Docker Updated DCA Exam Questions and Answers by reign

Docker allows the use of insecure registries through a specific configuration in the Docker daemon.By listing the insecure registries in the ‘daemon.json’ configuration file under the ‘insecure-registries’ key, Docker can interact with these registries even without a trusted TLS certificate1.This is particularly useful when setting up a private Docker registry1.However, it’s important to note that this configuration bypasses the security provided by TLS, and should be used with caution1.

= The command docker service create --network --secure will not ensure that overlay traffic between service tasks is encrypted. This is because the --secure option is not a valid option for the docker service create command1. To ensure that overlay traffic between service tasks is encrypted, you need to use the --opt encrypted option when creating the overlay network with the docker network create command2. For example, to create an encrypted overlay network named my-net, you can use the following command:

docker network create --driver overlay --opt encrypted my-net

Then, you can use the --network my-net option when creating the service with the docker service create command3. For example, to create a service named my-service using the nginx image and the my-net network, you can use the following command:

docker service create --name my-service --network my-net nginx

docker service create | Docker Docs

Use overlay networks | Docker Docs

Create a service | Docker Docs

PAM is not a supported user authentication method for Universal Control Plane. According to the official documentation, the supported methods are LDAP, Active Directory, SAML 2.0, and local users.

Tagging the image with ‘nginx:immutable’ is not how a user can prevent an image, such as ‘nginx:latest’, from being overwritten by another user with push access to the repository.Tagging the image with ‘nginx:immutable’ will only create a new tag for the image, but it will not prevent the original tag from being overwritten. To prevent an image tag from being overwritten in Docker Trusted Registry, the user can use the DTR web UI to make the tag immutable1. This will prevent anyone from pushing a new image with the same tag, even if they have push access to the repository1. Alternatively, the user can also use the DTR API to make the tag immutable2. References: Prevent tags from being overwritten), DTR API reference)