Container Service for Kubernetes:Configure Classic Load Balancer (CLB) Using Annotations

Create an Internet-facing CLB instance

By default, ACK creates an Internet-facing CLB instance when you create a Service of type LoadBalancer.

apiVersion: v1
kind: Service
metadata:
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Create an internal CLB instance

Annotation: alibaba-cloud-loadbalancer-address-type

For internal CLB instances, specify a vSwitch explicitly using alibaba-cloud-loadbalancer-vswitch-id. If you don't, CCM selects a vSwitch automatically based on its version:

• CCM earlier than v2.13.0: uses the first vSwitch configured for the cluster control plane

• CCM v2.13.0 or later: automatically selects an available vSwitch

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-address-type: "intranet"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vswitch-id: "${YOUR_VSWITCH_ID}"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Specify the CLB instance type

Annotations: Multiple annotations required.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-instance-charge-type: "PayBySpec"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-spec: "slb.s1.small"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Create a pay-by-bandwidth CLB instance

Annotations: Both annotations are required.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-charge-type: "paybybandwidth"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-bandwidth: "2"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Use an existing CLB instance

Annotation: alibaba-cloud-loadbalancer-id

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: "<your-clb-instance-id>"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Use an existing CLB instance and force override listeners

Annotations: Both annotations are required. Force override deletes existing listeners when port conflicts occur.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: "<your-clb-instance-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-force-override-listeners: "true"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Specify primary and secondary zones

Annotations: Both annotations are required. Zones cannot be changed after creation. Not all regions support primary and secondary zones — check the CLB console.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-master-zoneid: "cn-hangzhou-k"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-slave-zoneid: "cn-hangzhou-j"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Specify a vSwitch for an internal CLB instance

Annotations: Both annotations are required.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-address-type: "intranet"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vswitch-id: "<your-vswitch-id>"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Specify a static IP for an internal CLB instance

Annotations: All three annotations are required.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-address-type: "intranet"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vswitch-id: "<your-vswitch-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-ip: "192.168.x.x"
  name: nginx
  namespace: default
spec:
  type: LoadBalancer
  ports:
    - port: 80
      targetPort: 80
      name: http
  selector:
    app: nginx

Create an IPv6 CLB instance

Annotation: alibaba-cloud-loadbalancer-ip-version

The IP version cannot be changed after creation. The cluster's kube-proxy mode must be IPVS.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-ip-version: "ipv6"
  name: nginx
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Add tags to the CLB instance

Annotation: alibaba-cloud-loadbalancer-additional-resource-tags

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-additional-resource-tags: "Key1=Value1,Key2=Value2"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Set the CLB instance name

Annotation: alibaba-cloud-loadbalancer-name

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-name: "your-svc-name"
  name: nginx
spec:
  externalTrafficPolicy: Local
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Assign the CLB instance to a resource group

Annotation: alibaba-cloud-loadbalancer-resource-group-id

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-resource-group-id: "rg-xxxx"
  name: nginx
spec:
  externalTrafficPolicy: Local
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Enable deletion protection

Annotation: alibaba-cloud-loadbalancer-delete-protection

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-delete-protection: "on"
  name: nginx
spec:
  externalTrafficPolicy: Local
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Enable configuration modification protection

Annotation: alibaba-cloud-loadbalancer-modification-protection

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-modification-protection: "ConsoleProtection"
  name: nginx
spec:
  externalTrafficPolicy: Local
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Preserve the CLB instance when deleting a Service

Annotation: alibaba-cloud-loadbalancer-preserve-lb-on-delete

When enabled, a Warning event of type PreservedOnDelete appears during Service synchronization — check for this event to confirm the annotation is active.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-preserve-lb-on-delete: "true"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Set a hostname for the Service

Annotations: Both annotations are required.

After adding this annotation:

• The Service's EXTERNAL-IP changes from the CLB IP to the hostname you specified.

