Using Annotations to Configure Load Balancing

You can add annotations to a YAML file to use some CCE advanced functions. This section describes the available annotations when a LoadBalancer service is created.

Interconnection with ELB
Sticky Session
Health Check
HTTP Protocol
Dynamic Adjustment of the Weight of the Backend ECS
Pass-through Capability
Host Network
Timeout

Interconnection with ELB

**Table 1** Annotations for interconnecting with ELB
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.class	String	Select a proper load balancer type. union: shared load balancer performance: dedicated load balancer, which can be used only in clusters of v1.17 and later.	v1.9 or later
kubernetes.io/elb.id	String	Mandatory when an existing load balancer is to be associated. ID of a load balancer. How to obtain: On the management console, click Service List, and choose Networking > Elastic Load Balance. Click the name of the target load balancer. On the Summary tab page, find and copy the ID. NOTE: The system preferentially connects to the load balancer based on the kubernetes.io/elb.id field. If this field is not specified, the spec.loadBalancerIP field is used (optional and available only in 1.23 and earlier versions). Do not use the spec.loadBalancerIP field to connect to the load balancer. This field will be discarded by Kubernetes. For details, see Deprecation.	v1.9 or later
kubernetes.io/elb.autocreate	Table 9	Mandatory when load balancers are automatically created. Example: If a public network load balancer will be automatically created, set this parameter to the following value: {"type":"public","bandwidth_name":"cce-bandwidth-1551163379627","bandwidth_chargemode":"bandwidth","bandwidth_size":5,"bandwidth_sharetype":"PER","eip_type":"5_bgp","name":"james"} If a private network load balancer will be automatically created, set this parameter to the following value: {"type":"inner","name":"A-location-d-test"}	v1.9 or later
kubernetes.io/elb.enterpriseID	String	Optional when load balancers are automatically created. Clusters of v1.15 and later versions support this field. In clusters earlier than v1.15, load balancers are created in the default project by default. This parameter indicates the ID of the enterprise project in which the ELB load balancer will be created. If this parameter is not specified or is set to 0, resources will be bound to the default enterprise project. How to obtain: Log in to the EPS console. In the navigation pane, choose Project Management. In the enterprise project list, click the name of the enterprise project to be added. On the enterprise project details page, copy the project ID.	v1.15 or later
kubernetes.io/elb.subnet-id	String	Optional when load balancers are automatically created. ID of the subnet where the cluster is located. The value can contain 1 to 100 characters. Mandatory when a cluster of v1.11.7-r0 or earlier is to be automatically created. Optional for clusters later than v1.11.7-r0.	Mandatory for versions earlier than v1.11.7-r0 Discarded in versions later than v1.11.7-r0
kubernetes.io/elb.lb-algorithm	String	Specifies the load balancing algorithm of the backend server group. The default value is ROUND_ROBIN. Options: ROUND_ROBIN: weighted round robin algorithm LEAST_CONNECTIONS: weighted least connections algorithm SOURCE_IP: source IP hash algorithm NOTE: If this parameter is set to SOURCE_IP, the weight setting (weight field) of backend servers bound to the backend server group is invalid, and sticky session cannot be enabled.	v1.9 or later

The following shows how to use the preceding annotations:

Associating an existing load balancer. For details, see Using kubectl to Create a Service (Using an Existing Load Balancer).

apiVersion: v1 
kind: Service 
metadata: 
  name: nginx
  annotations:
    kubernetes.io/elb.id: <your_elb_id>                         # ELB ID. Replace it with the actual value.
    kubernetes.io/elb.class: performance                        # Load balancer type
    kubernetes.io/elb.lb-algorithm: ROUND_ROBIN                   # Load balancer algorithm
spec:
  selector: 
     app: nginx
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  type: LoadBalancer

Automatically creating a load balancer. For details, see Using kubectl to Create a Service (Automatically Creating a Load Balancer).

