IP Address Management (IPAM)

k0rdent provides a flexible IP Address Management (IPAM) system that enables deterministic allocation of IP addresses throughout the cluster lifecycle.

Warning

At the moment only node network is supported

With IPAM enabled, IP addresses can be assigned to both worker and control plane nodes.

Administrators can define address ranges using either CIDR blocks or explicit IP lists, enabling:

• Predictable, conflict-free assignments
• Seamless integration with existing network topologies
• Fine-grained control in multi-tenant or segmented environments

Deploying a Cluster with IPAM

Follow these instructions to configure IPAM for your cluster deployment.

Prerequisites

Ensure the following before configuring IPAM:

• A valid, unused IP space is available (CIDR or static IP list).
• The reserved space must accommodate:
  • One IP per control plane node
  • One IP per worker node

Define IPAM configuration

There are two options for configuring IPAM in k0rdent

Option 1: Use mutual references in ClusterDeployment and ClusterIPAMClaim

To use mutual references, follow these steps:

1. Define a ClusterIPAMClaim

   The ClusterIPAMClaim resource reserves the required IP address space for the cluster. The node network segment can be defined using either a cidr or a static list of ipAddresses.

   apiVersion: k0rdent.mirantis.com/v1beta1
   kind: ClusterIPAMClaim
   metadata:
     name: <claim-name>
     namespace: <namespace>
   spec:
     provider: <provider-name>
     nodeNetwork:
       cidr: <cidr>
       # ipAddresses:
       # - <ip-1>
       # - <ip-2>
     cluster: <cluster-name>
   

   • The cluster field in ClusterIPAMClaim is immutable once set.
   • The cluster field links the claim to a specific ClusterDeployment, ensuring IPs are reserved before provisioning begins.

2. Apply the ClusterIPAMClaim

   To create the claim:

   kubectl apply -f <cluster-ipam-claim-file>.yaml
   

   To verify the claim:

   kubectl get clusteripamclaim <claim-name> -n <namespace>
   

   apiVersion: k0rdent.mirantis.com/v1beta1
   kind: ClusterIPAMClaim
   metadata:
     name: <claim-name>
     namespace: <namespace>
   spec:
     cluster: <cluster-name>
     clusterIPAMRef: <claim-name>
     nodeNetwork:
       cidr: <cidr>
       # ipAddresses:
       # - <ip-1>
       # - <ip-2>
     provider: <provider-name>
   status:
     bound: true
   

   • .spec.clusterIPAMRef: If this field is set, it indicates that the child ClusterIPAM object was successfully created.
   • .status.bound: If true, it means the child ClusterIPAM was successfully reconciled and the defined addresses were allocated.

3. Define a ClusterDeployment

   Finally, define the ClusterDeployment.

   apiVersion: k0rdent.mirantis.com/v1beta1
   kind: ClusterDeployment
   metadata:
     name: <cluster-name>
     namespace: <namespace>
   spec:
     template: <template-name>
     credential: <provider-credential-name>
     dryRun: <"true" | "false">  # Optional; defaults to "false"
     config:
       <cluster-configuration>
     ipamClaim:
       ref: <claim-name>
   

Option 2: Use inline IPAM configuration in ClusterDeployment

The IPAM configuration can also be defined inline within the ClusterDeployment resource as follows:

1. Define a ClusterDeployment

   First, define the ClusterDeployment:

   apiVersion: k0rdent.mirantis.com/v1beta1
   kind: ClusterDeployment
   metadata:
     name: <cluster-name>
     namespace: <namespace>
   spec:
     template: <template-name>
     credential: <provider-credential-name>
     dryRun: <"true" | "false">  # Optional; defaults to "false"
     config:
       <cluster-configuration>
     ipamClaim:
       spec:
         provider: <provider-name>
         nodeNetwork:
           cidr: <cidr>
           # ipAddresses:
           # - <ip-1>
           # - <ip-2>
   

2. Apply the ClusterDeployment:

   kubectl apply -f <cluster-deployment-file>.yaml
   

3. Verify IPAM

   The specified IPAM settings will be used to allocate IP addresses during provisioning. Keep in mind that cluster provisioning will not proceed until IPAM resources are ready and addresses are allocated.

   To inspect the resulting ClusterIPAM resource:

   kubectl get -n <namespace> ClusterIPAM <claim-name>
   

   apiVersion: k0rdent.mirantis.com/v1beta1
   kind: ClusterIPAM
   metadata:
     name: <cluster-ipam-name>
     namespace: <namespace>
   spec:
     provider: <provider-name>
     clusterIPAMClaimRefs: <cluster-ipam-claim-name>
   status:
     phase: Bound
     providerData:
       <provider data>