DCA Dumps With Exact Questions and Answers

The set of commands docker container inspect and docker port can identify the published port(s) for a container. The docker container inspect command returns low-level information about a container, including its network settings and port bindings1. The docker port command lists port mappings or a specific mapping for the container2. Both commands can show which host port is mapped to which container port, and the protocol used. For example, docker container inspect -f '{{.NetworkSettings.Ports}}' container_name will show the port bindings for the container_name3. Similarly, docker port container_name will show the port mappings for the container_name. References:

• docker container inspect
• docker port
• How to Expose and Publish Ports in Docker
• [How to obtain the published ports from within a docker container?]

The provided Kubernetes NetworkPolicy YAML configuration indicates that the policy applies to pods with the label tier: backend in the default namespace1. The ingress rule allows traffic from pods with the label tier: api1. Therefore, a request issued from a pod bearing only the tier: frontend label to a pod bearing the tier: backend label will be blocked by this networkPolicy1. This is because the networkPolicy does not have a rule allowing ingress from pods with the tier: frontend label1. For more information on Kubernetes NetworkPolicies, you can refer to the Kubernetes Documentation on Network Policies.

= The command ‘docker run --volume /data:/mydata:ro ubuntu’ will mount the host’s ‘/data’ directory to the ubuntu container in read-only mode. The --volume or -v option allows you to mount a host directory or a file to a container as a volume1. The syntax for this option is:

-v|--volume=[host-src:]container-dest[:]

The host-src can be an absolute path or a name value. The container-dest must be an absolute path. The options can be a comma-separated list of mount options, such as ro for read-only, rw for read-write, z or Z for SELinux labels, etc1. In this case, the host-src is /data, the container-dest is /mydata, and the option is ro, which means the container can only read the data from the volume, but not write to it2. This can be useful for sharing configuration files or other data that should not be modified by the container3. References:

• Use volumes | Docker Documentation
• Docker run reference | Docker Documentation
• Docker - Volumes - Tutorialspoint