Shared load balancer:

apiVersion: v1 
kind: Service 
metadata: 
  annotations:   
    kubernetes.io/elb.class: union
    kubernetes.io/elb.autocreate: '{
      "type": "public",
      "bandwidth_name": "cce-bandwidth-1551163379627",
      "bandwidth_chargemode": "bandwidth",
      "bandwidth_size": 5,
      "bandwidth_sharetype": "PER",
      "eip_type": "5_bgp"
    }'
    kubernetes.io/elb.enterpriseID: '0'               # ID of the enterprise project to which the load balancer belongs
    kubernetes.io/elb.lb-algorithm: ROUND_ROBIN     # Load balancer algorithm
  labels: 
    app: nginx 
  name: nginx 
spec: 
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  selector: 
    app: nginx 
  type: LoadBalancer

Dedicated load balancer:

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
  namespace: default
  annotations:
    kubernetes.io/elb.class: performance
    kubernetes.io/elb.autocreate: '{
      "type": "public",
      "bandwidth_name": "cce-bandwidth-1626694478577",
      "bandwidth_chargemode": "bandwidth",
      "bandwidth_size": 5,
      "bandwidth_sharetype": "PER",
      "eip_type": "5_bgp",
      "available_zone": [
         ""
      ],
      "l4_flavor_name": "L4_flavor.elb.s1.small"
    }'
    kubernetes.io/elb.enterpriseID: '0'               # ID of the enterprise project to which the load balancer belongs
    kubernetes.io/elb.lb-algorithm: ROUND_ROBIN     # Load balancer algorithm
spec:
  selector:
    app: nginx
  ports:
  - name: cce-service-0
    targetPort: 80
    nodePort: 0
    port: 80
    protocol: TCP
  type: LoadBalancer

Sticky Session

**Table 2** Annotations for sticky session
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.session-affinity-mode	String	Source IP address-based sticky session is supported. That is, access requests from the same IP address are forwarded to the same backend server. Disabling sticky session: Do not configure this parameter. Enabling sticky session: Set this parameter to SOURCE_IP, indicating that the sticky session is based on the source IP address. NOTE: When kubernetes.io/elb.lb-algorithm is set to SOURCE_IP (source IP address algorithm), sticky session cannot be enabled.	v1.9 or later
kubernetes.io/elb.session-affinity-option	Table 12	Sticky session timeout.	v1.9 or later

The following shows how to use the preceding annotations:

apiVersion: v1 
kind: Service 
metadata: 
  name: nginx
  annotations:
    kubernetes.io/elb.id: <your_elb_id>                         # ELB ID. Replace it with the actual value.
    kubernetes.io/elb.class: union                   # Load balancer type
    kubernetes.io/elb.session-affinity-mode: SOURCE_IP          # The sticky session type is source IP address.
    kubernetes.io/elb.session-affinity-option: '{"persistence_timeout": "30"}'     # Stickiness duration (min)
spec:
  selector: 
     app: nginx
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  type: LoadBalancer

Health Check

**Table 3** Annotations for health check
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.health-check-flag	String	Whether to enable the ELB health check. Enabling health check: Leave blank this parameter or set it to on. Disabling health check: Set this parameter to off. If this parameter is enabled, the kubernetes.io/elb.health-check-option field must also be specified at the same time.	v1.9 or later
kubernetes.io/elb.health-check-option	Table 10	ELB health check configuration items.	v1.9 or later
kubernetes.io/elb.health-check-options	Table 11	ELB health check configuration item. Each Service port can be configured separately, and you can configure only some ports. NOTE: kubernetes.io/elb.health-check-option and kubernetes.io/elb.health-check-options cannot be configured at the same time.	v1.19.16-r5 or later v1.21.8-r0 or later v1.23.6-r0 or later v1.25.2-r0 or later

The following shows how to use kubernetes.io/elb.health-check-option:

apiVersion: v1 
kind: Service 
metadata: 
  name: nginx
  annotations:
    kubernetes.io/elb.id: <your_elb_id>                         # ELB ID. Replace it with the actual value.
    kubernetes.io/elb.class: union                   # Load balancer type
    kubernetes.io/elb.health-check-flag: 'on'                   # Enable the ELB health check function.
    kubernetes.io/elb.health-check-option: '{
      "protocol":"TCP",
      "delay":"5",
      "timeout":"10",
      "max_retries":"3"
    }'
spec:
  selector: 
     app: nginx
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  type: LoadBalancer

For details about how to use kubernetes.io/elb.health-check-options, see Configuring Health Check for Multiple Ports.

