feat(api): Add support for the header hash policy (#3342)

* Make API changes Signed-off-by: Harry Turton <harryt@canva.com> * Add tests Signed-off-by: Harry Turton <harryt@canva.com> * Fixups Signed-off-by: Harry Turton <harryt@canva.com> * Fixup test compilation issues Signed-off-by: Harry Turton <harryt@canva.com> * Make ConsistentHash a union Signed-off-by: Harry Turton <harryt@canva.com> * Remove redundant TargetRef from tests Signed-off-by: Harry Turton <harryt@canva.com> * Revert test change Signed-off-by: Harry Turton <harryt@canva.com> * Add target ref back Signed-off-by: Harry Turton <harryt@canva.com> * Code review and fix tests Signed-off-by: Harry Turton <harryt@canva.com> * Regen charts Signed-off-by: Harry Turton <harryt@canva.com> * Propagate HeaderName to Header change to the json field Signed-off-by: Harry Turton <harryt@canva.com> * Generate code Signed-off-by: Harry Turton <harryt@canva.com> * Regen manifests Signed-off-by: Harry Turton <harryt@canva.com> * Add +notImplementedHide on Header Signed-off-by: Harry Turton <harryt@canva.com>
envoyproxy · May 8, 2024 · b90f81c · b90f81c
1 parent 4b22373
commit b90f81c
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Showing 5 changed files with 128 additions and 10 deletions.
diff --git a/api/v1alpha1/loadbalancer_types.go b/api/v1alpha1/loadbalancer_types.go
@@ -18,7 +18,7 @@ type LoadBalancer struct {
 	// "ConsistentHash",
 	// "LeastRequest",
 	// "Random",
-	// "RoundRobin",
+	// "RoundRobin".
 	//
 	// +unionDiscriminator
 	Type LoadBalancerType `json:"type"`
@@ -52,18 +52,39 @@ const (
 )
 
 // ConsistentHash defines the configuration related to the consistent hash
-// load balancer policy
+// load balancer policy.
+// +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."
 type ConsistentHash struct {
+	// Valid Type values are  "SourceIP".
+	//
+	// +unionDiscriminator
 	Type ConsistentHashType `json:"type"`
+
+	// Header configures the header hash policy when the consistent hash type is set to Header.
+	//
+	// +optional
+	// +notImplementedHide
+	Header *Header `json:"header,omitempty"`
+}
+
+// Header defines the header hashing configuration for consistent hash based
+// load balancing.
+type Header struct {
+	// Name of the header to hash.
+	Name string `json:"name"`
 }
 
 // ConsistentHashType defines the type of input to hash on.
-// +kubebuilder:validation:Enum=SourceIP
+// +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.
+	HeaderConsistentHashType ConsistentHashType = "Header"
 )
 
 // SlowStart defines the configuration related to the slow start load balancer policy.

diff --git a/api/v1alpha1/zz_generated.deepcopy.go b/api/v1alpha1/zz_generated.deepcopy.go
diff --git a/charts/gateway-helm/crds/generated/gateway.envoyproxy.io_backendtrafficpolicies.yaml b/charts/gateway-helm/crds/generated/gateway.envoyproxy.io_backendtrafficpolicies.yaml
@@ -412,15 +412,29 @@ spec:
                       ConsistentHash defines the configuration when the load balancer type is
                       set to ConsistentHash
                     properties:
+                      header:
+                        description: Header configures the header hash policy when
+                          the consistent hash type is set to Header.
+                        properties:
+                          name:
+                            description: Name of the header to hash.
+                            type: string
+                        required:
+                        - name
+                        type: object
                       type:
-                        description: ConsistentHashType defines the type of input
-                          to hash on.
+                        description: Valid Type values are  "SourceIP".
                         enum:
                         - SourceIP
+                        - Header
                         type: string
                     required:
                     - type
                     type: object
+                    x-kubernetes-validations:
+                    - message: If consistent hash type is header, the header field
+                        must be set.
+                      rule: 'self.type == ''Header'' ? has(self.header) : !has(self.header)'
                   slowStart:
                     description: |-
                       SlowStart defines the configuration related to the slow start load balancer policy.
@@ -444,7 +458,7 @@ spec:
                       "ConsistentHash",
                       "LeastRequest",
                       "Random",
-                      "RoundRobin",
+                      "RoundRobin".
                     enum:
                     - ConsistentHash
                     - LeastRequest

diff --git a/site/content/en/latest/api/extension_types.md b/site/content/en/latest/api/extension_types.md
@@ -555,14 +555,14 @@ _Appears in:_
 
 
 ConsistentHash defines the configuration related to the consistent hash
-load balancer policy
+load balancer policy.
 
