Relationship between service resources
Kubernetes is an environment for managing containerized applications. Kubernetes offers ways to run clusters that can automate tasks like deploying, scaling, and managing applications in containers.
The main entity used in the service is a cluster Kubernetes.
A Kubernetes cluster consists of a master and one or more node groups. The master is responsible for managing a Kubernetes cluster. Containerized user applications are run on nodes.
The service fully controls the master and monitors the status and health of a node group. The user can manage nodes directly and configure a Kubernetes cluster through the Yandex.Cloud management console and the Managed Service for Kubernetes CLI and API.
Kubernetes node groups require internet access to download images and components. Internet access can be provided in the following ways:
When working with a Kubernetes cluster in the Yandex.Cloud infrastructure, the following resources are used:
|Subnet||2||Kubernetes reserves IP address ranges to be used for pods and services.|
|Public IP||N||N includes: - A single public IP address for the NAT instance. - A public IP address assigned to each node in the group if you use the one-to-one NAT technology.|
Masters are components that manage Kubernetes clusters.
They run Kubernetes control processes that include the Kubernetes API server, scheduler, and main resource controllers. The master lifecycle is managed by the service when creating or deleting a Kubernetes cluster. The master is responsible for global solutions that are run on all Kubernetes cluster nodes. These include scheduling workloads (such as containerized applications), managing the lifecycle of workloads, and scaling.
There are two types of masters that differ by their location in availability zones:
Zonal: A master created in a subnet in one availability zone.
Regional: A master created and distributed in three subnets in each availability zone. If a zone becomes unavailable, the regional master remains functional.
The internal IP address of a regional master is only available within a single Yandex Virtual Private Cloud cloud network.
A node group is a group of VMs with the same configuration in a Kubernetes cluster that is running the user's containers.
When you create a group of nodes, you can configure the following VM parameters:
- Type of VM.
- Type and number of cores (vCPU).
- Amount of memory (RAM) and disk space.
You can create groups with different configurations in a cluster and place them in different availability zones.
Connecting to group nodes
You can connect to nodes in a group via SSH. Learn more in Connecting to a node over SSH.