Merge pull request #4321 from shuqz/shuqz-grpcroute

[feat gw-api]support multiple header value in condition

Author: shuqz

pkg/gateway/routeutils/route_rule_condition.go

@@ -2,10 +2,11 @@ package routeutils
 
 import (
 	"fmt"
+	"strings"
+
 	"github.com/pkg/errors"
 	elbv2model "sigs.k8s.io/aws-load-balancer-controller/pkg/model/elbv2"
 	gwv1 "sigs.k8s.io/gateway-api/apis/v1"
-	"strings"
 )
 
 // BuildHttpRuleConditions each match will be mapped to a ruleCondition, conditions within same match will be ANDed
@@ -98,8 +99,7 @@ func buildHttpHeaderCondition(headers []gwv1.HTTPHeaderMatch) []elbv2model.RuleC
 				Field: elbv2model.RuleConditionFieldHTTPHeader,
 				HTTPHeaderConfig: &elbv2model.HTTPHeaderConditionConfig{
 					HTTPHeaderName: string(header.Name),
-					// for a given HTTPHeaderName, ALB rule can accept a list of values. However, gateway route headers only accept one value per name, and name cannot duplicate.
-					Values: []string{header.Value},
+					Values:         generateValuesFromMatchHeaderValue(header.Value),
 				},
 			},
 		}
@@ -200,8 +200,7 @@ func buildGrpcHeaderCondition(headers []gwv1.GRPCHeaderMatch) []elbv2model.RuleC
 				Field: elbv2model.RuleConditionFieldHTTPHeader,
 				HTTPHeaderConfig: &elbv2model.HTTPHeaderConditionConfig{
 					HTTPHeaderName: string(header.Name),
-					// for a given HTTPHeaderName, ALB rule can accept a list of values. However, gateway route headers only accept one value per name, and name cannot duplicate.
-					Values: []string{header.Value},
+					Values:         generateValuesFromMatchHeaderValue(header.Value),
 				},
 			},
 		}
@@ -234,3 +233,29 @@ func buildGrpcMethodCondition(method *gwv1.GRPCMethodMatch) ([]elbv2model.RuleCo
 		},
 	}, nil
 }
+
+// generateValuesFromMatchHeaderValue takes in header value from route match
+// returns list of values
+// for a given HTTPHeaderName/GRPCHeaderName, ALB rule can accept a list of values. However, gateway route headers only accept one value per name, and name cannot duplicate.
+func generateValuesFromMatchHeaderValue(headerValue string) []string {
+	var values []string
+	var current strings.Builder
+
+	for i := 0; i < len(headerValue); i++ {
+		if headerValue[i] == '\\' && i+1 < len(headerValue) {
+			// Escape sequence - add the escaped character literally
+			current.WriteByte(headerValue[i+1])
+			i++ // skip the escaped character
+		} else if headerValue[i] == ',' {
+			// Unescaped comma - split here
+			values = append(values, current.String())
+			current.Reset()
+		} else {
+			// Regular character
+			current.WriteByte(headerValue[i])
+		}
+	}
+
+	values = append(values, current.String())
+	return values
+}

pkg/gateway/routeutils/route_rule_condition_test.go

@@ -1,6 +1,7 @@
 package routeutils
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -696,3 +697,71 @@ func Test_buildGrpcMethodCondition(t *testing.T) {
 		})
 	}
 }
+
+func TestGenerateValuesFromMatchHeaderValue(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected []string
+	}{
+		{
+			name:     "simple comma separation",
+			input:    "a,b,c",
+			expected: []string{"a", "b", "c"},
+		},
+		{
+			name:     "escaped comma",
+			input:    "a\\,b,c",
+			expected: []string{"a,b", "c"},
+		},
+		{
+			name:     "escaped backslash",
+			input:    "a\\\\,b",
+			expected: []string{"a\\", "b"},
+		},
+		{
+			name:     "multiple escaped commas",
+			input:    "a\\,b\\,c",
+			expected: []string{"a,b,c"},
+		},
+		{
+			name:     "mixed escapes",
+			input:    "a\\\\,b\\,c,d",
+			expected: []string{"a\\", "b,c", "d"},
+		},
+		{
+			name:     "no commas",
+			input:    "single-value",
+			expected: []string{"single-value"},
+		},
+		{
+			name:     "empty string",
+			input:    "",
+			expected: []string{""},
+		},
+		{
+			name:     "only commas",
+			input:    ",,",
+			expected: []string{"", "", ""},
+		},
+		{
+			name:     "escaped other characters",
+			input:    "a\\n,b\\t",
+			expected: []string{"an", "bt"},
+		},
+		{
+			name:     "backslash at end",
+			input:    "a\\",
+			expected: []string{"a\\"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := generateValuesFromMatchHeaderValue(tt.input)
+			if !reflect.DeepEqual(result, tt.expected) {
+				t.Errorf("got %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}