• Traffic from inside the cluster routes through the CLB before forwarding back to the cluster. For TCP or UDP listeners, this may cause loopback issues. See Clients cannot access load balancer.

• The annotation does not automatically bind a domain name to the CLB. To bind a domain, purchase one on the Domain Names page. See Purchase a domain name.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-hostname: "<your-service-hostname>"
  name: nginx-svc
  namespace: default
spec:
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Expected output:

NAME         TYPE           CLUSTER-IP       EXTERNAL-IP            PORT(S)                      AGE
nginx-svc    loadBalancer   47.100.XX.XX     www.example.com        80:30248/TCP,443:32670/TCP   10s

Set the scheduling algorithm

Annotation: alibaba-cloud-loadbalancer-scheduler

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-scheduler: "wrr"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Configure an access control list

Annotations: All three annotations are required. Before applying, create an access control policy group in the CLB console and record its ACL ID.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-acl-status: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-acl-id: "<your-acl-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-acl-type: "white"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Configure session persistence for TCP listeners

Annotation: alibaba-cloud-loadbalancer-persistence-timeout

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-persistence-timeout: "1800"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Configure session persistence for HTTP and HTTPS listeners

Annotations: All four annotations are required when inserting cookies. Applies only to HTTP and HTTPS listeners. If multiple HTTP or HTTPS ports are configured, the setting applies to all of them.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-sticky-session: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-sticky-session-type: "insert"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-cookie-timeout: "1800"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Redirect HTTP to HTTPS

Port forwarding redirects HTTP requests to an HTTPS port. All three annotations are required.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "https:443,http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-cert-id: "<your-cert-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-forward-port: "80:443"
  name: nginx
  namespace: default
spec:
  ports:
  - name: https
    port: 443
    protocol: TCP
    targetPort: 80
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Create a UDP listener

apiVersion: v1
kind: Service
metadata:
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: UDP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Create an HTTP listener

Annotation: alibaba-cloud-loadbalancer-protocol-port

Health checks for HTTP listeners are disabled by default. Configure HTTP or TCP health checks to ensure backend service availability.

When accessing the Service via the CLB IP from inside the cluster, traffic may be intercepted internally. To force traffic through the CLB, add the alibaba-cloud-loadbalancer-hostname annotation. See Notes on accessing the External IP of a LoadBalancer Service from inside the cluster.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Create an HTTPS listener

Annotations: Both annotations are required. HTTPS requests are decrypted at the CLB layer and forwarded to backend Pods as HTTP.

Health checks for HTTPS listeners are disabled by default. Configure HTTP or TCP health checks to ensure backend service availability.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "https:443"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-cert-id: "<your-cert-id>"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "https:443"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-cert-id: "<your-cert-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-domain-extensions: "<domain-1>:<cert-id-1>,<domain-2>:<cert-id-2>"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Configure a TLS security policy

Annotations: All three annotations are required. Applies only to HTTPS listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "https:443,http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-cert-id: "<your-cert-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-tls-cipher-policy: "tls_cipher_policy_1_2"
  name: nginx
  namespace: default
spec:
  ports:
  - name: https
    port: 443
    protocol: TCP
    targetPort: 443
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Configure both TCP and UDP for a single listener

Requires Kubernetes v1.24 or later. To upgrade, see Upgrade an ACK cluster.

apiVersion: v1
kind: Service
metadata:
  name: nginx
  namespace: default
spec:
  ports:
  - name: tcp
    port: 80
    protocol: TCP
    targetPort: 80
  - name: udp
    port: 80
    protocol: UDP
    targetPort: 81
  selector:
    app: nginx
  sessionAffinity: None
  type: LoadBalancer

Configure Proxy Protocol

Annotation: alibaba-cloud-loadbalancer-proxy-protocol

Applies to TCP and UDP listeners. Proxy Protocol passes the client's source IP to the backend server.

