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danehansdanehans
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Merge pull request #11 from danehans/rr_lb
Adds nginx.ingress.kubernetes.io/load-balance Support
2 parents 7f5cc28 + 54276d4 commit 10fcb51

9 files changed

Lines changed: 458 additions & 1 deletion

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‎pkg/i2gw/implementations/kgateway/emitter.go‎

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Original file line numberDiff line numberDiff line change
@@ -135,6 +135,16 @@ func (e *Emitter) Emit(ir *intermediate.IR) ([]client.Object, error) {
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backendCfg,
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)
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138+
// Apply explicit round_robin load balancing via BackendConfigPolicy.
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// Note: This must come AFTER applySessionAffinityPolicy so ring-hash
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// (session affinity) always takes precedence for a given Service.
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applyLoadBalancingPolicy(
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pol,
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httpRouteKey,
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httpRouteContext,
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backendCfg,
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)
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138148
// Apply enable-access-log via HTTPListenerPolicy.
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applyAccessLogPolicy(
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pol,

‎pkg/i2gw/implementations/kgateway/emitter_integration_test.go‎

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@@ -206,6 +206,15 @@ func TestKgatewayIngressNginxIntegration_Golden(t *testing.T) {
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"pkg", "i2gw", "implementations", "kgateway", "testing", "testdata", "output", "cors.yaml",
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),
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},
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{
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name: "load_balance",
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inputRel: filepath.Join(
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"pkg", "i2gw", "implementations", "kgateway", "testing", "testdata", "input", "load_balance.yaml",
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),
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goldenRel: filepath.Join(
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"pkg", "i2gw", "implementations", "kgateway", "testing", "testdata", "output", "load_balance.yaml",
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),
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},
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}
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211220
for _, tt := range tests {

‎pkg/i2gw/implementations/kgateway/load_balance.go‎

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@@ -0,0 +1,123 @@
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/*
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Copyright 2023 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package kgateway
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import (
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"github.com/kgateway-dev/ingress2gateway/pkg/i2gw/intermediate"
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"github.com/kgateway-dev/kgateway/v2/api/v1alpha1/kgateway"
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"github.com/kgateway-dev/kgateway/v2/api/v1alpha1/shared"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/types"
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gwv1 "sigs.k8s.io/gateway-api/apis/v1"
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)
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// applyLoadBalancingPolicy projects the LoadBalancing IR policy into one or more
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// Kgateway BackendConfigPolicies.
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//
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// Semantics:
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// - We create at most one BackendConfigPolicy per Service.
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// - If SessionAffinity is configured for a Service, it takes precedence and
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// this function will not override the ring-hash configuration.
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// - If there is no SessionAffinity for a Service and LoadBalancing.Strategy is
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// "round_robin", we configure LoadBalancer.RoundRobin on the BackendConfigPolicy.
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// - TargetRefs are populated with all core Service backends that this Policy covers
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// (based on RuleBackendSources).
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func applyLoadBalancingPolicy(
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pol intermediate.Policy,
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httpRouteKey types.NamespacedName,
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httpRouteCtx intermediate.HTTPRouteContext,
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backendCfg map[types.NamespacedName]*kgateway.BackendConfigPolicy,
45+
) bool {
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// Only care about explicit round_robin strategies.
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if pol.LoadBalancing == nil || pol.LoadBalancing.Strategy != intermediate.LoadBalancingStrategyRoundRobin {
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return false
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}
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touched := false
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for _, idx := range pol.RuleBackendSources {
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if idx.Rule >= len(httpRouteCtx.Spec.Rules) {
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continue
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}
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rule := httpRouteCtx.Spec.Rules[idx.Rule]
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if idx.Backend >= len(rule.BackendRefs) {
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continue
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}
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br := rule.BackendRefs[idx.Backend]
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// Only core Service backends.
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if br.BackendRef.Group != nil && *br.BackendRef.Group != "" {
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continue
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}
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if br.BackendRef.Kind != nil && *br.BackendRef.Kind != "Service" {
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continue
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}
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svcName := string(br.BackendRef.Name)
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if svcName == "" {
74+
continue
75+
}
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svcKey := types.NamespacedName{
78+
Namespace: httpRouteKey.Namespace,
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Name: svcName,
80+
}
81+
82+
// Create or reuse BackendConfigPolicy per Service.
83+
bcp, exists := backendCfg[svcKey]
84+
if !exists {
85+
policyName := svcName + "-backend-config"
86+
bcp = &kgateway.BackendConfigPolicy{
87+
ObjectMeta: metav1.ObjectMeta{
88+
Name: policyName,
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Namespace: httpRouteKey.Namespace,
90+
},
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Spec: kgateway.BackendConfigPolicySpec{
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TargetRefs: []shared.LocalPolicyTargetReference{
93+
{
94+
Group: "",
95+
Kind: "Service",
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Name: gwv1.ObjectName(svcName),
97+
},
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},
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},
100+
}
101+
bcp.SetGroupVersionKind(BackendConfigPolicyGVK)
102+
backendCfg[svcKey] = bcp
103+
}
104+
105+
// Respect session affinity precedence:
106+
// If RingHash is already set (via applySessionAffinityPolicy), do not override.
107+
if bcp.Spec.LoadBalancer != nil && bcp.Spec.LoadBalancer.RingHash != nil {
108+
// TODO [danehans] add a notification that we are skipping due to session affinity.
109+
continue
110+
}
111+
112+
if bcp.Spec.LoadBalancer == nil {
113+
bcp.Spec.LoadBalancer = &kgateway.LoadBalancer{}
114+
}
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// Set explicit round_robin.
117+
bcp.Spec.LoadBalancer.RoundRobin = &kgateway.LoadBalancerRoundRobinConfig{}
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touched = true
120+
}
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return touched
123+
}

