micro/util/http/clienttracer.go

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2023-09-08 13:58:11 +03:00
//
// 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/v4/options"
"go.unistack.org/micro/v4/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, options.Labels(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, options.Labels(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",
options.Labels(
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()
}