Ephemeral Containers

    This page provides an overview of ephemeral containers: a special type of container that runs temporarily in an existing Pod to accomplish user-initiated actions such as troubleshooting. You use ephemeral containers to inspect services rather than to build applications.

    Pods are the fundamental building block of Kubernetes applications. Since Pods are intended to be disposable and replaceable, you cannot add a container to a Pod once it has been created. Instead, you usually delete and replace Pods in a controlled fashion using .

    Ephemeral containers differ from other containers in that they lack guarantees for resources or execution, and they will never be automatically restarted, so they are not appropriate for building applications. Ephemeral containers are described using the same ContainerSpec as regular containers, but many fields are incompatible and disallowed for ephemeral containers.

    • Ephemeral containers may not have ports, so fields such as ports, , readinessProbe are disallowed.
    • For a complete list of allowed fields, see the .

    Ephemeral containers are created using a special handler in the API rather than by adding them directly to pod.spec, so it’s not possible to add an ephemeral container using kubectl edit.

    Note: Ephemeral containers are not supported by static pods.

    Ephemeral containers are useful for interactive troubleshooting when is insufficient because a container has crashed or a container image doesn’t include debugging utilities.

    When using ephemeral containers, it’s helpful to enable process namespace sharing so you can view processes in other containers.