Certified Kubernetes Application Developer (CKAD) Practice Test

Specifying environment variables for containers in a Pod is primarily done within the container specification in the Pod definition. This is typically outlined in the YAML or JSON configuration file used to create the Pod. In the container spec, you can use the `env` field to declare environment variables directly, allowing you to define key-value pairs that the container can access when it runs.

For example, you might specify environment variables like this in your Pod definition:

```yaml

apiVersion: v1

kind: Pod

metadata:

name: example-pod

spec:

containers:

- name: example-container

image: example-image

env:

- name: ENV_VAR_NAME

value: "some-value"

```

This flexibility allows you to configure your application dynamically based on the environment it is running in. The other options, while they might involve aspects of configuration management, do not directly address how to define environment variables within the context of a Pod's lifecycle in Kubernetes.