ipld-eth-server/vendor/gopkg.in/DataDog/dd-trace-go.v1/contrib/gin-gonic/gin/gintrace.go
2018-09-11 16:30:29 -05:00

63 lines
1.9 KiB
Go

// Package gin provides functions to trace the gin-gonic/gin package (https://github.com/gin-gonic/gin).
package gin // import "gopkg.in/DataDog/dd-trace-go.v1/contrib/gin-gonic/gin"
import (
"fmt"
"strconv"
"gopkg.in/DataDog/dd-trace-go.v1/ddtrace"
"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/ext"
"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
"github.com/gin-gonic/gin"
)
// Middleware returns middleware that will trace incoming requests.
// The last parameter is optional and can be used to pass a custom tracer.
func Middleware(service string) gin.HandlerFunc {
return func(c *gin.Context) {
resource := c.HandlerName()
opts := []ddtrace.StartSpanOption{
tracer.ServiceName(service),
tracer.ResourceName(resource),
tracer.SpanType(ext.SpanTypeWeb),
tracer.Tag(ext.HTTPMethod, c.Request.Method),
tracer.Tag(ext.HTTPURL, c.Request.URL.Path),
}
if spanctx, err := tracer.Extract(tracer.HTTPHeadersCarrier(c.Request.Header)); err == nil {
opts = append(opts, tracer.ChildOf(spanctx))
}
span, ctx := tracer.StartSpanFromContext(c.Request.Context(), "http.request", opts...)
defer span.Finish()
// pass the span through the request context
c.Request = c.Request.WithContext(ctx)
// serve the request to the next middleware
c.Next()
span.SetTag(ext.HTTPCode, strconv.Itoa(c.Writer.Status()))
if len(c.Errors) > 0 {
span.SetTag("gin.errors", c.Errors.String())
span.SetTag(ext.Error, c.Errors[0])
}
}
}
// HTML will trace the rendering of the template as a child of the span in the given context.
func HTML(c *gin.Context, code int, name string, obj interface{}) {
span, _ := tracer.StartSpanFromContext(c.Request.Context(), "gin.render.html")
span.SetTag("go.template", name)
defer func() {
if r := recover(); r != nil {
err := fmt.Errorf("error rendering tmpl:%s: %s", name, r)
span.Finish(tracer.WithError(err))
panic(r)
} else {
span.Finish()
}
}()
c.HTML(code, name, obj)
}