keel/net/http/middleware/telemetry.go
2023-08-11 08:58:46 +02:00

105 lines
2.8 KiB
Go

package middleware
import (
"net/http"
"github.com/foomo/keel/log"
httplog "github.com/foomo/keel/net/http/log"
"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/metric"
"go.opentelemetry.io/otel/propagation"
semconv "go.opentelemetry.io/otel/semconv/v1.10.0"
"go.opentelemetry.io/otel/trace"
"go.uber.org/zap"
)
type (
TelemetryOptions struct {
Name string
OtelOpts []otelhttp.Option
InjectPropagationHeader bool
}
TelemetryOption func(*TelemetryOptions)
)
// GetDefaultTelemetryOptions returns the default options
func GetDefaultTelemetryOptions() TelemetryOptions {
return TelemetryOptions{
OtelOpts: []otelhttp.Option{},
InjectPropagationHeader: true,
}
}
// Telemetry middleware
func Telemetry(opts ...TelemetryOption) Middleware {
options := GetDefaultTelemetryOptions()
for _, opt := range opts {
if opt != nil {
opt(&options)
}
}
return TelemetryWithOptions(options)
}
func TelemetryWithName(v string) TelemetryOption {
return func(o *TelemetryOptions) {
o.Name = v
}
}
func TelemetryWithInjectPropagationHeader(v bool) TelemetryOption {
return func(o *TelemetryOptions) {
o.InjectPropagationHeader = v
}
}
// TelemetryWithOtelOpts middleware options
func TelemetryWithOtelOpts(v ...otelhttp.Option) TelemetryOption {
return func(o *TelemetryOptions) {
o.OtelOpts = v
}
}
// TelemetryWithOptions middleware
func TelemetryWithOptions(opts TelemetryOptions) Middleware {
return func(l *zap.Logger, name string, next http.Handler) http.Handler {
if opts.Name != "" {
name = opts.Name
}
// TODO remove once https://github.com/open-telemetry/opentelemetry-go-contrib/pull/771 is merged
m := otel.Meter(
"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp",
metric.WithInstrumentationVersion(otelhttp.Version()),
)
c, err := m.Int64Counter(
"foo_"+otelhttp.RequestCount,
metric.WithDescription("counts number of requests withs specific status code"),
)
if err != nil {
otel.Handle(err)
}
return otelhttp.NewHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if opts.InjectPropagationHeader {
otel.GetTextMapPropagator().Inject(r.Context(), propagation.HeaderCarrier(w.Header()))
}
if labeler, ok := httplog.LabelerFromRequest(r); ok {
if spanCtx := trace.SpanContextFromContext(r.Context()); spanCtx.IsValid() {
labeler.Add(log.FTraceID(spanCtx.TraceID().String()))
}
}
// wrap response write to get access to status & size
wr := WrapResponseWriter(w)
next.ServeHTTP(wr, r)
if labeler, ok := otelhttp.LabelerFromContext(r.Context()); ok {
c.Add(r.Context(), 1, metric.WithAttributes(append(labeler.Get(), semconv.HTTPStatusCodeKey.Int(wr.StatusCode()))...))
}
}), name, opts.OtelOpts...)
}
}