Create and manage cluster

Create cluster

A cluster is the fundamental resource of Kubernetes Engine, where all Kubernetes objects, including containerized applications, are run. You can create clusters via the console, with API support for cluster creation coming soon. Here's how to create a cluster in Kubernetes Engine.

info

• In the kr-central-2 region, which supports Multi-AZ, you can improve availability by operating clusters and nodes across multiple availability zones (AZs) within the region.
• Before creating a cluster, ensure that a VPC and subnet have already been configured. If they are not yet set up, refer to Create and manage VPC.

Create cluster in the console

You can create a cluster in the KakaoCloud console.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine.

2. Click the [Getting started] button to start Kubernetes Engine.

   • Once the service is initiated, a service agent will be created to access the Kubernetes Engine resources.

3. In the Cluster menu, click the [Create cluster] button.

4. In Create cluster, enter the required information and click [Create].

   

   Section	Description
   Basic settings	• Set basic information for the cluster. - Cluster name: Enter the name of the cluster. - Description (optional): Write a description up to 60 characters. - Kubernetes version: Select the version to use in the cluster.   ᄂ Refer to Supported Kubernetes versions for details.
   Network settings	• Configure the cluster's network settings. - VPC: Select a VPC shared with the project to deploy the cluster. - Subnet: Select a subnet from the project for cluster deployment.   ᄂ Select subnets for nodes when creating a node pool.   ᄂ For the kr-central-2 region, you can select multiple subnets in different availability zones to improve availability.   ᄂ At least one subnet from each AZ in kr-central-2 must be selected for a Multi-AZ cluster. • Cluster endpoint access: Choose public or private access.   ᄂ Public endpoint: Allows cluster endpoint access from external internet.   ᄂ Private endpoint: Restricts cluster endpoint access to the internal VPC network.
   CNI	• Choose between Calico and Cilium as the CNI plugin. - Service IP CIDR block (optional): Set the IP for service objects. - Pod IP CIDR block (optional): Set the IP for pods. ⚠️ Warning Service IP and Pod IP cannot be changed after cluster creation.

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Nodes in private subnets cannot communicate with the internet.
For private subnet nodes to communicate with external CRs, NAT is required. You can use a NAT instance. Refer to Appendix. NAT instance for more details.

caution

Allowed conditions for CNI service IP and pod IP are as follows:

• Must be in CIDR format and fall within the private network ranges defined in RFC 1918 for IPv4.
• The minimum size for service IPs is /28, and the maximum is /12.
• The minimum size for pod IPs is /24, and the maximum is /16.
• Service IPs and pod IPs must not overlap.
• Service IPs and pod IPs must not overlap with the VPC set as the cluster network.
• The reserved IP range 198.18.0.0/16 used internally by Kubernetes Engine must not overlap.
• Only IPv4 is supported for service IPs and pod IPs.

Cluster endpoint

• Depending on the cluster endpoint configuration, the API server endpoint URL is provided.

  Cluster endpoint option	Description
  Public cluster endpoint	Provides an API server endpoint accessible from the external internet. The API server endpoint is a public IP address.
  Private cluster endpoint	Provides an API server endpoint restricted to the VPC internal network. The API server endpoint is a private IP address within the VPC. External internet access is not possible.

Manage cluster

Here’s how to manage a cluster in the Kubernetes Engine service.

View cluster list

You can view the list of currently created clusters.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine.

2. In the Cluster menu, view the current clusters.

   Field	Description
   Name	Cluster name
   ID	Unique cluster ID
   Status	Cluster status: - Provisioned: Cluster provisioning complete - Pending: Cluster provisioning pending - Provisioning: Cluster provisioning in progress - Deleting: Cluster deletion in progress - Failed: Failed, requires user intervention
   Kubernetes version	Version information for the cluster's Kubernetes installation
   Creator	Creator ID for the cluster
   Created at	Date the cluster was created
   [More] icon	- kubeconfig file: Download kubeconfig for kubectl control - Set scale-in: Set node pool auto-scaling conditions - Modify cluster: Modify the cluster name or description - Delete cluster: Delete the cluster

Configure scale-in for clusters

Configure the auto downscaling conditions for the node pools of clusters with auto-scaling enabled. This condition automatically reduces the number of nodes when node resource usage (CPU/Memory) remains below a certain threshold. Auto downscaling conditions can be set cluster-wide, applying to all node pools within the cluster.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine.

2. In the Cluster menu, click the [More] icon for the target cluster and select Set scale-in.

3. In the Set scale-in popup, enter the required information and click [Save].

   Auto downscaling settings popup

   Field	Description
   Auto scale-in of node pools within the cluster	Enable or disable auto downscaling for all node pools using the auto-scaling feature within the cluster. - Default: Enabled
   Auto scale-in threshold conditions	Set the node resource usage threshold (CPU/Memory) for auto downscaling. - Range: 1–100 - Default: 50%
   Threshold duration	Duration (in minutes) that node resource usage must remain below the threshold before downscaling occurs. - Range: 1–1440 minutes - Default: 10 minutes
   Cooldown period after scale-out	Exclude nodes from downscaling for a set period after they have been scaled up. - Range: 10–1440 minutes - Default: 10 minutes

Modify cluster

Modify or view the name, creation date, or description of a cluster.

1. In the KakaoCloud Console, select the Kubernetes Engine menu.

2. In the Cluster menu, click the [More] icon for the desired cluster and select Modify cluster.

3. In the Modify cluster popup, view or update the details. If needed, update the information and click [Apply].

   Field	Description
   Cluster name	Current name of the cluster
   Cluster creation date	The date the cluster was created
   Description (optional)	Description entered during cluster creation, up to 60 characters.

