接入 ARMS 应用监控以后,ARMS 探针将会对常见的 Go 组件进行了自动埋点,因此不需要修改任何代码,就可以实现调用链信息的采集。针对github.com/gorilla/websocket
的应用,ARMS 默认不提供埋点,如果您需要在调用链信息中体现业务方法的执行情况,可以引入OpenTelemetry Go SDK,在业务代码中增加自定义埋点。
前提条件
步骤一:Client 端埋点
将创建 Span 的信息放到 body 中透传到服务端。
package main
import (
"context"
"encoding/json"
"flag"
"fmt"
"github.com/gorilla/websocket"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/propagation"
"go.opentelemetry.io/otel/sdk/trace"
tracex "go.opentelemetry.io/otel/trace"
"log"
"net/url"
"os"
"os/signal"
"time"
)
func init() {
tp := trace.NewTracerProvider(trace.WithSampler(trace.AlwaysSample()))
otel.SetTracerProvider(tp)
prop := propagation.TraceContext{}
otel.SetTextMapPropagator(prop)
}
var addr = flag.String("addr", "localhost:8080", "http service address")
func main() {
flag.Parse()
log.SetFlags(0)
interrupt := make(chan os.Signal, 1)
signal.Notify(interrupt, os.Interrupt)
u := url.URL{Scheme: "ws", Host: *addr, Path: "/echo"}
log.Printf("connecting to %s", u.String())
c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
if err != nil {
log.Fatal("dial:", err)
}
defer c.Close()
done := make(chan struct{})
go func() {
defer close(done)
for {
_, message, err := c.ReadMessage()
if err != nil {
log.Println("read:", err)
return
}
log.Printf("recv: %s", message)
}
}()
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case <-done:
return
case t := <-ticker.C:
tracer := otel.GetTracerProvider().Tracer("")
opts := append([]tracex.SpanStartOption{}, tracex.WithSpanKind(tracex.SpanKindClient))
//将创建的span的trace信息写入body中传到服务端,这里只是demo,可以根据代码情况自行调整
ctx, span := tracer.Start(context.Background(), "Client/User defined span", opts...)
defer span.End()
var headerMap propagation.MapCarrier
headerMap = make(map[string]string)
otel.GetTextMapPropagator().Inject(ctx, headerMap)
xx, _ := json.Marshal(headerMap)
y := t.String() + "|" + string(xx)
err := c.WriteMessage(websocket.TextMessage, []byte(y))
if err != nil {
log.Println("write:", err)
return
}
span.SetAttributes(attribute.String("client", "client-with-ot"))
span.SetAttributes(attribute.Bool("user.defined", true))
case <-interrupt:
log.Println("interrupt")
// Cleanly close the connection by sending a close message and then
// waiting (with timeout) for the server to close the connection.
err := c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
if err != nil {
log.Println("write close:", err)
return
}
select {
case <-done:
case <-time.After(time.Second):
}
return
}
}
}
步骤二:服务端埋点
解析从客户端接收到 Trace 信息,还原后创建服务端 Span。
package main
import (
"context"
"encoding/json"
"flag"
"fmt"
"github.com/gorilla/websocket"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/propagation"
tracex "go.opentelemetry.io/otel/sdk/trace"
"go.opentelemetry.io/otel/trace"
"html/template"
"log"
"net/http"
"strings"
)
var addr = flag.String("addr", "localhost:8080", "http service address")
var upgrader = websocket.Upgrader{} // use default options
func init() {
tp := tracex.NewTracerProvider()
otel.SetTracerProvider(tp)
prop := propagation.TraceContext{}
otel.SetTextMapPropagator(prop)
}
func echo(w http.ResponseWriter, r *http.Request) {
c, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Print("upgrade:", err)
return
}
defer c.Close()
for {
mt, message, err := c.ReadMessage()
if err != nil {
log.Println("read:", err)
break
}
log.Printf("recv: %s", message)
var headerMap propagation.MapCarrier
headerMap = make(map[string]string)
ctxRequest := context.Background()
xx := strings.Split(string(message), "|")
//header := make(map[string]string)
err = json.Unmarshal([]byte(xx[1]), &headerMap)
if err != nil {
fmt.Println(err.Error())
}
xxCtx := otel.GetTextMapPropagator().Extract(ctxRequest, headerMap)
tracer := otel.GetTracerProvider().Tracer("")
opts := append([]trace.SpanStartOption{}, trace.WithSpanKind(trace.SpanKindServer))
_, span := tracer.Start(xxCtx, "Server/User defined span", opts...)
err = c.WriteMessage(mt, message)
if err != nil {
log.Println("write:", err)
break
}
fmt.Println(span.SpanContext().TraceID())
span.End()
}
}
func home(w http.ResponseWriter, r *http.Request) {
homeTemplate.Execute(w, "ws://"+r.Host+"/echo")
}
func main() {
flag.Parse()
log.SetFlags(0)
http.HandleFunc("/echo", echo)
http.HandleFunc("/", home)
log.Fatal(http.ListenAndServe(*addr, nil))
}
var homeTemplate = template.Must(template.New("").Parse(`
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
window.addEventListener("load", function(evt) {
var output = document.getElementById("output");
var input = document.getElementById("input");
var ws;
var print = function(message) {
var d = document.createElement("div");
d.textContent = message;
output.appendChild(d);
output.scroll(0, output.scrollHeight);
};
document.getElementById("open").onclick = function(evt) {
if (ws) {
return false;
}
ws = new WebSocket("{{.}}");
ws.onopen = function(evt) {
print("OPEN");
}
ws.onclose = function(evt) {
print("CLOSE");
ws = null;
}
ws.onmessage = function(evt) {
print("RESPONSE: " + evt.data);
}
ws.onerror = function(evt) {
print("ERROR: " + evt.data);
}
return false;
};
document.getElementById("send").onclick = function(evt) {
if (!ws) {
return false;
}
print("SEND: " + input.value);
ws.send(input.value);
return false;
};
document.getElementById("close").onclick = function(evt) {
if (!ws) {
return false;
}
ws.close();
return false;
};
});
</script>
</head>
<body>
<table>
<tr><td valign="top" width="50%">
<p>Click "Open" to create a connection to the server,
"Send" to send a message to the server and "Close" to close the connection.
You can change the message and send multiple times.
<p>
<form>
<button id="open">Open</button>
<button id="close">Close</button>
<p><input id="input" type="text" value="Hello world!">
<button id="send">Send</button>
</form>
</td><td valign="top" width="50%">
<div id="output" style="max-height: 70vh;overflow-y: scroll;"></div>
</td></tr></table>
</body>
</html>
`))
步骤三:查询调用链
在ARMS控制台的 页面单击应用名称,然后单击调用链分析页签,查看自定义埋点的调用链详情。更多信息,请参见调用链分析。
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