Lambda middleware (#9)

* lambda middleware wip

* major rework, with lambda support

* fix lint

.gitignore

@@ -31,3 +31,5 @@ build
 *.coverprofile
 
 *.env
+
+*.prof

Makefile

@@ -5,7 +5,7 @@ HTTP_PROXY = ${http_proxy}
 HTTPS_PROXY = ${https_proxy}
 
 # Many Go tools take file globs or directories as arguments instead of packages.
-PKG_FILES ?= *.go http ext log demo
+PKG_FILES ?= *.go core ext log demo
 
 # The linting tools evolve with each Go version, so run them only on the latest
 # stable release.

README.md

@@ -22,19 +22,29 @@ $ glide get github.com/Nordstrom/ctrace-go
 ## Usage
 Add instrumentation to the operations you want to track.  Most of this is done by middleware.
 
-### Singleton Initialization
-First initialize the Global Tracer Singleton as early as possible.
+### Initialization
+First import ctrace.
 
 ```go
 import (
 	ctrace "github.com/Nordstrom/ctrace-go"
-	opentracing "github.com/opentracing/opentracing-go"
 )
+```
 
-func main() {
-	opentracing.InitGlobalTracer(ctrace.New())
+This initializes the global Tracer with default settings so you can call
+```go
+tracer := ctrace.Global()
+```
 
-	// ...
+If you need to initialize the global tracer with customizations you will need to
+call the following early in the code.  For example you can call it in main as follows.
+
+```go
+func main() {
+	ctrace.Init(TracerOptions{
+		MultiEvent: true,
+		Writer:     fileWriter,
+	})
 }
 ```
 
@@ -45,9 +55,7 @@ To automatically instrument incoming HTTP Requests use the TracedHandler.
 import (
 	"net/http"
 
-	ctrace "github.com/Nordstrom/ctrace-go"
 	chttp "github.com/Nordstrom/ctrace-go/http"
-	opentracing "github.com/opentracing/opentracing-go"
 )
 
 func ok(w http.ResponseWriter, r *http.Request) {
@@ -57,7 +65,6 @@ func ok(w http.ResponseWriter, r *http.Request) {
 }
 
 func main() {
-	opentracing.InitGlobalTracer(ctrace.New())
 	http.HandleFunc("/ok", ok)
 	http.ListenAndServe(":8004", chttp.TracedHandler(http.DefaultServeMux))
 }

acceptance_test.go

@@ -14,10 +14,6 @@ import (
 	opentracing "github.com/opentracing/opentracing-go"
 )
 
-func lines(buf bytes.Buffer) []string {
-	return strings.Split(buf.String(), "\n")
-}
-
 var _ = Describe("Acceptance", func() {
 
 	var (
@@ -27,7 +23,7 @@ var _ = Describe("Acceptance", func() {
 
 	BeforeEach(func() {
 		buf.Reset()
-		tracer = ctrace.NewWithOptions(ctrace.TracerOptions{Writer: &buf, MultiEvent: true})
+		tracer = ctrace.Init(ctrace.TracerOptions{Writer: &buf, MultiEvent: true})
 	})
 
 	Describe("Parent and Child with Standard Tags", func() {

bench_test.go

@@ -1,9 +1,10 @@
-package ctrace
+package ctrace_test
 
 import (
 	"os"
 	"testing"
 
+	ctrace "github.com/Nordstrom/ctrace-go"
 	"github.com/Nordstrom/ctrace-go/ext"
 	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/log"
@@ -14,7 +15,7 @@ func BenchmarkParentChildLog(b *testing.B) {
 	if err != nil {
 		return
 	}
-	t := NewWithOptions(TracerOptions{Writer: f})
+	t := ctrace.Init(ctrace.TracerOptions{Writer: f})
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		parent := t.StartSpan("parent",
@@ -48,7 +49,7 @@ func BenchmarkParent(b *testing.B) {
 	if err != nil {
 		return
 	}
-	t := NewWithOptions(TracerOptions{Writer: f})
+	t := ctrace.Init(ctrace.TracerOptions{Writer: f})
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		parent := t.StartSpan("parent",
@@ -70,7 +71,7 @@ func BenchmarkChild(b *testing.B) {
 	if err != nil {
 		return
 	}
-	t := NewWithOptions(TracerOptions{Writer: f})
+	t := ctrace.Init(ctrace.TracerOptions{Writer: f})
 	b.ResetTimer()
 	parent := t.StartSpan("parent",
 		ext.SpanKindServer(),
@@ -104,7 +105,7 @@ func BenchmarkLog(b *testing.B) {
 	if err != nil {
 		return
 	}
-	t := NewWithOptions(TracerOptions{Writer: f})
+	t := ctrace.Init(ctrace.TracerOptions{Writer: f})
 	b.ResetTimer()
 	parent := t.StartSpan("parent",
 		ext.SpanKindServer(),

concurrency_test.go

@@ -1,9 +1,10 @@
-package ctrace
+package ctrace_test
 
 import (
 	"bytes"
 	"sync"
 