‎pkg/i2gw/implementations/kgateway/testing/testdata/input/load_balance.yaml‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,64 @@
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apiVersion: networking.k8s.io/v1
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kind: Ingress
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metadata:
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annotations:
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ingress2gateway.kubernetes.io/implementation: kgateway
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nginx.ingress.kubernetes.io/load-balance: "round_robin"
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name: ingress-myservicea1
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namespace: default
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spec:
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ingressClassName: nginx
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rules:
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- host: myservicea.foo.org
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http:
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paths:
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- backend:
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service:
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name: myservicea
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port:
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number: 80
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path: /
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pathType: Prefix
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---
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apiVersion: networking.k8s.io/v1
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kind: Ingress
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metadata:
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annotations:
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ingress2gateway.kubernetes.io/implementation: kgateway
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name: ingress-myservicea2
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namespace: default
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spec:
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ingressClassName: nginx
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rules:
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- host: myservicea.foo.org
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http:
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paths:
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- backend:
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service:
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name: myservicea
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port:
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number: 80
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path: /2
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pathType: Prefix
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---
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apiVersion: networking.k8s.io/v1
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kind: Ingress
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metadata:
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annotations:
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ingress2gateway.kubernetes.io/implementation: kgateway
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nginx.ingress.kubernetes.io/load-balance: "round_robin"
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name: ingress-myserviceb
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namespace: default
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spec:
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ingressClassName: nginx
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rules:
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- host: myserviceb.foo.org
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http:
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paths:
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- backend:
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service:
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name: myserviceb
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port:
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number: 80
63+
path: /
64+
pathType: Prefix

