http impl of memory limiter

Author: timannguyen

config/confighttp/confighttp.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/rs/cors"
+	"go.opentelemetry.io/collector/extension/memorylimiter"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel"
 	"golang.org/x/net/http2"
@@ -234,6 +235,10 @@ type HTTPServerSettings struct {
 	// Additional headers attached to each HTTP response sent to the client.
 	// Header values are opaque since they may be sensitive.
 	ResponseHeaders map[string]configopaque.String `mapstructure:"response_headers"`
+
+	// IsLimitMemory is use to enable memory limiter extension if the extension exists. Memory limiter checks
+	// total memory usage restricted by the extension and return an error if memory exceeds.
+	EnableMemoryLimiter bool `mapstructure:"limit_memory"`
 }
 
 // ToListener creates a net.Listener.
@@ -294,6 +299,14 @@ func (hss *HTTPServerSettings) ToServer(host component.Host, settings component.
 		o(serverOpts)
 	}
 
+	if hss.EnableMemoryLimiter {
+		if ext, err := memorylimiter.GetMemoryLimiterExtension(host.GetExtensions()); err != nil {
+			handler = memoryLimiterInterceptor(handler, ext)
+		} else {
+			return nil, err
+		}
+	}
+
 	handler = httpContentDecompressor(handler, serverOpts.errHandler, serverOpts.decoders)
 
 	if hss.MaxRequestBodySize > 0 {
@@ -400,3 +413,13 @@ func maxRequestBodySizeInterceptor(next http.Handler, maxRecvSize int64) http.Ha
 		next.ServeHTTP(w, r)
 	})
 }
+
+func memoryLimiterInterceptor(next http.Handler, ml memorylimiter.MemoryLimiter) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := ml.CheckMemory(); err != nil {
+			http.Error(w, http.StatusText(http.StatusTooManyRequests), http.StatusTooManyRequests)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}