feat(loadbalance): enhance consistent hashing with useSourceIp support (#2844)

pkg/ingress/kube/annotations/loadbalance.go

@@ -50,13 +50,13 @@ var (
 	headersMapping = map[string]string{
 		"$request_uri": ":path",
 		"$host":        ":authority",
-		"$remote_addr": "x-envoy-external-address",
 	}
 )
 
 type consistentHashByOther struct {
 	header      string
 	queryParam  string
+	useSourceIp bool
 }
 
 type consistentHashByCookie struct {
@@ -110,6 +110,12 @@ func (l loadBalance) Parse(annotations Annotations, config *Ingress, _ *GlobalCo
 	} else if isOtherAffinity(annotations) {
 		if key, err := annotations.ParseStringASAP(upstreamHashBy); err == nil &&
 			strings.HasPrefix(key, varIndicator) {
+			// Special case for $remote_addr: use useSourceIp instead of header mapping
+			if key == "$remote_addr" {
+				loadBalanceConfig.other = &consistentHashByOther{
+					useSourceIp: true,
+				}
+			} else {
 				value, exist := headersMapping[key]
 				if exist {
 					loadBalanceConfig.other = &consistentHashByOther{
@@ -127,6 +133,7 @@ func (l loadBalance) Parse(annotations Annotations, config *Ingress, _ *GlobalCo
 					}
 				}
 			}
+		}
 	} else {
 		if lb, err := annotations.ParseStringASAP(loadBalanceAnnotation); err == nil {
 			lb = strings.ToUpper(lb)
@@ -165,7 +172,13 @@ func (l loadBalance) ApplyTrafficPolicy(trafficPolicy *networking.TrafficPolicy,
 		}
 	} else if loadBalanceConfig.other != nil {
 		var consistentHash *networking.LoadBalancerSettings_ConsistentHashLB
-		if loadBalanceConfig.other.header != "" {
+		if loadBalanceConfig.other.useSourceIp {
+			consistentHash = &networking.LoadBalancerSettings_ConsistentHashLB{
+				HashKey: &networking.LoadBalancerSettings_ConsistentHashLB_UseSourceIp{
+					UseSourceIp: true,
+				},
+			}
+		} else if loadBalanceConfig.other.header != "" {
 			consistentHash = &networking.LoadBalancerSettings_ConsistentHashLB{
 				HashKey: &networking.LoadBalancerSettings_ConsistentHashLB_HttpHeaderName{
 					HttpHeaderName: loadBalanceConfig.other.header,

pkg/ingress/kube/annotations/loadbalance_test.go

@@ -109,7 +109,7 @@ func TestLoadBalanceParse(t *testing.T) {
 			expect: &LoadBalanceConfig{
 				simple: networking.LoadBalancerSettings_ROUND_ROBIN,
 				other: &consistentHashByOther{
-					header: "x-envoy-external-address",
+					useSourceIp: true,
 				},
 			},
 		},
@@ -233,6 +233,27 @@ func TestLoadBalanceApplyTrafficPolicy(t *testing.T) {
 				},
 			},
 		},
+		{
+			config: &Ingress{
+				LoadBalance: &LoadBalanceConfig{
+					other: &consistentHashByOther{
+						useSourceIp: true,
+					},
+				},
+			},
+			input: &networking.TrafficPolicy_PortTrafficPolicy{},
+			expect: &networking.TrafficPolicy_PortTrafficPolicy{
+				LoadBalancer: &networking.LoadBalancerSettings{
+					LbPolicy: &networking.LoadBalancerSettings_ConsistentHash{
+						ConsistentHash: &networking.LoadBalancerSettings_ConsistentHashLB{
+							HashKey: &networking.LoadBalancerSettings_ConsistentHashLB_UseSourceIp{
+								UseSourceIp: true,
+							},
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for _, inputCase := range inputCases {

samples/loadbalance/useSourceIp-example.yaml

@@ -0,0 +1,155 @@
+# Example: Load Balancing with useSourceIp Support
+# This example demonstrates the enhanced consistent hashing feature
+# that uses source IP for load balancing instead of headers.
+#
+# Issue: https://github.com/alibaba/higress/issues/2790
+# PR: https://github.com/alibaba/higress/pull/2844
+#
+# The key improvement is that $remote_addr now uses useSourceIp field
+# instead of x-envoy-external-address header, which works better for
+# private IP addresses.
+
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: test-remote-addr
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echo-server-1
+  namespace: test-remote-addr
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: echo-server-1
+  template:
+    metadata:
+      labels:
+        app: echo-server-1
+    spec:
+      containers:
+        - name: echo-server
+          image: hashicorp/http-echo:0.2.3
+          args:
+            - "-text=Server 1 - IP: $(hostname -i)"
+          ports:
+            - containerPort: 5678
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echo-server-2
+  namespace: test-remote-addr
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: echo-server-2
+  template:
+    metadata:
+      labels:
+        app: echo-server-2
+    spec:
+      containers:
+        - name: echo-server
+          image: hashicorp/http-echo:0.2.3
+          args:
+            - "-text=Server 2 - IP: $(hostname -i)"
+          ports:
+            - containerPort: 5678
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: echo-service
+  namespace: test-remote-addr
+spec:
+  selector:
+    app: echo-server-1
+  ports:
+    - port: 80
+      targetPort: 5678
+      name: http
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: echo-service-2
+  namespace: test-remote-addr
+spec:
+  selector:
+    app: echo-server-2
+  ports:
+    - port: 80
+      targetPort: 5678
+      name: http
+---
+# Example 1: Using $remote_addr with useSourceIp (NEW FEATURE)
+# This configuration now uses source IP directly for consistent hashing
+# instead of relying on x-envoy-external-address header
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: test-remote-addr-source-ip
+  namespace: test-remote-addr
+  annotations:
+    higress.io/upstream-hash-by: "$remote_addr"
+spec:
+  ingressClassName: higress
+  rules:
+    - host: test-source-ip.local
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: echo-service
+                port:
+                  number: 80
+---
+# Example 2: Using traditional header-based hashing for comparison
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: test-remote-addr-header
+  namespace: test-remote-addr
+  annotations:
+    higress.io/upstream-hash-by: "$http_x_real_ip"
+spec:
+  ingressClassName: higress
+  rules:
+    - host: test-header.local
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: echo-service-2
+                port:
+                  number: 80
+---
+# Test client for sending requests
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: test-client
+  namespace: test-remote-addr
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: test-client
+  template:
+    metadata:
+      labels:
+        app: test-client
+    spec:
+      containers:
+        - name: curl
+          image: busybox:1.28
+          command: ["sleep", "3600"]