• Fixed an issue where the
  nrgin
  integration was not capturing the correct response code in the case where no
  response body was sent. This issue has now been fixed but requires Gin
  greater than v1.4.0.