tracer: improve

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

util/http/clienttracer.go

@@ -0,0 +1,253 @@
+//
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package http
+
+import (
+	"context"
+	"crypto/tls"
+	"net/http/httptrace"
+	"net/textproto"
+	"strings"
+	"sync"
+
+	"go.unistack.org/micro/v3/tracer"
+)
+
+const (
+	httpStatus     = "http.status"
+	httpHeaderMIME = "http.mime"
+	httpRemoteAddr = "http.remote"
+	httpLocalAddr  = "http.local"
+	httpHost       = "http.host"
+)
+
+var hookMap = map[string]string{
+	"http.dns":     "http.getconn",
+	"http.connect": "http.getconn",
+	"http.tls":     "http.getconn",
+}
+
+func parentHook(hook string) string {
+	if strings.HasPrefix(hook, "http.connect") {
+		return hookMap["http.connect"]
+	}
+	return hookMap[hook]
+}
+
+type clientTracer struct {
+	context.Context
+	tr          tracer.Tracer
+	activeHooks map[string]context.Context
+	root        tracer.Span
+	mtx         sync.Mutex
+}
+
+func NewClientTrace(ctx context.Context, tr tracer.Tracer) *httptrace.ClientTrace {
+	ct := &clientTracer{
+		Context:     ctx,
+		activeHooks: make(map[string]context.Context),
+		tr:          tr,
+	}
+
+	return &httptrace.ClientTrace{
+		GetConn:              ct.getConn,
+		GotConn:              ct.gotConn,
+		PutIdleConn:          ct.putIdleConn,
+		GotFirstResponseByte: ct.gotFirstResponseByte,
+		Got100Continue:       ct.got100Continue,
+		Got1xxResponse:       ct.got1xxResponse,
+		DNSStart:             ct.dnsStart,
+		DNSDone:              ct.dnsDone,
+		ConnectStart:         ct.connectStart,
+		ConnectDone:          ct.connectDone,
+		TLSHandshakeStart:    ct.tlsHandshakeStart,
+		TLSHandshakeDone:     ct.tlsHandshakeDone,
+		WroteHeaderField:     ct.wroteHeaderField,
+		WroteHeaders:         ct.wroteHeaders,
+		Wait100Continue:      ct.wait100Continue,
+		WroteRequest:         ct.wroteRequest,
+	}
+}
+
+func (ct *clientTracer) start(hook, spanName string, attrs ...interface{}) {
+	ct.mtx.Lock()
+	defer ct.mtx.Unlock()
+
+	if hookCtx, found := ct.activeHooks[hook]; !found {
+		var sp tracer.Span
+		ct.activeHooks[hook], sp = ct.tr.Start(ct.getParentContext(hook), spanName, tracer.WithSpanLabels(attrs...), tracer.WithSpanKind(tracer.SpanKindClient))
+		if ct.root == nil {
+			ct.root = sp
+		}
+	} else {
+		// end was called before start finished, add the start attributes and end the span here
+		if span, ok := tracer.SpanFromContext(hookCtx); ok {
+			span.AddLabels(attrs...)
+			span.Finish()
+		}
+
+		delete(ct.activeHooks, hook)
+	}
+}
+
+func (ct *clientTracer) end(hook string, err error, attrs ...interface{}) {
+	ct.mtx.Lock()
+	defer ct.mtx.Unlock()
+	if ctx, ok := ct.activeHooks[hook]; ok { // nolint:nestif
+		if span, ok := tracer.SpanFromContext(ctx); ok {
+			if err != nil {
+				span.SetStatus(tracer.SpanStatusError, err.Error())
+			}
+			span.AddLabels(attrs...)
+			span.Finish()
+		}
+		delete(ct.activeHooks, hook)
+	} else {
+		// start is not finished before end is called.
+		// Start a span here with the ending attributes that will be finished when start finishes.
+		// Yes, it's backwards. v0v
+		ctx, span := ct.tr.Start(ct.getParentContext(hook), hook, tracer.WithSpanLabels(attrs...), tracer.WithSpanKind(tracer.SpanKindClient))
