1、初始化项目

common/middleware/trace.go

@@ -0,0 +1,27 @@
+package middleware
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/opentracing/opentracing-go"
+)
+
+// Trace 链路追踪
+func Trace() gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		var sp opentracing.Span
+		opName := ctx.Request.URL.Path
+		// Attempt to join a trace by getting trace context from the headers.
+		wireContext, err := opentracing.GlobalTracer().Extract(
+			opentracing.TextMap,
+			opentracing.HTTPHeadersCarrier(ctx.Request.Header))
+		if err != nil {
+			// If for whatever reason we can't join, go ahead and start a new root span.
+			sp = opentracing.StartSpan(opName)
+		} else {
+			sp = opentracing.StartSpan(opName, opentracing.ChildOf(wireContext))
+		}
+		ctx.Set("traceSpan", sp)
+		ctx.Next()
+		sp.Finish()
+	}
+}