feat: cookie based consistent hashing

Fixes: #2624

Signed-off-by: Arko Dasgupta <[email protected]>

api/v1alpha1/loadbalancer_types.go

@@ -71,7 +71,6 @@ type ConsistentHash struct {
 	// Cookie configures the cookie hash policy when the consistent hash type is set to Cookie.
 	//
 	// +optional
-	// +notImplementedHide
 	Cookie *Cookie `json:"cookie,omitempty"`
 
 	// The table size for consistent hashing, must be prime number limited to 5000011.
@@ -103,12 +102,10 @@ type Cookie struct {
 	// Max-Age attribute value.
 	//
 	// +optional
-	// +notImplementedHide
 	TTL *metav1.Duration `json:"ttl,omitempty"`
 	// Additional Attributes to set for the generated cookie.
 	//
 	// +optional
-	// +notImplementedHide
 	Attributes map[string]string `json:"attributes,omitempty"`
 }
 

internal/gatewayapi/backendtrafficpolicy.go

@@ -864,6 +864,8 @@ func (t *Translator) buildConsistentHashLoadBalancer(policy *egv1a1.BackendTraff
 		consistentHash.Header = &ir.Header{
 			Name: policy.Spec.LoadBalancer.ConsistentHash.Header.Name,
 		}
+	case egv1a1.CookieConsistentHashType:
+		consistentHash.Cookie = policy.Spec.LoadBalancer.ConsistentHash.Cookie
 	}
 
 	return consistentHash, nil

internal/ir/xds.go

@@ -1770,9 +1770,10 @@ type Random struct{}
 // +k8s:deepcopy-gen=true
 type ConsistentHash struct {
 	// Hash based on the Source IP Address
-	SourceIP  *bool   `json:"sourceIP,omitempty" yaml:"sourceIP,omitempty"`
-	Header    *Header `json:"header,omitempty" yaml:"header,omitempty"`
-	TableSize *uint64 `json:"tableSize,omitempty" yaml:"tableSize,omitempty"`
+	SourceIP  *bool          `json:"sourceIP,omitempty" yaml:"sourceIP,omitempty"`
+	Header    *Header        `json:"header,omitempty" yaml:"header,omitempty"`
+	Cookie    *egv1a1.Cookie `json:"cookie,omitempty" yaml:"cookie,omitempty"`
+	TableSize *uint64        `json:"tableSize,omitempty" yaml:"tableSize,omitempty"`
 }
 
 // Header consistent hash type settings

internal/xds/translator/route.go

@@ -492,6 +492,28 @@ func buildHashPolicy(httpRoute *ir.HTTPRoute) []*routev3.RouteAction_HashPolicy
 			},
 		}
 		return []*routev3.RouteAction_HashPolicy{hashPolicy}
+	case ch.Cookie != nil:
+		hashPolicy := &routev3.RouteAction_HashPolicy{
+			PolicySpecifier: &routev3.RouteAction_HashPolicy_Cookie_{
+				Cookie: &routev3.RouteAction_HashPolicy_Cookie{
+					Name: ch.Cookie.Name,
+				},
+			},
+		}
+		if ch.Cookie.TTL != nil {
+			hashPolicy.GetCookie().Ttl = durationpb.New(ch.Cookie.TTL.Duration)
+		}
+		if ch.Cookie.Attributes != nil {
+			attributes := make([]*routev3.RouteAction_HashPolicy_CookieAttribute, len(ch.Cookie.Attributes))
+			i := 0
+			for name, value := range ch.Cookie.Attributes {
+				attributes[i].Name = name
+				attributes[i].Value = value
+				i++
+			}
+			hashPolicy.GetCookie().Attributes = attributes
+		}
+		return []*routev3.RouteAction_HashPolicy{hashPolicy}
 	case ch.SourceIP != nil:
 		if !*ch.SourceIP {
 			return nil

site/content/en/latest/api/extension_types.md

@@ -755,6 +755,7 @@ _Appears in:_
 | ---   | ---  | ---      | ---         |
 | `type` | _[ConsistentHashType](#consistenthashtype)_ |  true  | ConsistentHashType defines the type of input to hash on. Valid Type values are "SourceIP" or "Header". |
 | `header` | _[Header](#header)_ |  false  | Header configures the header hash policy when the consistent hash type is set to Header. |
+| `cookie` | _[Cookie](#cookie)_ |  false  | Cookie configures the cookie hash policy when the consistent hash type is set to Cookie. |
 | `tableSize` | _integer_ |  false  | The table size for consistent hashing, must be prime number limited to 5000011. |
 
 
@@ -787,6 +788,8 @@ _Appears in:_
 | Field | Type | Required | Description |
 | ---   | ---  | ---      | ---         |
 | `name` | _string_ |  true  | Name of the cookie to hash.<br />If this cookie does not exist in the request, Envoy will generate a cookie and set<br />the TTL on the response back to the client based on Layer 4<br />attributes of the backend endpoint, to ensure that these future requests<br />go to the same backend endpoint. Make sure to set the TTL field for this case. |
+| `ttl` | _[Duration](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.29/#duration-v1-meta)_ |  false  | TTL of the generated cookie if the cookie is not present. This value sets the<br />Max-Age attribute value. |
+| `attributes` | _object (keys:string, values:string)_ |  false  | Additional Attributes to set for the generated cookie. |
 
 
 #### CustomHeaderExtensionSettings

site/content/zh/latest/api/extension_types.md

@@ -755,6 +755,7 @@ _Appears in:_
 | ---   | ---  | ---      | ---         |
 | `type` | _[ConsistentHashType](#consistenthashtype)_ |  true  | ConsistentHashType defines the type of input to hash on. Valid Type values are "SourceIP" or "Header". |
 | `header` | _[Header](#header)_ |  false  | Header configures the header hash policy when the consistent hash type is set to Header. |
+| `cookie` | _[Cookie](#cookie)_ |  false  | Cookie configures the cookie hash policy when the consistent hash type is set to Cookie. |
 | `tableSize` | _integer_ |  false  | The table size for consistent hashing, must be prime number limited to 5000011. |
 
 
@@ -787,6 +788,8 @@ _Appears in:_
 | Field | Type | Required | Description |
 | ---   | ---  | ---      | ---         |
 | `name` | _string_ |  true  | Name of the cookie to hash.<br />If this cookie does not exist in the request, Envoy will generate a cookie and set<br />the TTL on the response back to the client based on Layer 4<br />attributes of the backend endpoint, to ensure that these future requests<br />go to the same backend endpoint. Make sure to set the TTL field for this case. |
+| `ttl` | _[Duration](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.29/#duration-v1-meta)_ |  false  | TTL of the generated cookie if the cookie is not present. This value sets the<br />Max-Age attribute value. |
+| `attributes` | _object (keys:string, values:string)_ |  false  | Additional Attributes to set for the generated cookie. |
 
 
 #### CustomHeaderExtensionSettings