= Mounting the configuration file directly into the appropriate pod and container using the .spec.containers.configMounts key is not a valid way to provide a configuration file to a container at runtime. The .spec.containers.configMounts key does not exist in the Kubernetes API1. The correct way to provide a configuration file to a container at runtime is to use a ConfigMap2. A ConfigMap is a Kubernetes object that stores configuration data as key-value pairs. You can create a ConfigMap from a file, and then mount the ConfigMap as a volume into the pod and container. The configuration file will be available as a file in the specified mount path3. Alternatively, you can also use environment variables to pass configuration data to a container from a ConfigMap4. References:

PodSpec v1 core

Configure a Pod to Use a ConfigMap

Populate a Volume with data stored in a ConfigMap

Define Container Environment Variables Using ConfigMap Data