Which Kubernetes object is designed to run a single instance of a container?

The Pod is the fundamental building block of Kubernetes and is specifically designed to run one or more containers as a single unit. When you want to execute a single instance of a container, you would create a Pod and specify the container image and any required configurations, such as environment variables or volume mounts.

Kubernetes manages Pods to ensure that they run and are healthy. Each Pod is assigned a unique IP address and can contain one or more closely related containers that share storage and network resources. This design allows containers within the same Pod to communicate easily and share data.

While other Kubernetes objects, such as ReplicaSet, Deployment, and StatefulSet, can manage the lifecycle of Pods (such as scaling and updates), their primary role is not to run a single instance of a container. ReplicaSets are used to manage multiple copies of Pods, Deployments facilitate updates and manage the state of applications by controlling a set of identical Pods, and StatefulSets manage the deployment of stateful applications, ensuring that each Pod has a unique and persistent identity. Thus, when referring specifically to running a single instance of a container, the correct object in Kubernetes is the Pod.