ovn lb select the local chassis's backend prefer

[changluyi]

Pull Request

• Make sure you have followed Kube-OVN Code Style.

What type of this PR

Examples of user facing changes:

• Features
• Bug fixes
• Docs
• Tests

ovn 实现原理。

OVN 这部分代码修改原理：

实现原理是获取到vip backend的 chassis ， 新增加流表入下：

is_chassis_resident("nginx-6f55f97f94-8kvlx.default") , 其中 nginx-6f55f97f94-8kvlx.default 是某个vip 的backend下的任意一个lsp，backends=10.16.0.3:80 表示这个lb 在这个chassis下的所有backendip: port 。

  table=13(ls_in_lb           ), priority=140  , match=(ct.new && ip4.dst == 1.1.1.1 && tcp.dst == 80 && is_chassis_resident("nginx-6f55f97f94-8kvlx.default")), action=(ct_lb_mark(backends=10.16.0.3:80; hash_fields="ip_src");)
  table=13(ls_in_lb           ), priority=140  , match=(ct.new && ip4.dst == 1.1.1.1 && tcp.dst == 80 && is_chassis_resident("nginx-6f55f97f94-zlr4p.default")), action=(ct_lb_mark(backends=10.16.0.2:80; hash_fields="ip_src");)

如果hit不到以上流表，就会走原来的ovn lb 规则。

该功能需要配置Load_balancer的 两个字段
option:prefer_local_backend

option:prefer_local_backend=true

ip_port_mappings

"10.16.0.10"="nginx-6f55f97f94-m4bxx.default:10.16.0.4", "10.16.0.2"="nginx-6f55f97f94-zlr4p.default:10.16.0.4", "10.16.0.3"="nginx-6f55f97f94-8kvlx.default:10.16.0.4", "10.16.0.5"="nginx-6f55f97f94-ns9th.default:10.16.0.4"

kube-ovn 增加场景

场景1：switchlbRules 支持 OVN LB 优先走本地 backend

使用方法：

kube-ovn-controller 开启开关 --enable-ovn-lb-prefer-local = true

用例：

kind: SwitchLBRule
metadata:
  name:  cjh-slr-nginx
spec:
  vip: 1.1.1.1
  sessionAffinity: ClientIP
  namespace: default
  selector:
    - app:nginx
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values:
                      - nginx
              topologyKey: "kubernetes.io/hostname"
      containers:
      - name: nginx-container
        image: nginx:alpine
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

场景2: ovn lb 模式下支持 internalTrafficPolicy: Local , 真正实现发送本地 backend

使用方法：

kube-ovn-controller 开启开关 --enable-ovn-lb-prefer-local = true

用例：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-app-container
        image: nginx:alpine
        ports:
        - containerPort: 80

---
apiVersion: v1
kind: Service
metadata:
  name: my-app-service
spec:
  selector:
    app: my-app
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
  internalTrafficPolicy: Local
  type: ClusterIP

场景3：underlay 模式下 和 metallb 一起使用， 该场景主要是为了metallb 模式下支持某个underlay subnet提供外部地址池的vip， vip的后端pod同样在该子网下， 并保证clientIP 不被改变。

流量走向：

使用方法：

1. kube-ovn-controller 开启开关 --enable-ovn-lb-prefer-local = true
2. subnet.spec.enableExternalLBAddress = true
3. subnet.spec.excludeIps 添加外部地址池的地址段。
4. service 配置 externalTrafficPolicy:Local

Which issue(s) this PR fixes

Fixes #(issue-number)

[coveralls]

Pull Request Test Coverage Report for Build 13152489564

Details

• 0 of 445 (0.0%) changed or added relevant lines in 8 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.2%) to 22.129%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/controller/config.go	0	2	0.0%
pkg/controller/init.go	0	5	0.0%
pkg/ovs/ovn-nb-load_balancer.go	0	32	0.0%
pkg/controller/endpoint.go	0	35	0.0%
pkg/controller/service.go	0	40	0.0%
pkg/daemon/controller.go	0	45	0.0%
pkg/ovs/ovs-ofctl.go	0	117	0.0%
pkg/daemon/controller_linux.go	0	169	0.0%

Files with Coverage Reduction	New Missed Lines	%
pkg/controller/init.go	1	0.0%

Totals
Change from base Build 13148817566:	-0.2%
Covered Lines:	10376
Relevant Lines:	46889

---

💛 - Coveralls

[zhangzujian]

The following occasional failure need to be fixed:

  [FAILED] Code Location: /home/zhang/kube-ovn/test/e2e/metallb/e2e_test.go:417
  Expected
      <string>: kube-ovn-control-plane
  to equal
      <string>: kube-ovn-worker
  In [It] at: /home/zhang/kube-ovn/test/e2e/metallb/e2e_test.go:358 @ 02/06/25 02:45:06.75