Delete cluster

You can delete clusters that are no longer in use.

caution

• When deleting a cluster, resources automatically created during cluster creation will also be deleted. For details, refer to Automatically created resources during cluster/node pool creation.
• Security groups automatically created for nodes will not be deleted if additional instances were connected to them.

1. In the KakaoCloud Console, select the Kubernetes Engine menu.
2. In the Cluster menu, click the [More] icon for the clusterto delete and select Delete cluster.
3. In the Delete cluster popup, enter the required information and click [Delete].

Update cluster

When a new Kubernetes version is available in Kubernetes Engine, you can update the control plane of a cluster to the latest version. Upon starting an update, a new control plane with the latest version is created, replacing the existing one. Here's how to update a cluster in the Kubernetes Engine service.

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For more details on the supported Kubernetes versions in Kubernetes Engine, refer to Supported versions.

Before starting update

Before starting the update, ensure that the following conditions are met. If not, the update will not proceed. Check the Changelog from the open-source community to assess how changes in the Kubernetes version may affect your applications.

Update conditions

Condition	Description
Cluster status	Provisioned status - If in another status, the update button will not be shown.
Node pool status	All node pools must be in the Running state - The update button will not appear otherwise.
Node pool version	All node pools must match the cluster version. If they differ by more than one version, the update button will not appear.

Update procedures

If the cluster can use the latest version and meets all update conditions, you can proceed with the update.

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Kubernetes versions are updated incrementally, and only one version can be updated at a time.
To update multiple versions, perform each update sequentially.

caution

Once the update starts, it cannot be canceled, and you cannot roll back to the previous version.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine menu.

2. In the Cluster menu, click the Update button in the Kubernetes version column for the cluster you want to update.

3. In the popup, review the Update version and click [Update].

4. Once the cluster update starts, the cluster status will change to Updating. After the update completes, the status will change to Provisioned. While updating, you cannot add new node pools or modify existing ones.

Considerations after updating

After updating the cluster, when creating a new node pool, the latest node version matching the cluster version will be applied. Existing node pools cannot be modified and must be updated. For more details on node pool updates, refer to Update nodes.

What to check if update fails

If the update fails, the cluster status will change to Failed. If this happens, contact Helpdesk > Technical Support.

1. In the KakaoCloud Console, select Helpdesk from the upper-right corner.
2. In the Q&A tab, click [Ask a question] in the upper-right corner.
3. Click [Technical Support].
4. In Ask a question, enter the information and click [Submit].

View cluster details

You can check detailed information about the cluster, node pools, and nodes.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine menu.

2. In the Cluster menu, select the cluster to view details.

3. In the cluster details page, review the information.

   Field	Description
   Cluster status	The status of the selected cluster
   Kubernetes version	The current Kubernetes version in use
   Creator	The ID of the cluster creator
   Created at	The date the cluster was created

View cluster details

Check details like cluster ID, total vCPUs, and network information.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine menu.

2. In the Cluster menu, select the cluster to view details.

3. In the Details tab, review the information.

   Field	Description
   ID	The unique ID of the cluster
   API server endpoint	The endpoint for calling the cluster API
   Total vCPUs	The total number of vCPUs in worker nodes within the cluster
   Total memory	The total memory of worker nodes in the cluster
   VPC	The VPC where the cluster is deployed
   Subnets	The subnets where the cluster is deployed - In the kr-central-2 region, if multiple subnets in different AZs are selected for improved availability, all applicable subnets are displayed.
   Security groups	The security groups applied to worker nodes in the cluster

View node pool information

Check information about node pools within the cluster and the nodes in those pools.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine menu.

2. In the Cluster menu, select the cluster to view node pool information.

3. Click the Node pool tab to review the information.

   Field	Description
   Node pool	Name and description of the node pool - Click on the node pool name to view the detailed page
   Node pool status	Node pool status - Running: Node pool running (regardless of node status) - Running (Scheduling Disabled): All nodes in the node pool have scheduling disabled - ScalingUp: Nodes are being added - ScalingDown: Nodes are being removed - Deleting: Node pool deletion in progress - Failed: Failed, requires user intervention
   Kubernetes version	Kubernetes version used by the node pool
   Instance type	Type of instances used by nodes in the node pool
   Node pool type	Type of instances running the nodes
   Volume size	Volume size of the instances used by the node pool
   Number of nodes	Number of nodes in the node pool
   Availability zone	Availability zone information for the subnets used by the node pool

View node information

Check details about all nodes within the cluster.

1. Navigate to the KakaoCloud Console > Container Pack > Kubernetes Engine menu.

2. In the Cluster menu, select the cluster to view node information.

3. Click the Node tab to review the information.

   Field	Description
   Node	Name and description of the node - Click the node name to view its details page
   Node status	Node status - Running: Node is ready and running - Running (Scheduling Disabled): Node scheduling is blocked (unrelated to pods already assigned and running) - Provisioned: Node provisioning complete - Deleted: Node deletion complete - Pending: Node provisioning pending - Provisioning: Node provisioning in progress - Deleting: Node deletion in progress - Failed: Failed, requires user intervention
   Node pool	Node pool information for the node - Click the node pool to view its details page
   Private IP	Private IP information of the node
   Availability zone	Availability zone information for the subnet where the node is running
   Pod scheduling	Allowed: New pods can be assigned to the node Blocked: New pod assignments are blocked
   Uptime	Time elapsed since the node was requested, not the creation date