+	ctrace "github.com/Nordstrom/ctrace-go"
 	. "github.com/onsi/ginkgo"
 	opentracing "github.com/opentracing/opentracing-go"
 )
@@ -13,7 +14,7 @@ const op = "test"
 var _ = Describe("Concurrency", func() {
 	It("usage", func() {
 		var buf bytes.Buffer
-		trc := NewWithOptions(TracerOptions{
+		trc := ctrace.Init(ctrace.TracerOptions{
 			Writer: &buf,
 			DebugAssertSingleGoroutine: true,
 		})

http/http_suite_test.go → core/core_suite_test.go

@@ -1,4 +1,4 @@
-package http_test
+package core_test
 
 import (
 	. "github.com/onsi/ginkgo"
@@ -7,7 +7,7 @@ import (
 	"testing"
 )
 
-func TestHttp(t *testing.T) {
+func TestCore(t *testing.T) {
 	RegisterFailHandler(Fail)
-	RunSpecs(t, "Http Suite")
+	RunSpecs(t, "Core Suite")
 }

debug.go → core/debug.go

@@ -1,4 +1,4 @@
-package ctrace
+package core
 
 import (
 	"bytes"

json_encoder.go → core/json_encoder.go

@@ -1,4 +1,4 @@
-package ctrace
+package core
 
 import (
 	"fmt"

json_encoder_test.go → core/json_encoder_test.go

@@ -1,4 +1,4 @@
-package ctrace
+package core
 
 import (
 	. "github.com/onsi/ginkgo"

propagation.go → core/propagation.go

@@ -1,4 +1,4 @@
-package ctrace
+package core
 
 import (
 	"net/url"
@@ -8,6 +8,45 @@ import (
 	opentracing "github.com/opentracing/opentracing-go"
 )
 
+const (
+	// HTTPHeaders represents SpanContexts as HTTP header string pairs.
+	//
+	// Unlike TextMap, the HTTPHeaders format requires that the keys and values
+	// be valid as HTTP headers as-is (i.e., character casing may be unstable
+	// and special characters are disallowed in keys, values should be
+	// URL-escaped, etc).
+	//
+	// For Tracer.Inject(): the carrier must be a `TextMapWriter`.
+	//
+	// For Tracer.Extract(): the carrier must be a `TextMapReader`.
+	//
+	// See HTTPHeaderCarrier for an implementation of both TextMapWriter
+	// and TextMapReader that defers to an http.Header instance for storage.
+	// For example, Inject():
+	//
+	//    carrier := ctrace.HTTPHeadersCarrier(httpReq.Header)
+	//    err := span.Tracer().Inject(
+	//        span, ctrace.HTTPHeaders, carrier)
+	//
+	// Or Extract():
+	//
+	//    carrier := ctrace.HTTPHeadersCarrier(httpReq.Header)
+	//    span, err := tracer.Extract(
+	//        ctrace.HTTPHeaders, carrier)
+	//
+	HTTPHeaders = opentracing.HTTPHeaders
+
+	// TextMap represents SpanContexts as key:value string pairs.
+	//
+	// Unlike HTTPHeaders, the TextMap format does not restrict the key or
+	// value character sets in any way.
+	//
+	// For Tracer.Inject(): the carrier must be a `TextMapWriter`.
+	//
+	// For Tracer.Extract(): the carrier must be a `TextMapReader`.
+	TextMap = opentracing.TextMap
+)
+
 // Injector is responsible for injecting SpanContext instances in a manner suitable
 // for propagation via a format-specific "carrier" object. Typically the
 // injection will take place across an RPC boundary, but message queues and

propagation_test.go → core/propagation_test.go

@@ -1,4 +1,4 @@
-package ctrace_test
+package core_test
 
 // func TestSpanPropagator(t *testing.T) {
 // 	const op = "test"