+		if err != nil {
+			span.SetStatus(tracer.SpanStatusError, err.Error())
+		}
+		ct.activeHooks[hook] = ctx
+	}
+}
+
+func (ct *clientTracer) getParentContext(hook string) context.Context {
+	ctx, ok := ct.activeHooks[parentHook(hook)]
+	if !ok {
+		return ct.Context
+	}
+	return ctx
+}
+
+func (ct *clientTracer) span(hook string) (tracer.Span, bool) {
+	ct.mtx.Lock()
+	defer ct.mtx.Unlock()
+	if ctx, ok := ct.activeHooks[hook]; ok {
+		return tracer.SpanFromContext(ctx)
+	}
+	return nil, false
+}
+
+func (ct *clientTracer) getConn(host string) {
+	ct.start("http.getconn", "http.getconn", httpHost, host)
+}
+
+func (ct *clientTracer) gotConn(info httptrace.GotConnInfo) {
+	ct.end("http.getconn",
+		nil,
+		httpRemoteAddr, info.Conn.RemoteAddr().String(),
+		httpLocalAddr, info.Conn.LocalAddr().String(),
+	)
+}
+
+func (ct *clientTracer) putIdleConn(err error) {
+	ct.end("http.receive", err)
+}
+
+func (ct *clientTracer) gotFirstResponseByte() {
+	ct.start("http.receive", "http.receive")
+}
+
+func (ct *clientTracer) dnsStart(info httptrace.DNSStartInfo) {
+	ct.start("http.dns", "http.dns", httpHost, info.Host)
+}
+
+func (ct *clientTracer) dnsDone(info httptrace.DNSDoneInfo) {
+	ct.end("http.dns", info.Err)
+}
+
+func (ct *clientTracer) connectStart(network, addr string) {
+	_ = network
+	ct.start("http.connect."+addr, "http.connect", httpRemoteAddr, addr)
+}
+
+func (ct *clientTracer) connectDone(network, addr string, err error) {
+	_ = network
+	ct.end("http.connect."+addr, err)
+}
+
+func (ct *clientTracer) tlsHandshakeStart() {
+	ct.start("http.tls", "http.tls")
+}
+
+func (ct *clientTracer) tlsHandshakeDone(_ tls.ConnectionState, err error) {
+	ct.end("http.tls", err)
+}
+
+func (ct *clientTracer) wroteHeaderField(k string, v []string) {
+	if sp, ok := ct.span("http.headers"); !ok || sp == nil {
+		ct.start("http.headers", "http.headers")
+	}
+	ct.root.AddLabels("http."+strings.ToLower(k), sliceToString(v))
+}
+
+func (ct *clientTracer) wroteHeaders() {
+	ct.start("http.send", "http.send")
+}
+
+func (ct *clientTracer) wroteRequest(info httptrace.WroteRequestInfo) {
+	if info.Err != nil {
+		ct.root.SetStatus(tracer.SpanStatusError, info.Err.Error())
+	}
+	ct.end("http.send", info.Err)
+}
+
+func (ct *clientTracer) got100Continue() {
+	if sp, ok := ct.span("http.receive"); ok && sp != nil {
+		sp.AddEvent("GOT 100 - Continue")
+	}
+}
+
+func (ct *clientTracer) wait100Continue() {
+	if sp, ok := ct.span("http.receive"); ok && sp != nil {
+		sp.AddEvent("GOT 100 - Wait")
+	}
+}
+
+func (ct *clientTracer) got1xxResponse(code int, header textproto.MIMEHeader) error {
+	if sp, ok := ct.span("http.receive"); ok && sp != nil {
+		sp.AddEvent("GOT 1xx",
+			tracer.WithEventLabels(
+				httpStatus, code,
+				httpHeaderMIME, sm2s(header),
+			),
+		)
+	}
+	return nil
+}
+
+func sliceToString(value []string) string {
+	if len(value) == 0 {
+		return "undefined"
+	}
+	return strings.Join(value, ",")
+}
+
+func sm2s(value map[string][]string) string {
+	var buf strings.Builder
+	for k, v := range value {
+		if buf.Len() != 0 {
+			buf.WriteString(",")
+		}
+		buf.WriteString(k)
+		buf.WriteString("=")
+		buf.WriteString(sliceToString(v))
+	}
+	return buf.String()
+}