In Kubernetes, a pod represents the smallest deployable unit that can be scheduled and managed by the Kubernetes control plane. A pod consists of one or more containers that share the same network namespace and can communicate with each other using local hostnames and ports.
In the lifecycle of a Kubernetes pod, there are several stages that it goes through. These stages include:
Pending: A pod is in the Pending state when it has been created, but its containers are not yet running. During this stage, the Kubernetes control plane is scheduling the pod to run on a node that has the necessary resources to support it.
Running: A pod is in the Running state when all of its containers have been successfully created and are running. At this stage, the pod is actively serving requests and running as intended.
Succeeded: A pod is in the Succeeded state when all of its containers have completed their tasks successfully and terminated. This is typically used for batch jobs or other one-time processes that have a defined start and end.
Failed: A pod is in the Failed state when one or more of its containers have failed to start or have exited with an error. This could be due to issues with the container image, configuration, or dependencies.
Unknown: A pod is in the Unknown state when its state cannot be determined by the Kubernetes control plane. This could happen if the control plane is unable to communicate with the pod, or if there is an issue with the pod's configuration.
It's important to note that pods are considered ephemeral and can be deleted and recreated by the Kubernetes control plane as needed. To maintain the state of your application, it's recommended to use Kubernetes deployments, which provide a higher level of abstraction and can manage the lifecycle of your pods automatically.
