grafana/pkg/infra/httpclient/httpclientprovider/tracing_middleware.go
2023-10-03 14:54:20 +02:00

67 lines
2.2 KiB
Go

package httpclientprovider
import (
"fmt"
"net/http"
"net/http/httptrace"
"strconv"
"github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
"go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/codes"
semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
"go.opentelemetry.io/otel/trace"
"github.com/grafana/grafana/pkg/infra/log"
"github.com/grafana/grafana/pkg/infra/tracing"
)
const (
TracingMiddlewareName = "tracing"
httpContentLengthTagKey = "http.content_length"
)
func TracingMiddleware(logger log.Logger, tracer tracing.Tracer) httpclient.Middleware {
return httpclient.NamedMiddlewareFunc(TracingMiddlewareName, func(opts httpclient.Options, next http.RoundTripper) http.RoundTripper {
return httpclient.RoundTripperFunc(func(req *http.Request) (*http.Response, error) {
ctx, span := tracer.Start(req.Context(), "HTTP Outgoing Request", trace.WithSpanKind(trace.SpanKindClient))
defer span.End()
ctx = httptrace.WithClientTrace(ctx, otelhttptrace.NewClientTrace(ctx, otelhttptrace.WithoutSubSpans(), otelhttptrace.WithoutHeaders()))
req = req.WithContext(ctx)
for k, v := range opts.Labels {
span.SetAttributes(attribute.String(k, v))
}
tracer.Inject(ctx, req.Header, span)
res, err := next.RoundTrip(req)
span.SetAttributes(semconv.HTTPURL(req.URL.String()))
span.SetAttributes(semconv.HTTPMethod(req.Method))
// ext.SpanKind.Set(span, ext.SpanKindRPCClientEnum)
if err != nil {
span.SetStatus(codes.Error, "request failed")
span.RecordError(err)
return res, err
}
if res != nil {
// we avoid measuring contentlength less than zero because it indicates
// that the content size is unknown. https://godoc.org/github.com/badu/http#Response
if res.ContentLength > 0 {
span.SetAttributes(attribute.Int64(httpContentLengthTagKey, res.ContentLength))
}
span.SetAttributes(semconv.HTTPStatusCode(res.StatusCode))
if res.StatusCode >= 400 {
span.SetStatus(codes.Error, fmt.Sprintf("error with HTTP status code %s", strconv.Itoa(res.StatusCode)))
}
}
return res, err
})
})
}