‎pkg/i2gw/implementations/kgateway/testing/testdata/output/load_balance.yaml‎

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@@ -0,0 +1,102 @@
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apiVersion: gateway.networking.k8s.io/v1
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kind: Gateway
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metadata:
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annotations:
5+
gateway.networking.k8s.io/generator: ingress2gateway-dev
6+
name: nginx
7+
namespace: default
8+
spec:
9+
gatewayClassName: kgateway
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listeners:
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- hostname: myservicea.foo.org
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name: myservicea-foo-org-http
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port: 80
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protocol: HTTP
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- hostname: myserviceb.foo.org
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name: myserviceb-foo-org-http
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port: 80
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protocol: HTTP
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status: {}
20+
---
21+
apiVersion: gateway.networking.k8s.io/v1
22+
kind: HTTPRoute
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metadata:
24+
annotations:
25+
gateway.networking.k8s.io/generator: ingress2gateway-dev
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name: ingress-myservicea1-myservicea-foo-org
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namespace: default
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spec:
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hostnames:
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- myservicea.foo.org
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parentRefs:
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- name: nginx
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rules:
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- backendRefs:
35+
- name: myservicea
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port: 80
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matches:
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- path:
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type: PathPrefix
40+
value: /
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- backendRefs:
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- name: myservicea
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port: 80
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matches:
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- path:
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type: PathPrefix
47+
value: /2
48+
status:
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parents: []
50+
---
51+
apiVersion: gateway.networking.k8s.io/v1
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kind: HTTPRoute
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metadata:
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annotations:
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gateway.networking.k8s.io/generator: ingress2gateway-dev
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name: ingress-myserviceb-myserviceb-foo-org
57+
namespace: default
58+
spec:
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hostnames:
60+
- myserviceb.foo.org
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parentRefs:
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- name: nginx
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rules:
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- backendRefs:
65+
- name: myserviceb
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port: 80
67+
matches:
68+
- path:
69+
type: PathPrefix
70+
value: /
71+
status:
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parents: []
73+
---
74+
apiVersion: gateway.kgateway.dev/v1alpha1
75+
kind: BackendConfigPolicy
76+
metadata:
77+
name: myservicea-backend-config
78+
namespace: default
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spec:
80+
targetRefs:
81+
- group: ""
82+
kind: Service
83+
name: myservicea
84+
loadBalancer:
85+
roundRobin: {}
86+
status:
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ancestors: null
88+
---
89+
apiVersion: gateway.kgateway.dev/v1alpha1
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kind: BackendConfigPolicy
91+
metadata:
92+
name: myserviceb-backend-config
93+
namespace: default
94+
spec:
95+
targetRefs:
96+
- group: ""
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kind: Service
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name: myserviceb
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loadBalancer:
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roundRobin: {}
101+
status:
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ancestors: null

‎pkg/i2gw/intermediate/provider_ingressnginx.go‎

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -137,6 +137,10 @@ type Policy struct {
137137
// SessionAffinity defines the session affinity policy.
138138
SessionAffinity *SessionAffinityPolicy
139139

140+
// LoadBalancing controls the upstream load-balancing algorithm. Only round_robin is supported;
141+
// other values are ignored.
142+
LoadBalancing *BackendLoadBalancingPolicy
143+
140144
// RuleBackendSources lists the (rule, backend) pairs within a merged HTTPRoute
141145
// that this policy applies to.
142146
//
@@ -171,6 +175,16 @@ type RateLimitPolicy struct {
171175
BurstMultiplier int32
172176
}
173177

178+
// LoadBalancingStrategy represents the upstream load-balancing mode requested by the Ingress NGINX annotations.
179+
// Currently only round_robin is supported; other values are ignored.
180+
type LoadBalancingStrategy string
181+
182+
const LoadBalancingStrategyRoundRobin LoadBalancingStrategy = "round_robin"
183+
184+
type BackendLoadBalancingPolicy struct {
185+
Strategy LoadBalancingStrategy
186+
}
187+
174188
// AddRuleBackendSources returns a copy of p with idxs added to
175189
// RuleBackendSources, ensuring each (Rule, Backend) pair is unique.
176190
func (p Policy) AddRuleBackendSources(idxs []PolicyIndex) Policy {

‎pkg/i2gw/providers/ingressnginx/converter.go‎

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Original file line numberDiff line numberDiff line change
@@ -48,6 +48,7 @@ func newResourcesToIRConverter() *resourcesToIRConverter {
4848
extAuthFeature,
4949
basicAuthFeature,
5050
sessionAffinityFeature,
51+
loadBalancingFeature,
5152
},
5253
}
5354
}

‎pkg/i2gw/providers/ingressnginx/cors.go‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -28,7 +28,7 @@ import (
2828
)
2929

3030
const (
31-
corsEnabledAnnotation = "nginx.ingress.kubernetes.io/enable-cors"
31+
corsEnabledAnnotation = "nginx.ingress.kubernetes.io/enable-cors"
3232
corsAllowOriginAnnotation = "nginx.ingress.kubernetes.io/cors-allow-origin"
3333
corsAllowCredentialsAnnotation = "nginx.ingress.kubernetes.io/cors-allow-credentials"
3434
corsAllowHeadersAnnotation = "nginx.ingress.kubernetes.io/cors-allow-headers"

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