Create or access an IBM Cloud Kubernetes cluster on a VPC

Instructions for creating or connecting to a Kubernetes cluster on IBM Cloud vpc-gen2

Create and setup a new cluster

Follow these steps to create and setup a new IBM Cloud Kubernetes Service(IKS) cluster on vpc-gen2 provider.

A vpc-gen2 cluster does not expose each node to the public internet directly and thus has more secure and more complex network setup. It is recommended setup for secured production use cases of Kubeflow.

Setting environment variables

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

export KUBERNERTES_VERSION=1.18
export CLUSTER_ZONE=us-south-3
export CLUSTER_NAME=kubeflow-vpc

where:

  • KUBERNETES_VERSION: Run ibmcloud ks versions to see the supported Kubernetes versions. Refer to Supported version matrix.
  • CLUSTER_ZONE: Run ibmcloud ks locations to list supported zones. For example, choose us-south-3 to create your cluster in the Dallas (US) data center.
  • 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 nodes flavor name varies from zones and providers. Run ibmcloud ks flavors --zone ${CLUSTER_ZONE} --provider vpc-gen2 to list available flavors.

Below are some examples of flavors supported in the us-south-3 zone with vpc-gen2 node provider:

ibmcloud ks flavors --zone us-south-3 --provider vpc-gen2

Example output:

For more information about these flavors, see 'https://ibm.biz/flavors'
Name         Cores   Memory   Network Speed   OS             Server Type   Storage   Secondary Storage   Provider   
bx2.16x64    16      64GB     16Gbps          UBUNTU_18_64   virtual       100GB     0B                  vpc-gen2   
bx2.2x8†     2       8GB      4Gbps           UBUNTU_18_64   virtual       100GB     0B                  vpc-gen2   
bx2.32x128   32      128GB    16Gbps          UBUNTU_18_64   virtual       100GB     0B                  vpc-gen2   
bx2.48x192   48      192GB    16Gbps          UBUNTU_18_64   virtual       100GB     0B                  vpc-gen2   
bx2.4x16     4       16GB     8Gbps           UBUNTU_18_64   virtual       100GB     0B                  vpc-gen2   
...

The recommended configuration for a cluster is at least 8 vCPU cores with 16GB memory. Hence, we recommend bx2.4x16 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 flavor you choose.

export WORKER_NODE_FLAVOR=bx2.4x16

Create an IBM Cloud Kubernetes cluster for vpc-gen2 infrastructure

Creating a vpc-gen2 based cluster needs a VPC, a subnet and a public gateway attached to it. Fortunately, this is a one time setup. Future vpc-gen2 clusters can reuse the same VPC/subnet(with attached public-gateway).

  1. Begin with installing a vpc-infrastructure plugin:

    ibmcloud plugin install vpc-infrastructure
    

    Refer to this link, for more information.

  2. Target vpc-gen 2 to access gen 2 VPC resources:

    ibmcloud is target --gen 2
    

    Verify that the target is correctly set up:

    ibmcloud is target
    

    Example output:

    Target Generation: 2
    
  3. Create or use an existing VPC:

    a) Use an existing VPC:

    ibmcloud is vpcs
    

    Example output:

    Listing vpcs for generation 2 compute in all resource groups and region ...
    ID                                          Name                Status      Classic access   Default network ACL                                    Default security group                                 Resource group   
    r006-hidden-68cc-4d40-xxxx-4319fa3gxxxx   my-vpc1              available   false            husker-sloping-bee-resize                              blimp-hasty-unaware-overflow                           kubeflow   
    

    If the above list contains the VPC that can be used to deploy your cluster - make a note of its ID.

    b) To create a new VPC, proceed as follows:

    ibmcloud is vpc-create my-vpc
    

    Example output:

    Creating vpc my-vpc in resource group kubeflow under account IBM as ...
                                                         
    ID                                             r006-hidden-68cc-4d40-xxxx-4319fa3fxxxx   
    Name                                           my-vpc   
    ...  
    

