Using Compute Profiles (vSphere)

This topic describes how to use compute profiles using the VMware Tanzu Kubernetes Grid Integrated Edition (TKGI) Command Line Interface (TKGI CLI).

Overview

A compute profile enables TKGI cluster managers to configure TKGI-provisioned Kubernetes clusters with custom settings:

• TKGI cluster administrators can create compute profiles with custom cluster resource parameters and settings. Cluster administrators must have pks.clusters.admin accounts.
• TKGI cluster managers can configure new and existing clusters with a compute profile to override the cluster configuration settings defined by a plan. Cluster managers must have pks.cluster.manage accounts.

TKGI supports creating and managing compute profiles for Linux- and Windows-based Kubernetes clusters on vSphere with NSX-T networking and for Linux-based Kubernetes clusters on vSphere without NSX-T networking.

For an overview of how compute profile are created, see How Compute Profiles are Created below.

For information about using compute profiles, see:

• List Compute Profiles
• Create a Cluster with a Compute Profile
• Assign a Compute Profile to an Existing Cluster
• Resize a Cluster that Has an Existing Compute Profile

How Compute Profiles are Created

TKGI cluster administrators can create and delete compute profiles. For information on how cluster administrators create and delete compute profiles, see Creating and Managing Compute Profiles with the CLI (vSphere).

List Compute Profiles

To list available compute profiles, run the following command:

tkgi compute-profiles

For example:

$ tkgi compute-profiles  
  
Name                              Description  
custom-nodes-compute-profile      custom-nodes-compute-profile  
custom-node-pools-compute-profile custom-node-pools-compute-profile  
Dc-east-single-node-pool          A profile for the east datacenter with a single node pool  
dc-east-mixed                     A profile for the east datacenter with heterogeneous workers  

Create a Cluster with a Compute Profile

You can assign a compute profile to a TKGI-provisioned Kubernetes cluster at the time of cluster creation.

To create a cluster with a compute profile:

1. Review the following strict validation rules for the tkgi create-cluster --compute-profile command:

   • If an optional compute profile field is unspecified at the time of cluster creation, the value of that field is set to the value of the corresponding field from the plan.
   • tkgi create-cluster --compute-profile ignores the --num-nodes argument.
   • The node pool name passed to --node-pool-instances must match the name property of a node pool in the compute profile.

2. To create the cluster, run the following command:

   tkgi create-cluster CLUSTER-NAME --external-hostname HOSTNAME --plan PLAN-NAME --compute-profile COMPUTE-PROFILE-NAME --node-pool-instances "NODE-POOL-NAME:INSTANCES"
   

   Where:

   • CLUSTER-NAME is a unique name for your cluster.
     

     Note: Use only lowercase characters when naming your cluster if you manage your clusters with Tanzu Mission Control (TMC). Clusters with names that include an uppercase character cannot be attached to TMC.

   • HOSTNAME is your external hostname used for accessing the Kubernetes API.
   • PLAN-NAME is the name of the TKGI plan you want to use for your cluster.
   • COMPUTE-PROFILE-NAME is the name of the compute profile you want to use for your cluster.
   • (Optional) --node-pool-instances "NODE-POOL-NAME:INSTANCES" overrides a compute profile’s configured node pool worker node instance count:
     • NODE-POOL-NAME is the name of the node pool to configure. The node pool name must match the name property of a node pool in the compute profile.
     • INSTANCES is the number of worker node instances to create for the node pool.

   For example:

   tkgi create-cluster custom-node-pools -e test.tkgi.shep.api.com --compute-profile custom-node-pools-compute-profile -p "small" --node-pool-instances "tiny-1:3"
   
   TKGI Version:             1.9.0-build.11  
   Name:                     test  
   K8s Version:              1.18.5  
   Plan Name:                small  
   UUID:                     <UUID of deployment>1  
   Last Action:              CREATE  
   Last Action State:        in progress  
   Last Action Description:  Creating cluster  
   Kubernetes Master Host:   test.tkgi.shep.api.com  
   Kubernetes Master Port:   8443  
   Worker Nodes:             4  
   Kubernetes Master IP(s):  In Progress  
   Network Profile Name:  
   Kubernetes Profile Name:  
   Compute Profile Name:     custom-node-pools-compute-profile  
   Tags:  
   

Assign a Compute Profile to an Existing Cluster

TKGI supports changing the compute profile for an already created cluster.

You can use this procedure to:

• Assign a compute profile to a cluster that does not have one.
• Change a cluster’s existing profile to a new one.

To assign a compute profile to an existing cluster, complete the following:

1. Compute Profile Update and Resize Validation.
2. Assign a Compute Profile.

Compute Profile Update and Resize Validation

The following are not supported when modifying an existing compute profile:

• Your modification cannot change a node pool’s name property.
• Your modification cannot simultaneously add a new node pool and delete an existing node pool.