HTTP Protocol

**Table 4** Annotations for using HTTP protocols
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.protocol-port	String	Layer-7 forwarding configuration port used by the Service.	v1.19.16 or later
kubernetes.io/elb.cert-id	String	HTTP certificate used by the Service for Layer-7 forwarding.	v1.19.16 or later

For details about the application scenarios, see Service Using HTTP.

Dynamic Adjustment of the Weight of the Backend ECS

**Table 5** Annotations for dynamically adjusting the weight of the backend ECS
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.adaptive-weight	String	Dynamically adjusts the weight of the load balancer backend ECS based on pods. The requests received by each pod are more balanced. true: enabled false: disabled This parameter applies only to clusters of v1.21 or later and is invalid in passthrough networking.	v1.21 or later

The following shows how to use the preceding annotations:

apiVersion: v1 
kind: Service 
metadata: 
  name: nginx
  annotations:
    kubernetes.io/elb.id: <your_elb_id>                         # ELB ID. Replace it with the actual value.
    kubernetes.io/elb.class: union                   # Load balancer type
    kubernetes.io/elb.adaptive-weight: 'true'                   # Enable dynamic adjustment of the weight of the backend ECS.
spec:
  selector: 
     app: nginx
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  type: LoadBalancer

Pass-through Capability

**Table 6** Annotations for pass-through capability
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.pass-through	String	Whether the access requests from within the cluster to the Service pass through the ELB load balancer.	v1.19 or later

For details about the application scenarios, see Enabling Passthrough Networking for LoadBalancer Services.

Host Network

**Table 7** Annotations for host network
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/hws-hostNetwork	String	If the pod uses hostNetwork, the ELB forwards the request to the host network after this annotation is used. Options: true: enabled false (default): disabled	v1.9 or later

The following shows how to use the preceding annotations:

apiVersion: v1 
kind: Service 
metadata: 
  name: nginx
  annotations:
    kubernetes.io/elb.id: <your_elb_id>                         # ELB ID. Replace it with the actual value.
    kubernetes.io/elb.class: union                   # Load balancer type
    kubernetes.io/hws-hostNetwork: 'true'                     # The load balancer forwards the request to the host network.
spec:
  selector: 
     app: nginx
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  type: LoadBalancer

Timeout

**Table 8** Annotation for configuring timeout
Parameter	Type	Description	Supported Cluster Version
kubernetes.io/elb.keepalive_timeout	Integer	Timeout for client connections. If there are no requests reaching the load balancer after the timeout duration elapses, the load balancer will disconnect the connection with the client and establish a new connection when there is a new request. Value: For TCP listeners, the value ranges from 10 to 4000 (in seconds). The default value is 300. For HTTP, HTTPS, and TERMINATED_HTTPS listeners, the value ranges from 10 to 4000 (in seconds). The default value is 60. For UDP listeners, this parameter does not take effect.	v1.19.16-r30, v1.21.10-r10, v1.23.8-r10, v1.25.3-r10, and later

For details about the application scenarios, see Configuring Timeout for a LoadBalancer Service.

