added entropy to HTTPRoute-weight (#3880)

Signed-off-by: carsontham <[email protected]>

Author: carsontham

conformance/tests/httproute-weight.go

@@ -91,7 +91,6 @@ func testDistribution(t *testing.T, suite *suite.ConformanceTestSuite, gwAddr st
 		g               errgroup.Group
 		seenMutex       sync.Mutex
 		seen            = make(map[string]float64, 3 /* number of backends */)
-		req             = http.MakeRequest(t, &expected, gwAddr, "HTTP", "http")
 		expectedWeights = map[string]float64{
 			"infra-backend-v1": 0.7,
 			"infra-backend-v2": 0.3,
@@ -101,6 +100,11 @@ func testDistribution(t *testing.T, suite *suite.ConformanceTestSuite, gwAddr st
 	g.SetLimit(concurrentRequests)
 	for i := 0.0; i < totalRequests; i++ {
 		g.Go(func() error {
+			uniqueExpected := expected
+			if err := http.AddEntropy(&uniqueExpected); err != nil {
+				return fmt.Errorf("error adding entropy: %w", err)
+			}
+			req := http.MakeRequest(t, &uniqueExpected, gwAddr, "HTTP", "http")
 			cReq, cRes, err := roundTripper.CaptureRoundTrip(req)
 			if err != nil {
 				return fmt.Errorf("failed to roundtrip request: %w", err)

conformance/tests/mesh/httproute-weight.go

@@ -18,16 +18,13 @@ package meshtests
 
 import (
 	"cmp"
-	"crypto/rand"
 	"errors"
 	"fmt"
 	"math"
-	"math/big"
 	"slices"
 	"strings"
 	"sync"
 	"testing"
-	"time"
 
 	"golang.org/x/sync/errgroup"
 
@@ -93,7 +90,7 @@ func testDistribution(t *testing.T, client echo.MeshPod, expected http.ExpectedR
 	for i := 0.0; i < totalRequests; i++ {
 		g.Go(func() error {
 			uniqueExpected := expected
-			if err := addEntropy(&uniqueExpected); err != nil {
+			if err := http.AddEntropy(&uniqueExpected); err != nil {
 				return fmt.Errorf("error adding entropy: %w", err)
 			}
 			_, cRes, err := client.CaptureRequestResponseAndCompare(t, uniqueExpected)
@@ -148,54 +145,3 @@ func testDistribution(t *testing.T, client echo.MeshPod, expected http.ExpectedR
 	})
 	return errors.Join(errs...)
 }
-
-// addEntropy adds jitter to the request by adding either a delay up to 1 second, or a random header value, or both.
-func addEntropy(exp *http.ExpectedResponse) error {
-	randomNumber := func(limit int64) (*int64, error) {
-		number, err := rand.Int(rand.Reader, big.NewInt(limit))
-		if err != nil {
-			return nil, err
-		}
-		n := number.Int64()
-		return &n, nil
-	}
-
-	// adds a delay
-	delay := func(limit int64) error {
-		randomSleepDuration, err := randomNumber(limit)
-		if err != nil {
-			return err
-		}
-		time.Sleep(time.Duration(*randomSleepDuration) * time.Millisecond)
-		return nil
-	}
-	// adds random header value
-	randomHeader := func(limit int64) error {
-		randomHeaderValue, err := randomNumber(limit)
-		if err != nil {
-			return err
-		}
-		exp.Request.Headers = make(map[string]string)
-		exp.Request.Headers["X-Jitter"] = fmt.Sprintf("%d", *randomHeaderValue)
-		return nil
-	}
-
-	random, err := randomNumber(3)
-	if err != nil {
-		return err
-	}
-
-	switch *random {
-	case 0:
-		return delay(1000)
-	case 1:
-		return randomHeader(10000)
-	case 2:
-		if err := delay(1000); err != nil {
-			return err
-		}
-		return randomHeader(10000)
-	default:
-		return fmt.Errorf("invalid random value: %d", *random)
-	}
-}

conformance/utils/http/http.go

@@ -17,7 +17,9 @@ limitations under the License.
 package http
 
 import (
+	"crypto/rand"
 	"fmt"
+	"math/big"
 	"net"
 	"net/url"
 	"strings"
@@ -478,3 +480,54 @@ func setRedirectRequestDefaults(req *roundtripper.Request, cRes *roundtripper.Ca
 		expected.RedirectRequest.Path = req.URL.Path
 	}
 }
+
+// addEntropy adds jitter to the request by adding either a delay up to 1 second, or a random header value, or both.
+func AddEntropy(exp *ExpectedResponse) error {
+	randomNumber := func(limit int64) (*int64, error) {
+		number, err := rand.Int(rand.Reader, big.NewInt(limit))
+		if err != nil {
+			return nil, err
+		}
+		n := number.Int64()
+		return &n, nil
+	}
+
+	// adds a delay
+	delay := func(limit int64) error {
+		randomSleepDuration, err := randomNumber(limit)
+		if err != nil {
+			return err
+		}
+		time.Sleep(time.Duration(*randomSleepDuration) * time.Millisecond)
+		return nil
+	}
+	// adds random header value
+	randomHeader := func(limit int64) error {
+		randomHeaderValue, err := randomNumber(limit)
+		if err != nil {
+			return err
+		}
+		exp.Request.Headers = make(map[string]string)
+		exp.Request.Headers["X-Jitter"] = fmt.Sprintf("%d", *randomHeaderValue)
+		return nil
+	}
+
+	random, err := randomNumber(3)
+	if err != nil {
+		return err
+	}
+
+	switch *random {
+	case 0:
+		return delay(1000)
+	case 1:
+		return randomHeader(10000)
+	case 2:
+		if err := delay(1000); err != nil {
+			return err
+		}
+		return randomHeader(10000)
+	default:
+		return fmt.Errorf("invalid random value: %d", *random)
+	}
+}