Before assigning a compute profile to an existing cluster:

1. Review the following strict validation rules for the tkgi update-cluster --compute-profile command:

   • You cannot use a compute profile to change the Availability Zones of an existing cluster.
   • You cannot use a compute profile to change the number of control plane nodes for an existing cluster.
   • If an optional compute profile field is unspecified at the time of cluster update, the value of that field is set to the value of the corresponding field from the plan.
   • tkgi update-cluster --compute-profile ignores the --num-nodes argument.
   • Values passed to --node-pool-instances must match a name property of the node pools in the compute profile.
   • You cannot update a compute profile that was applied to a cluster in TKGI 1.8 or earlier.

2. Review the following precautions and warnings:

   Warning: Do not scale out or scale in existing control plane nodes by reconfiguring the TKGI tile. Reducing a cluster’s number of control plane nodes might remove a control plane node and cause the cluster to become inactive.

   Warning: If cluster update fails while applying a new compute profile with revised node pool names, do not reapply the previous compute profile: the cluster’s worker nodes will be deleted. If you encounter this scenario, fix the new compute profile configuration without modifying the node pool names, and retry your cluster update. For more information, see tkgi update-cluster compute profile failure in the VMware Tanzu Knowledge Base.

   Note: Compute profiles do not support moving a cluster’s nodes to different Availability Zones.

3. Resolve any conditions matching the listed concerns, precautions or warnings.

Assign a Compute Profile

To assign a compute profile to an existing cluster:

1. Select the compute profile to apply to the cluster:

   • Choose an existing compute profile: See List Compute Profiles.
   • Create a new compute profile: Have a TKGI cluster administrator define and create a new compute profile as described in Create a Compute Profile in Creating and Managing Compute Profiles with the CLI (vSphere).
     • The name of the new compute profile must be unique and different from the previously assigned compute profile.

2. If you are updating a cluster that uses a public cloud CSI driver, see Limitations on Using a Public Cloud CSI Driver in Release Notes for additional requirements.

3. Run the following command to update the cluster with the new compute profile:

   tkgi update-cluster CLUSTER-NAME --compute-profile NEW-COMPUTE-PROFILE-NAME --node-pool-instances "NODE-POOL-NAME:INSTANCES"
   

   Where:

   • CLUSTER-NAME is the name of the existing Kubernetes cluster.
   • NEW-COMPUTE-PROFILE-NAME is the name of the new compute profile you want to apply to the cluster.
   • (Optional) --node-pool-instances "NODE-POOL-NAME:INSTANCES" overrides a compute profile’s configured node pool worker node instance count:
     • NODE-POOL-NAME is the name of the node pool to configure. The node pool name must match the name property of a node pool in the compute profile.
     • INSTANCES is the number of worker node instances to create for the node pool.

   For example:

   tkgi update-cluster test --compute-profile new-compute-profile  
   
   Update summary for cluster test:  
   Compute Profile Name: new-compute-profile  
   Are you sure you want to continue? (y/n): y  
   Use 'tkgi cluster test' to monitor the state of your cluster  
   

4. (Optional) To bypass compute profile validation, include the --enforce-compute-profile-update parameter in your tkgi update-cluster command line. VMware recommends that you always allow validation when updating clusters in production environments.

   For example:

   tkgi update-cluster test --compute-profile bad-compute-profile  --enforce-compute-profile-update
   
   Update summary for cluster test:  
   Compute Profile Name: bad-compute-profile  
   Are you sure you want to continue? (y/n): y  
   Use 'tkgi cluster test' to monitor the state of your cluster  
   

WARNING: Updating a cluster with a compute profile is not supported on a TKGI cluster that has not been upgraded to the current TKGI version. For more information, see Tasks Supported Following a TKGI Control Plane Upgrade in About Tanzu Kubernetes Grid Integrated Edition Upgrades.

Resize a Cluster that Has an Existing Compute Profile

TKGI supports using the CLI to resize a cluster already created or assigned with a compute profile, without having to create a new compute profile.

To resize a cluster:

1. If you are updating a cluster that uses a public cloud CSI driver, see Limitations on Using a Public Cloud CSI Driver in Release Notes for additional requirements.

2. Run the tkgi update-cluster command with the --node-pool-instances option:

   • Pass in a comma-separated list that associates node pools defined in the compute profile with new instance counts. This changes the number of instances from each node pool.
   • The node pools must already be defined in the cluster’s compute profile.

   For example, to resize a cluster custom-node-pools-cluster to use three nodes from the node pool named tiny-1 and seven from the pool named medium-2:

   tkgi update-cluster custom-node-pools-cluster  --node-pool-instances "tiny-1:3,medium-2:7"