Go Tracer

This library provides a method for simplifying request tracing and correlation between GoLang services.

What it does

• Extracts the X-Request-ID value or creates a new ID from a UUIDv4
• Adds an entry to the http.Request context
• Injects the X-Request-ID header to outgoing HTTP requests

This allows you to 'follow' requests as they move between various services as they will all have the same ID.

Getting started

Have a look at example.go for a simple example.

go get github.com/djcass44/go-tracer

Using handler functions

http.HandleFunc("/something", tracer.NewFunc(myFunc))

Using handlers

type myHandler struct {}

func (mh myHandler) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
	_, _ = w.Write([]byte("Hello World!"))
}
// later on
http.Handle("/something", tracer.NewHandler(myHandler{}))

Accessing the RequestID

The ID can be pulled from the context directly, or using a helper function

Helper:

requestId := tracer.GetRequestId(request)

Direct:

requestId := request.Context().Value(tracer.ContextKeyID).(string)

Enabling outgoing RequestID injection

This needs to be configured for all instances of http.Client

Note: this will replace the http.Transport of the client

// enable outgoing-tracing for the default http client
tracer.Apply(http.DefaultClient)

var myClient = &http.Client{}
tracer.Apply(myClient)

Contribution

Contributions are more than welcome! Feel free to open a PR, or an issue if you have questions.