Data Structure

**Table 9** Data structure of the **elb.autocreate** field
Parameter	Mandatory	Type	Description
name	No	String	Name of the automatically created load balancer. The value can contain 1 to 64 characters. Only letters, digits, underscores (_), hyphens (-), and periods (.) are allowed. Default: cce-lb+service.UID
type	No	String	Network type of the load balancer. public: public network load balancer inner: private network load balancer Default: inner
bandwidth_name	Yes for public network load balancers	String	Bandwidth name. The default value is cce-bandwidth-******. The value can contain 1 to 64 characters. Only letters, digits, underscores (_), hyphens (-), and periods (.) are allowed.
bandwidth_chargemode	No	String	Bandwidth mode. bandwidth: billed by bandwidth traffic: billed by traffic Default: bandwidth
bandwidth_size	Yes for public network load balancers	Integer	Bandwidth size. The default value is 1 to 2000 Mbit/s. Configure this parameter based on the bandwidth range allowed in your region. The minimum increment for bandwidth adjustment varies depending on the bandwidth range. The minimum increment is 1 Mbit/s if the allowed bandwidth does not exceed 300 Mbit/s. The minimum increment is 50 Mbit/s if the allowed bandwidth ranges from 300 Mbit/s to 1000 Mbit/s. The minimum increment is 500 Mbit/s if the allowed bandwidth exceeds 1000 Mbit/s.
bandwidth_sharetype	Yes for public network load balancers	String	Bandwidth sharing mode. PER: dedicated bandwidth
eip_type	Yes for public network load balancers	String	EIP type. 5_bgp: dynamic BGP The specific type varies with regions. For details, see the EIP console.
available_zone	Yes	Array of strings	AZ where the load balancer is located. This parameter is available only for dedicated load balancers.
l4_flavor_name	Yes	String	Flavor name of the layer-4 load balancer. This parameter is available only for dedicated load balancers.
l7_flavor_name	No	String	Flavor name of the layer-7 load balancer. This parameter is available only for dedicated load balancers. The value of this parameter must be the same as that of l4_flavor_name, that is, both are elastic specifications or fixed specifications.
elb_virsubnet_ids	No	Array of strings	Subnet where the backend server of the load balancer is located. If this parameter is left blank, the default cluster subnet is used. Load balancers occupy different number of subnet IP addresses based on their specifications. Therefore, you are not advised to use the subnet CIDR blocks of other resources (such as clusters and nodes) as the load balancer CIDR block. This parameter is available only for dedicated load balancers. Example: "elb_virsubnet_ids": [ "14567f27-8ae4-42b8-ae47-9f847a4690dd" ]

**Table 10** Data structure description of the **elb.health-check-option** field
Parameter	Mandatory	Type	Description
delay	No	String	Initial waiting time (in seconds) for starting the health check. Value range: 1 to 50. Default value: 5
timeout	No	String	Health check timeout, in seconds. Value range: 1 to 50. Default value: 10
max_retries	No	String	Maximum number of health check retries. Value range: 1 to 10. Default value: 3
protocol	No	String	Health check protocol. Value options: TCP or HTTP
path	No	String	Health check URL. This parameter needs to be configured when the protocol is HTTP. Default value: / The value can contain 1 to 10,000 characters.

**Table 11** Data structure description of the **elb.health-check-options** field
Parameter	Mandatory	Type	Description
target_service_port	Yes	String	Port for health check specified by spec.ports. The value consists of the protocol and port number, for example, TCP:80.
monitor_port	No	String	Re-specified port for health check. If this parameter is not specified, the service port is used by default. NOTE: Ensure that the port is in the listening state on the node where the pod is located. Otherwise, the health check result will be affected.
delay	No	String	Initial waiting time (in seconds) for starting the health check. Value range: 1 to 50. Default value: 5
timeout	No	String	Health check timeout, in seconds. Value range: 1 to 50. Default value: 10
max_retries	No	String	Maximum number of health check retries. Value range: 1 to 10. Default value: 3
protocol	No	String	Health check protocol. Default value: protocol of the associated Service Value options: TCP, UDP, or HTTP
path	No	String	Health check URL. This parameter needs to be configured when the protocol is HTTP. Default value: / The value can contain 1 to 10,000 characters.

**Table 12** Data structure of the **elb.session-affinity-option** field
Parameter	Mandatory	Type	Description
persistence_timeout	Yes	String	Sticky session timeout, in minutes. This parameter is valid only when elb.session-affinity-mode is set to SOURCE_IP. Value range: 1 to 60. Default value: 60