 _Appears in:_
 - [LoadBalancer](#loadbalancer)
 
 | Field | Type | Required | Description |
 | ---   | ---  | ---      | ---         |
-| `type` | _[ConsistentHashType](#consistenthashtype)_ |  true  |  |
+| `type` | _[ConsistentHashType](#consistenthashtype)_ |  true  | Valid Type values are  "SourceIP". |
 
 
 #### ConsistentHashType
@@ -577,6 +577,7 @@ _Appears in:_
 | Value | Description |
 | ----- | ----------- |
 | `SourceIP` | SourceIPConsistentHashType hashes based on the source IP address.<br /> | 
+| `Header` | HeaderConsistentHashType hashes based on a request header.<br /> | 
 
 
 #### CustomHeaderExtensionSettings
@@ -1624,6 +1625,21 @@ _Appears in:_
 | `url` | _string_ |  true  | URL is the URL containing the wasm code. |
 
 
+#### Header
+
+
+
+Header defines the header hashing configuration for consistent hash based
+load balancing.
+
+_Appears in:_
+- [ConsistentHash](#consistenthash)
+
+| Field | Type | Required | Description |
+| ---   | ---  | ---      | ---         |
+| `name` | _string_ |  true  | Name of the header to hash. |
+
+
 
 
 #### HeaderMatchType
@@ -2018,7 +2034,7 @@ _Appears in:_
 
 | Field | Type | Required | Description |
 | ---   | ---  | ---      | ---         |
-| `type` | _[LoadBalancerType](#loadbalancertype)_ |  true  | Type decides the type of Load Balancer policy.<br />Valid LoadBalancerType values are<br />"ConsistentHash",<br />"LeastRequest",<br />"Random",<br />"RoundRobin", |
+| `type` | _[LoadBalancerType](#loadbalancertype)_ |  true  | Type decides the type of Load Balancer policy.<br />Valid LoadBalancerType values are<br />"ConsistentHash",<br />"LeastRequest",<br />"Random",<br />"RoundRobin". |
 | `consistentHash` | _[ConsistentHash](#consistenthash)_ |  false  | ConsistentHash defines the configuration when the load balancer type is<br />set to ConsistentHash |
 | `slowStart` | _[SlowStart](#slowstart)_ |  false  | SlowStart defines the configuration related to the slow start load balancer policy.<br />If set, during slow start window, traffic sent to the newly added hosts will gradually increase.<br />Currently this is only supported for RoundRobin and LeastRequest load balancers |
 

diff --git a/test/cel-validation/backendtrafficpolicy_test.go b/test/cel-validation/backendtrafficpolicy_test.go
@@ -194,6 +194,53 @@ func TestBackendTrafficPolicyTarget(t *testing.T) {
 				"spec.loadBalancer: Invalid value: \"object\": If LoadBalancer type is consistentHash, consistentHash field needs to be set",
 			},
 		},
+		{
+			desc: "consistentHash header field not nil when consistentHashType is header",
+			mutate: func(btp *egv1a1.BackendTrafficPolicy) {
+				btp.Spec = egv1a1.BackendTrafficPolicySpec{
+					TargetRef: gwapiv1a2.LocalPolicyTargetReferenceWithSectionName{
+						LocalPolicyTargetReference: gwapiv1a2.LocalPolicyTargetReference{
+							Group: gwapiv1a2.Group("gateway.networking.k8s.io"),
+							Kind:  gwapiv1a2.Kind("Gateway"),
+							Name:  gwapiv1a2.ObjectName("eg"),
+						},
+					},
+					LoadBalancer: &egv1a1.LoadBalancer{
+						Type: egv1a1.ConsistentHashLoadBalancerType,
+						ConsistentHash: &egv1a1.ConsistentHash{
+							Type: "Header",
+							Header: &egv1a1.Header{
+								Name: "name",
+							},
+						},
+					},
+				}
+			},
+			wantErrors: []string{},
+		},
+		{
+			desc: "consistentHash header field nil when consistentHashType is header",
+			mutate: func(btp *egv1a1.BackendTrafficPolicy) {
+				btp.Spec = egv1a1.BackendTrafficPolicySpec{
+					TargetRef: gwapiv1a2.LocalPolicyTargetReferenceWithSectionName{
+						LocalPolicyTargetReference: gwapiv1a2.LocalPolicyTargetReference{
+							Group: gwapiv1a2.Group("gateway.networking.k8s.io"),
+							Kind:  gwapiv1a2.Kind("Gateway"),
+							Name:  gwapiv1a2.ObjectName("eg"),
+						},
+					},
+					LoadBalancer: &egv1a1.LoadBalancer{
+						Type: egv1a1.ConsistentHashLoadBalancerType,
+						ConsistentHash: &egv1a1.ConsistentHash{
+							Type: "Header",
+						},
+					},
+				}
+			},
+			wantErrors: []string{
+				"spec.loadBalancer.consistentHash: Invalid value: \"object\": If consistent hash type is header, the header field must be set",
+			},
+		},
 		{
 			desc: "leastRequest with ConsistentHash nil",
 			mutate: func(btp *egv1a1.BackendTrafficPolicy) {