Creating Load Balancers in OKS

You can give customers open access to your clusters using OKS load balancers. An OKS load balancer is a kubernetes cluster entry that is responsible for detecting load balancer creation requests in the manifests that are applied to a cluster, creating the corresponding Load Balancing Unit (LBU), and attaching the newly created LBU to your cluster.

For more information about load balancers, see Load Balancing Unit (LBU).

Creating a Load Balancer

To create a load balancer, you have to attach the required annotations to your manifests.

In the following example, we will create a basic load balancer granting HTTPS access to the resources on the cluster.

This micro-application would watch for HTTP requests on the TCP port 80 and return the received request headers as a response:

Response sample

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: echoheaders
  namespace: default
  labels:
    app: echoheaders
spec:
  replicas: 1
  selector:
    matchLabels:
      app: echoheaders
  template:
    metadata:
      labels:
        app: echoheaders
    spec:
      containers:
      - name: echoheaders
        image: gcr.io/google_containers/echoserver:1.10
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: echoheaders-lb-public
  namespace: default
  labels:
    app: echoheaders
  annotations:
    service.beta.kubernetes.io/osc-load-balancer-name: "simple-lb-test"
spec:
  ports:
  - port: 80
    name: http
    protocol: TCP
    targetPort: 8080
  selector:
    app: echoheaders
  type: LoadBalancer

Using Annotations in Your Load Balancers

The table below lists supported annotations for your OKS load balancers.

Lists should be comma-separated unless specified otherwise.

Annotation Mutability Description Default value

service.beta.kubernetes.io/osc-load-balancer-name

The name of the load balancer.

namespace_of_service-name_of_service

If longer that 31 characters, it is truncated.

service.beta.kubernetes.io/osc-load-balancer-scheme

The scheme (or type) of the load balancer.

internet-facing

This value can be set to internet-facing or internal.

service.beta.kubernetes.io/osc-load-balancer-target-node-pools

Yes

The list of node pools to use as backend VMs on the LBU.

For example: worker-pool-1,worker-pool-2, power-nodes-pool.

* (all node pools)

service.beta.kubernetes.io/osc-load-balancer-additional-resource-tags

Yes

The list of key-value pairs which will be recorded as additional tags in the ELB.

For example: Key1=Val1,Key2=Val2,KeyNoVal1=,KeyNoVal2.

None

service.beta.kubernetes.io/osc-load-balancer-source-ranges

Yes

The list of CIDRs allowed to access the load balancer.

service.beta.kubernetes.io/osc-load-balancer-source-ranges

Specifying CIDRs in the spec.LoadBalancerSourceRanges service rather than using this annotation will allow you to use the Kubernetes validator.

Yes

The list of CIDRs allowed to access the load balancer.

0.0.0.0/0 (All IPs)

service.beta.kubernetes.io/osc-load-balancer-healthcheck-interval

Yes

The time between two health check requests (from 5 to 600 seconds).

service.beta.kubernetes.io/osc-load-balancer-healthcheck-healthy-threshold

Yes

The number of health check requests that must succeed consecutively in order to consider the node healthy (from 2 to 10).

service.beta.kubernetes.io/osc-load-balancer-healthcheck-path

Yes

The optional URL path for health check requests, only used with HTTP or HTTPS health check protocols.

For example: /healthz.

None

service.beta.kubernetes.io/osc-load-balancer-healthcheck-port

Yes

The port number for health check requests (from 1 to 65535).

Assigned automatically to the nodePort of the service.

service.beta.kubernetes.io/osc-load-balancer-healthcheck-protocol

Yes

The protocol for health check requests (among HTTP/HTTPS/TCP/SSL).

Assigned automatically to the protocol of the service.

service.beta.kubernetes.io/osc-load-balancer-healthcheck-timeout

Yes

The maximum waiting time for a response before considering the node unhealthy (from 2 to 60 seconds).

service.beta.kubernetes.io/osc-load-balancer-healthcheck-unhealthy-threshold

Yes

The number of health check requests that must fail consecutively in order to consider the node unhealthy (from 2 to 10).

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