Publish Cluster Services with Kube-vip

You can use kube-vip to provide a virtual IP address for your cluster and use it to expose a service of type LoadBalancer on the external network. You can have kube-vip dynamically request IP addresses or use a static IP address.

Kube-vip supports DHCP environments and can request additional IP address from the DHCP server automatically. Using kube-vip, you can expose services inside your cluster externally with a virtual IP address even if you do not have control over your host's network. Kube-vip can also act as a load balancer for both your control plane and Kubernetes services of type LoadBalancer.

Limitations

Kube-vip has many environment variables you can use to customize its behavior. You can specify values for the environment variables with the cluster.kubevipArgs parameter. For a complete list of environment variables in kube-vip, refer to kube-vip documentation. However, Palette has configured values for the following parameters and they cannot be changed:

Environment Variable	Description	Example Value
vip_arp	Enables ARP broadcasts from leader.	"true"
port	Specifies the port number that kube-vip will use.	"6443"
vip_cidr	Sets the CIDR notation for the Virtual IP. A value of 32 denotes a single IP address in IPv4.	"32"
cp_enable	Enables kube-vip control plane functionality.	"true"
cp_namespace	The namespace where the lease will reside.	"kube-system"
vip_ddns	Enables Dynamic DNS support.	"{{ .DDNS}}"
vip_leaderelection	Enables Kubernetes LeaderElection.	"true"
vip_leaseduration	Sets the lease duration in seconds.	"30"
vip_renewdeadline	Specifies the deadline in seconds for renewing the lease.	"20"
vip_retryperiod	Number of times the leader will hold the lease for.	"4"
address	Template placeholder for the virtual IP address.	"{{ .VIP}}"

Prerequisites

• At least one Edge device with x86_64 or AMD64 processor architecture registered in your Palette account

Enablement

1. Log in to Palette.

2. From the left Main Menu click **Clusters ** and select Add a New Cluster.

3. Choose Edge Native for the cluster type and click Start Edge Native Configuration.

4. Give the cluster a name, description, and tags. Click on Next.

5. Select the cluster profile that you plan to use to deploy your cluster with. Click Next.

6. In the Parameters step, click on the Kubernetes layer of your profile. In the YAML file for the Kubernetes layer of your cluster profile, add the following parameters.

   cluster:
     kubevipArgs:
       vip_interface: "INTERFACE_NAME"
       svc_enable: true
       vip_servicesinterface: "INTERFACE_NAME"

   These are kube-vip environment variables that enable kube-vip to provide load balancing services for Kubernetes services and specify which network interface will be used by kube-vip for handling traffic to the Kubernetes API server and Kubernetes services. The following table provides you guidance on how to choose the values for each parameter:

Parameter	Description
vip_interface	Specifies the Network Interface Controller (NIC) that kube-vip will use for handling traffic to the Kubernetes API. If you do not specify vip_serviceinterface, kube-vip will also use this interface for handling traffic to LoadBalancer-type services.
svc_enable	Enables kube-vip to handle traffic for services of type LoadBalancer.
vip_serviceinterface	Specifies the NIC that kube-vip will use for handling traffic to LoadBalancer-type services. If your cluster has network overlay enabled, or if your host has multiple NICs and you want to publish services on a different NIC than the one used by Kubernetes, you should specify the name of the NIC as the value of this parameter. If this parameter is not specified and you have set svc_enable to true, kube-vip will use the NIC you specified in vip_interface to handle traffic to LoadBalancer-type services.

8. Next, in layer of your cluster profile that has the service you want to expose, add two parameters loadBalancerIP: IP_ADDRESS and loadBalancerClass: kube-vip.io/kube-vip-class to the service spec. The following example manifest displays the usage of these two parameters.

If you are deploying in a DHCP environment, use 0.0.0.0 as the value for the loadBalancerIP parameter. If you want kube-vip to use a static IP, specify the IP address and make sure it's unused by other hosts in the network. The following example manifest displays the usage of these two parameters.

apiVersion: v1
kind: Service
metadata:
  name: http-app-svc
  namespace: myapp
spec:
  loadBalancerIP: 0.0.0.0
  loadBalancerClass: kube-vip.io/kube-vip-class
  ports:
    - port: 80
      protocol: TCP
      targetPort: http
  selector:
    app.kubernetes.io/name: http-app
  type: LoadBalancer

9. Click Next and finish the rest of the configurations. For more information, refer to Create Cluster Definition.

When the cluster finishes deploying, kube-vip adds an annotation named kube-vip.io/requestedIP to the Service resource to document which IP address it has received from the external network. Whenever kube-vip restarts, it will attempt to re-request the same IP address for that service. You can remove the annotation to make kube-vip request a fresh address with the following command. Replace SERVICE_NAME with the name of your service, and make sure to include the minus symbol- at the end of the annotation.

kubectl annotate service SERVICE_NAME kube-vip.io/requestedIP-

Validation

Use the following steps to validate that kube-vip has been set up correctly and is performing load balancing services for your cluster.

1. Access the cluster via kubectl CLI. For more information, refer to Access Cluster with CLI.
2. Issue the command kubectl get service SERVICE_NAME and replace SERVICE_NAME with the name of the service you configure with kube-vip. The output of the command displays the external IP address that kube-vip has received from the external network or the IP address you specified in the loadBalancerIP parameter.

kubectl get service http-app-svc

NAME           TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
http-app-svc   LoadBalancer   10.100.200.10   10.10.1.100   80:30720/TCP   5m

In the above example, the external IP 10.10.1.100 is the IP address that kube-vip received from the DHCP server or the IP address you specified in the loadBalancerIP parameter.