    Save the ID in a variable VPC_ID as follows, so that we can use it later.

    export VPC_ID=r006-hidden-68cc-4d40-xxxx-4319fa3fxxxx
    
  4. Create or use an existing subnet:

    a) To use an existing subnet:

    ibmcloud is subnets
    

    Example output:

    Listing subnets for generation 2 compute in all resource groups and region ...
    ID                                          Name                      Status      Subnet CIDR       Addresses     ACL                                                    Public Gateway                             VPC                 Zone         Resource group   
    0737-27299d09-1d95-4a9d-a491-a6949axxxxxx   my-subnet                 available   10.240.128.0/18   16373/16384   husker-sloping-bee-resize                              my-gateway                                 my-vpc              us-south-3   kubeflow   
    

    If the above list contains the subnet corresponding to your VPC, that can be used to deploy your cluster - make sure you note it’s ID.

    b) To create a new subnet:

    • List address prefixes and note the CIDR block corresponding to a Zone; in the below example, for Zone: us-south-3 the CIDR block is : 10.240.128.0/18.
    ibmcloud is vpc-address-prefixes $VPC_ID
    

    Example output:

    Listing address prefixes of vpc r006-hidden-68cc-4d40-xxxx-4319fa3fxxxx under account IBM as user new@user-email.com...
    ID                                          Name                                CIDR block        Zone         Has subnets   Is default   Created   
    r006-xxxxxxxx-4002-46d2-8a4f-f69e7ba3xxxx   rising-rectified-much-brew          10.240.0.0/18     us-south-1   false         true         2021-03-05T14:58:39+05:30   
    r006-xxxxxxxx-dca9-4321-bb6c-960c4424xxxx   retrial-reversal-pelican-cavalier   10.240.64.0/18    us-south-2   false         true         2021-03-05T14:58:39+05:30   
    r006-xxxxxxxx-7352-4a46-bfb1-fcbac6cbxxxx   subfloor-certainly-herbal-ajar      10.240.128.0/18   us-south-3   false         true         2021-03-05T14:58:39+05:30  
    
    • Now create a subnet as follows:
    ibmcloud is subnet-create my-subnet $VPC_ID $CLUSTER_ZONE --ipv4-cidr-block "10.240.128.0/18"
    

    Example output:

    Creating subnet my-subnet in resource group kubeflow under account IBM as user new@user-email.com...
                             
    ID                  0737-27299d09-1d95-4a9d-a491-a6949axxxxxx   
    Name                my-subnet
    
    • Make sure you export the subnet IDs follows:
    export SUBNET_ID=0737-27299d09-1d95-4a9d-a491-a6949axxxxxx
    
  5. Create a vpc-gen2 based Kubernetes cluster:

    ibmcloud ks cluster create vpc-gen2 \
    --name $CLUSTER_NAME \
    --zone $CLUSTER_ZONE \
    --version ${KUBERNETES_VERSION} \
    --flavor ${WORKER_NODE_FLAVOR} \
    --vpc-id ${VPC_ID} \
    --subnet-id ${SUBNET_ID} \
    --workers 2
    
  6. Attach a public gateway

    This step is mandatory for Kubeflow deployment to succeed, because pods need public internet access to download images.

    • First, check if your cluster is already assigned a public gateway:
    ibmcloud is pubgws
    

    Example output:

    Listing public gateways for generation 2 compute in all resource groups and region ...
    ID                                          Name                                       Status      Floating IP      VPC                 Zone         Resource group   
    r006-xxxxxxxx-5731-4ffe-bc51-1d9e5fxxxxxx   my-gateway                                 available   xxx.xxx.xxx.xxx       my-vpc              us-south-3   default   
      
    

    In the above run, the gateway is already attached for the vpc: my-vpc. In case no gateway is attached, proceed with the rest of the setup.

    • Next, attach a public gateway by running the following command:
    ibmcloud is public-gateway-create my-gateway $VPC_ID $CLUSTER_ZONE
    

    Example output:

    ID: r006-xxxxxxxx-5731-4ffe-bc51-1d9e5fxxxxxx
    

    Save the above generated gateway ID as follows:

    export GATEWAY_ID="r006-xxxxxxxx-5731-4ffe-bc51-1d9e5fxxxxxx"
    
    • Finally, attach the public gateway to the subnet:
    ibmcloud is subnet-update $SUBNET_ID --public-gateway-id $GATEWAY_ID
    

    Example output:

    Updating subnet 0737-27299d09-1d95-4a9d-a491-a6949axxxxxx under account IBM as user new@user-email.com...
                             
    ID                  0737-27299d09-1d95-4a9d-a491-a6949axxxxxx   
    Name                my-subnet   
    ...
    

Verifying the cluster

To use the created cluster, switch the Kubernetes context to point to the cluster:

ibmcloud ks cluster config --cluster ${CLUSTER_NAME}

Make sure all worker nodes are up with the command below:

kubectl get nodes

and verify that 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}