traefik/pkg/middlewares/observability/entrypoint.go
2024-03-12 09:48:04 +01:00

98 lines
3.4 KiB
Go

package observability
import (
"context"
"fmt"
"net/http"
"strconv"
"strings"
"time"
"github.com/containous/alice"
"github.com/traefik/traefik/v3/pkg/metrics"
"github.com/traefik/traefik/v3/pkg/middlewares"
"github.com/traefik/traefik/v3/pkg/tracing"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/metric"
semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
"go.opentelemetry.io/otel/trace"
"go.opentelemetry.io/otel/trace/noop"
)
const (
entryPointTypeName = "TracingEntryPoint"
)
type entryPointTracing struct {
tracer *tracing.Tracer
entryPoint string
next http.Handler
semConvMetricRegistry *metrics.SemConvMetricsRegistry
}
// WrapEntryPointHandler Wraps tracing to alice.Constructor.
func WrapEntryPointHandler(ctx context.Context, tracer *tracing.Tracer, semConvMetricRegistry *metrics.SemConvMetricsRegistry, entryPointName string) alice.Constructor {
return func(next http.Handler) (http.Handler, error) {
if tracer == nil {
tracer = tracing.NewTracer(noop.Tracer{}, nil, nil)
}
return newEntryPoint(ctx, tracer, semConvMetricRegistry, entryPointName, next), nil
}
}
// newEntryPoint creates a new tracing middleware for incoming requests.
func newEntryPoint(ctx context.Context, tracer *tracing.Tracer, semConvMetricRegistry *metrics.SemConvMetricsRegistry, entryPointName string, next http.Handler) http.Handler {
middlewares.GetLogger(ctx, "tracing", entryPointTypeName).Debug().Msg("Creating middleware")
if tracer == nil {
tracer = tracing.NewTracer(noop.Tracer{}, nil, nil)
}
return &entryPointTracing{
entryPoint: entryPointName,
tracer: tracer,
semConvMetricRegistry: semConvMetricRegistry,
next: next,
}
}
func (e *entryPointTracing) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
tracingCtx := tracing.ExtractCarrierIntoContext(req.Context(), req.Header)
start := time.Now()
tracingCtx, span := e.tracer.Start(tracingCtx, "EntryPoint", trace.WithSpanKind(trace.SpanKindServer), trace.WithTimestamp(start))
req = req.WithContext(tracingCtx)
span.SetAttributes(attribute.String("entry_point", e.entryPoint))
e.tracer.CaptureServerRequest(span, req)
recorder := newStatusCodeRecorder(rw, http.StatusOK)
e.next.ServeHTTP(recorder, req)
e.tracer.CaptureResponse(span, recorder.Header(), recorder.Status(), trace.SpanKindServer)
end := time.Now()
span.End(trace.WithTimestamp(end))
if e.semConvMetricRegistry != nil && e.semConvMetricRegistry.HTTPServerRequestDuration() != nil {
var attrs []attribute.KeyValue
if recorder.Status() < 100 || recorder.Status() >= 600 {
attrs = append(attrs, attribute.Key("error.type").String(fmt.Sprintf("Invalid HTTP status code ; %d", recorder.Status())))
} else if recorder.Status() >= 400 {
attrs = append(attrs, attribute.Key("error.type").String(strconv.Itoa(recorder.Status())))
}
attrs = append(attrs, semconv.HTTPRequestMethodKey.String(req.Method))
attrs = append(attrs, semconv.HTTPResponseStatusCode(recorder.Status()))
attrs = append(attrs, semconv.NetworkProtocolName(strings.ToLower(req.Proto)))
attrs = append(attrs, semconv.NetworkProtocolVersion(Proto(req.Proto)))
attrs = append(attrs, semconv.ServerAddress(req.Host))
attrs = append(attrs, semconv.URLScheme(req.Header.Get("X-Forwarded-Proto")))
e.semConvMetricRegistry.HTTPServerRequestDuration().Record(req.Context(), end.Sub(start).Seconds(), metric.WithAttributes(attrs...))
}
}