Configuring Health Check on Multiple LoadBalancer Service Ports
The health check annotation for LoadBalancer Services has been upgraded from kubernetes.io/elb.health-check-option to kubernetes.io/elb.health-check-options. You can now configure health checks for specific Service ports without affecting other ports. To apply a global health check to all ports, continue using the original annotation.
Constraints
- This function is available in the following versions:
- v1.19: v1.19.16-r5 or later
- v1.21: v1.21.8-r0 or later
- v1.23: v1.23.6-r0 or later
- v1.25: v1.25.2-r0 or later
- Versions later than v1.25
- Either kubernetes.io/elb.health-check-option or kubernetes.io/elb.health-check-options can be configured.
- The target_service_port field is mandatory and must be unique.
Procedure
Configure health checks for different Service ports. The following is an example using the kubernetes.io/elb.health-check-options annotation:
apiVersion: v1
kind: Service
metadata:
name: nginx
namespace: default
labels:
app: nginx
version: v1
annotations:
kubernetes.io/elb.class: union # Load balancer type
kubernetes.io/elb.id: <your_elb_id> # Load balancer ID. Replace it with the actual value.
kubernetes.io/elb.lb-algorithm: ROUND_ROBIN # Load balancer algorithm
kubernetes.io/elb.health-check-flag: 'on' # Enable ELB health check.
kubernetes.io/elb.health-check-options: '[
{
"protocol": "TCP",
"delay": "5",
"timeout": "10",
"max_retries": "3",
"target_service_port": "TCP:1",
"monitor_port": "22"
},
{
"protocol": "HTTP",
"delay": "5",
"timeout": "10",
"max_retries": "3",
"path": "/",
"target_service_port": "TCP:2",
"monitor_port": "22",
"expected_codes": "200"
}
]'
spec:
selector:
app: nginx
version: v1
externalTrafficPolicy: Cluster
ports:
- name: cce-service-0
targetPort: 1
nodePort: 0
port: 1
protocol: TCP
- name: cce-service-1
targetPort: 2
nodePort: 0
port: 2
protocol: TCP
type: LoadBalancer
loadBalancerIP: **.**.**.**
| 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 | Health check interval (s) 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: HTTPS, TLS, gRPC, TCP, UDP, and HTTP To use HTTPS, TLS, or gRPC, you need to use a dedicated load balancer, and the cluster version must be v1.28.15-r90, v1.29.15-r50, v1.30.14-r50, v1.31.14-r10, v1.32.9-r10, v1.33.7-r10, v1.34.3-r0, or later. gRPC and TLS depend on the ELB capabilities. Before using this function, submit a service ticket to enable the required ELB capabilities.
CAUTION: To change the health check protocol (including the switchover between global check and custom check), disable the health check, enable it again, and change the protocol. |
| path | No | String | Health check URL. This parameter needs to be configured when the protocol is HTTP, HTTPS, or gRPC. Default value: / Value range: 1-80 characters |
| expected_codes | No | String | Expected response status code. This parameter is supported only by clusters v1.19.16-r50, v1.21.11-r10, v1.23.9-r10, v1.25.4-r10, v1.27.1-r10, or later. Value:
Default value: 200. The status code ranges from 200 to 599. For gRPC health checks, the default value is 0, and the status code ranges from 0 to 99. This parameter is available only for HTTP, HTTPS, or gRPC. It has no effect on other protocols. |
