Docker DCA Exam Dumps

Label constraints can be used to schedule containers to meet the security policy requirements.Label constraints allow you to specify which nodes a service can run on based on the labels assigned to the nodes1. For example, you can label the nodes that are intended for development withenv=devand the nodes that are intended for production withenv=prod. Then, you can use the--constraintflag when creating a service to restrict it to run only on nodes with a certain label value.For example,docker service create --name dev-app --constraint 'node.labels.env == dev' ...will create a service that runs only on development nodes2.Similarly,docker service create --name prod-app --constraint 'node.labels.env == prod' ...will create a service that runsonly on production nodes3. This way, you can ensure that development and production containers are running on separate nodes in a given Swarm cluster.Reference:

Add labels to swarm nodes

Using placement constraints with Docker Swarm

Multiple label placement constraints in docker swarm

The statement is not entirely correct.In Kubernetes, a service of typeClusterIProutes traffic sent to its IP address to the pods selected by its label selector1.However, the port to which the traffic is routed in the pod is determined by thetargetPortspecified in the service definition1.IftargetPortis not specified, it defaults to being the same as theportfield1. In the providedYAML snippet, there is notargetPortspecified for port 80, so we cannot confirm that the traffic will be routed to port 8080 in the pod.Therefore, without additional information about the pod configuration, we cannot verify the provided solution statement1.

= The role of Control Groups (cgroups) when used with a Docker container isnotrole-based access control to clustered resources.Cgroups are a feature of the Linux kernelthat allow you tolimit, manage, and isolate resource usageof collections of processes running on a system1.Resources are CPU time, system memory, network bandwidth, or combinations of these resources, and so on2.Cgroups allow Docker Engine to share available hardware resources to containers and optionally enforce limits and constraints3.Cgroups can help avoid ''noisy neighbor'' issues and improve the performance and security of containers4.Role-based access control (RBAC) is a different concept that refers to controlling access to resources based on the roles of individual users within an organization5.

: :Lab: Control Groups (cgroups) | dockerlabs:Container security fundamentals part 4: Cgroups | Datadog Security Labs:Docker Namespace Vs Cgroup. Namespace and Cgroup | by MrDevSecOps - Medium:Role-based access control - Wikipedia:Control groups (cgroups) - Learn Docker - Fundamentals of Docker 18.x ...

= Docker will block the commanddocker image inspect myorg/myimage: 1.0if the image tag is unsigned and the environment variable DOCKER_CONTENT_TRUST is set to 1.This is because Docker Content Trust (DCT) enables the verification of the integrity and publisher of Docker images using digital signatures1.When DCT is enabled, Docker will only pull, run, or inspect images that have a valid signature2.If the image tag is not signed, Docker will reject the command and display an error message, such asNo valid trust data for 1.03. To inspect an unsigned image, you need to either disable DCT by setting DOCKER_CONTENT_TRUST to 0, or use the--disable-content-trustflag with the command.Reference:

Content trust in Docker | Docker Docs

Enable and disable content trust in Docker | Docker Docs

Docker Content Trust: What It Is and How It Secures Container Images

[docker image inspect | Docker Docs]