A replica is the number of instances of the Pod that will be created and maintained by Kubernetes across the Nodes in the cluster. If you want to scale your application horizontally (to provide more overall resources by running more instances), you define replicas. The following diagram shows a Pod with two containers and how Pods sharing the network.Įach Pod is meant to run a single instance of a your application.
There will be a separate article describing multiple containers in this blog. In this case, one container could sends files when another container acts as the web server. In another example, you may want for an application of two containers to share a volume. For example, you may want a web server Pod to contain an nginx container and a Ruby container. You may want to have multiple containers share resources. Typically you will deploy a single container in a Pod. There are two ways that Pods work in a cluster:
What is kubernetes pods manual#
Kubernetes performs actions to make Pods self-healing without manual intervention. Containers share resources in a secure way in Pods. Pods gives Kubernetes a way to orchestrate containers deployed at large scale. Pods give Kubernetes a way to scale, configure, and apply patches to containers. You can think of a Pod as a wrapper around containers that allow Kubernetes to scale and allow containers to share resources (like storage and networking.) Kubernetes manages Pods rather than managing the containers directly.
What is kubernetes pods how to#
In this article, you learn about how Pods work, how you can have multiple containers in a Pod, the lifecycle of a Pod, how Kubernetes handles networking with a Pod, and how to define a Pod using a PodTemplate in a Deployment, Job, or other Kubernetes resource. But you should know that you define Windows or Linux when you create the cluster. So the command to manage Pods running Windows are the same as those running Linux. In short, Pods enable you to manage several tightly coupled application containers as a single unit. Docker is the most commonly known runtime, but it can be other types. For example, Pods provide shared storage/network resources, and a specification for how to run the containers. Containers are grouped into Pods so Kubernetes can provide services that are not supported in containers. Pods are the smallest deployable units of computing that you can create and manage in Kubernetes.Ī Pod contains one or more containers.