Kubernetes Cluster on Classic Infra

Create your cluster on a classic compute, networking, and storage environment in IBM Cloud infrastructure

This guide describes how to create a Kubernetes cluster with IBM Cloud Kubernetes Service.

IBM Cloud Kubernetes Service provides powerful tools and services to help deploy highly available containerized apps in Kubernetes clusters and to automate, isolate, secure, manage, and monitor your workloads across zones or regions.

Prerequisites

  1. IBMid

    To get started, first go to IBM Cloud to create your IBMid if you do not have one.

  2. Installing the IBM Cloud CLI

    Follow the instructions in this Getting started with the IBM Cloud CLI guide to install the IBM Cloud CLI.

  3. Installing the IBM Cloud Kubernetes Service plug-in with the command

    ibmcloud plugin install container-service

    Refer to this link for more info on IBM Cloud Kubernetes Service CLI.

  4. Authenticating with IBM Cloud

    ibmcloud login

    Use your registered email and password for your IBMid to log in to IBM Cloud.

Connecting to an existing cluster

If you have an existing cluster, use it to install Kubeflow as far as it meets the minimum system requirement.

Get the Kubeconfig file:

ibmcloud ks cluster config --cluster $CLUSTER_NAME

From here on, go to Install Kubeflow on IKS for more information.

Create and setup a new cluster

  • Use a classic provider if you want to try out Kubeflow.
  • Use a vpc-gen2 provider if you are familiar with Cloud networking and want to deploy Kubeflow on a secure environment.

A classic provider exposes each cluster node to the public internet and therefore has a relatively simpler networking setup. Services exposed using Kubernetes NodePort need to be secured using authentication mechanism.

To create a cluster with vpc-gen2 provider, follow the Create a cluster on IKS with a vpc-gen2 provider guide.

The next section will explain how to create and set up a new IBM Cloud Kubernetes Service (IKS)

Setting environment variables

Choose the region and the worker node provider for your cluster, and set the environment variables.

export KUBERNETES_VERSION=1.21
export CLUSTER_ZONE=dal13
export WORKER_NODE_PROVIDER=classic
export CLUSTER_NAME=kubeflow

where:

  • KUBERNETES_VERSION specifies the Kubernetes version for the cluster. Run ibmcloud ks versions to see the supported Kubernetes versions. If this environment variable is not set, the cluster will be created with the default version set by IBM Cloud Kubernetes Service. Refer to Minimum system requirements and choose a Kubernetes version compatible with the Kubeflow release to be deployed.
  • CLUSTER_ZONE identifies the regions or location where cluster will be created. Run ibmcloud ks locations to list supported IBM Cloud Kubernetes Service locations. For example, choose dal13 to create your cluster in the Dallas (US) data center.
  • WORKER_NODE_PROVIDER specifies the kind of IBM Cloud infrastructure on which the Kubernetes worker nodes will be created. The classic type supports worker nodes with GPUs. There are other worker nodes providers including vpc-classic and vpc-gen2 where zone names and worker flavors will be different. Run ibmcloud ks zones --provider classic to list zone names for classic provider and set the CLUSTER_ZONE accordingly.
  • CLUSTER_NAME must be lowercase and unique among any other Kubernetes clusters in the specified ${CLUSTER_ZONE}.

Notice: Refer to Creating clusters in the IBM Cloud documentation for additional information on how to set up other providers and zones in your cluster.

Choosing a worker node flavor

The worker node flavor name varies from zones and providers. Run ibmcloud ks flavors --zone ${CLUSTER_ZONE} --provider ${WORKER_NODE_PROVIDER} to list available flavors.

For example, the following are some worker node flavors supported in the dal13 zone with a classic node provider.

ibmcloud ks flavors --zone dal13 --provider classic

Example output:

OK
For more information about these flavors, see 'https://ibm.biz/flavors'
Name                      Cores   Memory   Network Speed   OS             Server Type   Storage      Secondary Storage   Provider
b2c.16x64                 16      64GB     1000Mbps        UBUNTU_16_64   virtual       25GB         100GB               classic
b2c.32x128                32      128GB    1000Mbps        UBUNTU_16_64   virtual       25GB         100GB               classic
b2c.4x16                  4       16GB     1000Mbps        UBUNTU_16_64   virtual       25GB         100GB               classic
b2c.56x242                56      242GB    1000Mbps        UBUNTU_16_64   virtual       25GB         100GB               classic
b2c.8x32                  8       32GB     1000Mbps        UBUNTU_16_64   virtual       25GB         100GB               classic
b3c.16x64                 16      64GB     1000Mbps        UBUNTU_18_64   virtual       25GB         100GB               classic
b3c.32x128                32      128GB    1000Mbps        UBUNTU_18_64   virtual       25GB         100GB               classic
b3c.4x16                  4       16GB     1000Mbps        UBUNTU_18_64   virtual       25GB         100GB               classic
b3c.56x242                56      242GB    1000Mbps        UBUNTU_18_64   virtual       25GB         100GB               classic
b3c.8x32                  8       32GB     1000Mbps        UBUNTU_18_64   virtual       25GB         100GB               classic
...

Choose a flavor that will work for your applications. For the purpose of the Kubeflow deployment, the recommended configuration for a cluster is at least 8 vCPU cores with 16GB memory. Hence you can either choose the b3c.8x32 flavor to create a one-worker-node cluster or choose the b3c.4x16 flavor to create a two-worker-node cluster. Keep in mind that you can always scale the cluster by adding more worker nodes should your application scales up.

Now, set the environment variable with the worker node flavor of your choice:

export WORKER_NODE_FLAVOR=b3c.4x16

Creating an IBM Cloud Kubernetes cluster

Run with the following command to create a cluster:

Replace the workers parameter above with the desired number of worker nodes.

If you’re starting in a fresh account with no public and private VLANs, they are created automatically for you when creating a Kubernetes cluster with worker nodes provider classic for the first time. If you already have VLANs configured in your account, retrieve them via ibmcloud ks vlans --zone ${CLUSTER_ZONE} and include the public and private VLAN ids (set in the PUBLIC_VLAN_ID and PRIVATE_VLAN_ID environment variables) in the command.

ibmcloud ks cluster create ${WORKER_NODE_PROVIDER} \
  --name=$CLUSTER_NAME \
  --zone=$CLUSTER_ZONE \
  --version=${KUBERNETES_VERSION} \
  --flavor ${WORKER_NODE_FLAVOR} \
  --workers=2 \
  --private-vlan ${PRIVATE_VLAN_ID} \
  --public-vlan ${PUBLIC_VLAN_ID}

Wait until the cluster is deployed and configured. It can take a while for the cluster to be ready. Run with following command to periodically check the state of your cluster. Your cluster is ready when the state is normal.

ibmcloud ks clusters --provider ${WORKER_NODE_PROVIDER} |grep ${CLUSTER_NAME} |awk '{print "Name:"$1"\tState:"$3}'

Verifying the cluster

To use the created cluster, switch the Kubernetes context to point to the cluster with the command

ibmcloud ks cluster config --cluster ${CLUSTER_NAME}

Make sure all worker nodes are up with the command below

kubectl get nodes

and make sure all the nodes are in Ready state.

Delete the cluster

Delete the cluster including it’s storage:

ibmcloud ks cluster rm --force-delete-storage -c ${CLUSTER_NAME}