Configuring Health Check on Multiple Ports of a LoadBalancer Service¶
The annotation field related to the health check of the LoadBalancer Service is upgraded from Kubernetes.io/elb.health-check-option to Kubernetes.io/elb.health-check-options. Each Service port can be configured separately, and you can configure only some ports. If the port protocol does not need to be configured separately, the original annotation field is still available and does not need to be modified.
Notes and Constraints¶
This feature 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.
For a TCP port, the health check protocol can only be TCP or HTTP. For a UDP port, the health check protocol must be UDP.
Procedure¶
The following is an example of 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": "200-399,401,404"
}
]'
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: TCP, UDP, or HTTP |
path | No | String | Health check URL. This parameter needs to be configured when the protocol is HTTP. Default value: / Value range: 1-80 characters |