A .yaml file is a common file type for defining the configuration and deployment of application containers in a cloud environment. YAML stands for YAML Ain’t Markup Language, and it is a human-readable data serialization language that uses indentation and keywords to represent the structure and values of the data1. A .yaml file can specify the properties of the container, such as the image, ports, environment variables, volumes, resources, and scaling rules. For example, to modify the replication factor of an automated application container from 3 to 5, the systems administrator can edit the .yaml file on the master controller and change the value of the replicas field under the spec section2. For example:
apiVersion: apps/v1 kind: Deployment metadata: name: my-app spec: replicas: 5 # change this value from 3 to 5 selector: matchLabels: app: my-app template: metadata: labels: app: my-app spec: containers: - name: my-app image: my-app-image ports: - containerPort: 80
A .txt file is a plain text file that can store any kind of text data, but it is not a standard format for defining container configurations. A .conf file is a configuration file that can store settings and parameters for various applications or services, but it is not commonly used for container deployments. A .etcd file is not a valid file type, but etcd is a distributed key-value store that provides a reliable way to store data across a cluster of machines3. Etcd is often used by Kubernetes, a popular platform for managing containerized applications, to store and synchronize the cluster state. However, etcd does not store the configuration files of the containers, but rather the runtime data of the cluster. Therefore, none of these options are correct.