When accessing a Service through the CLB IP from inside the cluster, traffic may be intercepted. See Notes on accessing the External IP of a LoadBalancer Service from inside the cluster.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-proxy-protocol: "on"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Configure connection draining

Annotations: Both annotations are required. Applies only to TCP and UDP listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-connection-drain: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-connection-drain-timeout: "30"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Add forwarded request headers

Annotations: Applies only to HTTP and HTTPS listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-xforwardedfor-proto: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-xforwardedfor-slbport: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-xforwardedfor-clientsrcport: "on"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Set the idle connection timeout

Annotations: Applies only to HTTP and HTTPS listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-idle-timeout: "30"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Set the request timeout

Annotations: Applies only to HTTP and HTTPS listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-request-timeout: "60"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Set the connection timeout

Annotation: alibaba-cloud-loadbalancer-established-timeout

Applies only to TCP listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-established-timeout: "60"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Disable HTTP/2

Annotations: Applies only to HTTPS listeners.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "https:443"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-cert-id: "<your-cert-id>"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-http2-enabled: "off"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Configure health checks for TCP listeners

All annotations are required. TCP port health checks are enabled by default.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-switch: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-type: "tcp"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-connect-timeout: "8"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-healthy-threshold: "4"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-unhealthy-threshold: "4"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-interval: "3"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Configure health checks for UDP listeners

All annotations are required. UDP port health checks are enabled by default.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-switch: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-interval: "5"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-connect-timeout: "10"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-healthy-threshold: "3"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-unhealthy-threshold: "3"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: UDP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Disable health checks for TCP and UDP listeners

Annotation: alibaba-cloud-loadbalancer-health-check-switch

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-switch: "off"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Configure HTTP health checks

Applies to HTTP and TCP listeners. All annotations are required.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-flag: "on"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-type: "http"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-uri: "/test/index.html"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-healthy-threshold: "4"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-unhealthy-threshold: "4"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-timeout: "10"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-interval: "3"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-protocol-port: "http:80"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-httpcode: "http_4xx"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-domain: "www.aliyun.com"
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-health-check-method: "head"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Filter backend servers by node label

Annotation: alibaba-cloud-loadbalancer-backend-label

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-backend-label: "failure-domain.beta.kubernetes.io/zone=ap-southeast-5a"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer

Use only nodes running Pods as backend servers

Set externalTrafficPolicy to Local to attach only the nodes where Pods are scheduled, instead of all cluster nodes.

Local mode requires the scheduling algorithm to be wrr. For CCM v1.9.3.164-g2105d2e-aliyun and later, node weights are automatically calculated based on Pod count. See How are node weights automatically set in Local mode?

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-scheduler: "wrr"
  name: nginx
  namespace: default
spec:
  externalTrafficPolicy: Local
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer

Remove unschedulable nodes from the backend server group

Annotation: alibaba-cloud-loadbalancer-remove-unscheduled-backend

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-remove-unscheduled-backend: "on"
  name: nginx
spec:
  externalTrafficPolicy: Local
  ports:
  - name: http
    port: 30080
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Use Pod ENIs as backend servers

Annotation: backend-type

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/backend-type: "eni"
  name: nginx
spec:
  ports:
  - name: http
    port: 30080
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx
  type: LoadBalancer

Reuse an existing vServer group

Annotation: alibaba-cloud-loadbalancer-vgroup-port

Reuse an existing vServer group. Effective only when reusing an existing CLB instance. For a usage example, see Deploy services across clusters by reusing an existing CLB instance.

Set the traffic weight for the Service

Annotation: alibaba-cloud-loadbalancer-weight

When multiple Services share the same CLB instance, set the traffic weight for the current Service. Effective only when reusing an existing vServer group. For a usage example, see Deploy services across clusters by reusing an existing CLB instance.

Ignore backend server weight updates

Annotation: alibaba-cloud-loadbalancer-ignore-weight-update

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-ignore-weight-update: "on"
  name: nginx
  namespace: default
spec:
  ports:
  - port: 443
    protocol: TCP
    targetPort: 443
  selector:
    run: nginx
  type: LoadBalancer