api: cookie based consistent hashing

Relates to envoyproxy#2624

Signed-off-by: Arko Dasgupta <arko@tetrate.io>

api/v1alpha1/loadbalancer_types.go

@@ -56,6 +56,7 @@ const (
 // +union
 //
 // +kubebuilder:validation:XValidation:rule="self.type == 'Header' ? has(self.header) : !has(self.header)",message="If consistent hash type is header, the header field must be set."
+// +kubebuilder:validation:XValidation:rule="self.type == 'Cookie' ? has(self.cookie) : !has(self.cookie)",message="If consistent hash type is cookie, the cookie field must be set."
 type ConsistentHash struct {
 	// ConsistentHashType defines the type of input to hash on. Valid Type values are "SourceIP" or "Header".
 	//
@@ -67,6 +68,12 @@ type ConsistentHash struct {
 	// +optional
 	Header *Header `json:"header,omitempty"`
 
+	// 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.
 	//
 	// +kubebuilder:validation:Minimum=2
@@ -84,14 +91,36 @@ type Header struct {
 	Name string `json:"name"`
 }
 
+// Cookie defines the cookie hashing configuration for consistent hash based
+// load balancing.
+type Cookie struct {
+	// Name of the cookie to hash.
+	// If this cookie doesnt exist in the request, Envoy will generate a cookie and set
+	// the TTL on the response back to the client based on Layer 4
+	// attributes of the backend endpoint, to ensure that these future requests
+	// go to the same backend endpoint. Make sure to set the TTL field for this case.
+	Name string `json:"name"`
+	// TTL of the generated cookie if the cookie is not present. This value sets the
+	// 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"`
+}
+
 // ConsistentHashType defines the type of input to hash on.
 // +kubebuilder:validation:Enum=SourceIP;Header
 type ConsistentHashType string
 
 const (
 	// SourceIPConsistentHashType hashes based on the source IP address.
 	SourceIPConsistentHashType ConsistentHashType = "SourceIP"
-	// HeaderConsistentHashType hashes based on a request header.
+	// HeaderConsistentHas`hType hashes based on a request header.
 	HeaderConsistentHashType ConsistentHashType = "Header"
 )
 

charts/gateway-helm/crds/generated/gateway.envoyproxy.io_backendtrafficpolicies.yaml

@@ -412,6 +412,32 @@ spec:
                       ConsistentHash defines the configuration when the load balancer type is
                       set to ConsistentHash
                     properties:
+                      cookie:
+                        description: Cookie configures the cookie hash policy when
+                          the consistent hash type is set to Cookie.
+                        properties:
+                          attributes:
+                            additionalProperties:
+                              type: string
+                            description: Additional Attributes to set for the generated
+                              cookie.
+                            type: object
+                          name:
+                            description: |-
+                              Name of the cookie to hash.
+                              If this cookie doesnt exist in the request, Envoy will generate a cookie and set
+                              the TTL on the response back to the client based on Layer 4
+                              attributes of the backend endpoint, to ensure that these future requests
+                              go to the same backend endpoint. Make sure to set the TTL field for this case.
+                            type: string
+                          ttl:
+                            description: |-
+                              TTL of the generated cookie if the cookie is not present. This value sets the
+                              Max-Age attribute value.
+                            type: string
+                        required:
+                        - name
+                        type: object
                       header:
                         description: Header configures the header hash policy when
                           the consistent hash type is set to Header.
@@ -444,6 +470,9 @@ spec:
                     - message: If consistent hash type is header, the header field
                         must be set.
                       rule: 'self.type == ''Header'' ? has(self.header) : !has(self.header)'
+                    - message: If consistent hash type is cookie, the cookie field
+                        must be set.
+                      rule: 'self.type == ''Cookie'' ? has(self.cookie) : !has(self.cookie)'
                   slowStart:
                     description: |-
                       SlowStart defines the configuration related to the slow start load balancer policy.

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

@@ -703,7 +703,22 @@ _Appears in:_
 | Value | Description |
 | ----- | ----------- |
 | `SourceIP` | SourceIPConsistentHashType hashes based on the source IP address.<br /> | 
-| `Header` | HeaderConsistentHashType hashes based on a request header.<br /> | 
+| `Header` | HeaderConsistentHas`hType hashes based on a request header.<br /> | 
+
+
+#### Cookie
+
+
+
+Cookie defines the cookie hashing configuration for consistent hash based
+load balancing.
+
+_Appears in:_
+- [ConsistentHash](#consistenthash)
+
+| Field | Type | Required | Description |
+| ---   | ---  | ---      | ---         |
+| `name` | _string_ |  true  | Name of the cookie to hash.<br />If this cookie doesnt 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. |
 
 
 #### CustomHeaderExtensionSettings