Which Docker Certified Associate questions should I review first?

This test does not have enough answers yet for a ranking. Start with these topics: Swarm Init & Listen Addr, Add & Copy, Apt & Docker CE.

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Review set

Hardest Docker Certified Associate questions

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Not enough answers yet to rank this test. A question needs 20 answers in the last 90 days to get a rank. The questions below are a review set in no ranked order.

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Review question 1

Swarm Init & Listen Addr

Orchestration

Not ranked

An administrator runs docker swarm init --advertise-addr 10.0.0.5 and passes no --listen-addr flag. On which address and port does the new manager listen for swarm management traffic?

Correct answer

C. 0.0.0.0:2377, the documented default listen address, so it accepts connections on all interfaces on port 2377

C is correct: the swarm init reference lists 0.0.0.0:2377 as the default for --listen-addr. A is wrong because port 7946 is used for node discovery, not for manager API traffic, and the listen address is not derived from the advertised one. B is wrong because the default is 0.0.0.0, not the loopback address, so remote nodes can connect. D is wrong because port 4789 carries overlay network traffic, not swarm management traffic.

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Review question 2

Add & Copy

Image Creation, Management, and Registry

Not ranked

A Dockerfile contains the line ADD app.tar.gz /opt/app/ and app.tar.gz is a gzip-compressed tar archive in the build context. What does the build place in /opt/app/?

Correct answer

B. The unpacked contents of the archive, because ADD extracts local tar archives by default

The correct answer is B. The unpacked contents of the archive, because ADD extracts local tar archives by default. A is wrong because ADD unpacks a local tar archive by default, while COPY leaves it packed. C is wrong because ADD accepts local files and URLs alike, not URLs only. D is wrong because extraction is the default for local archives, and no --extract flag is required.

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Review question 3

Apt & Docker CE

Installation and Configuration

Not ranked

A Ubuntu server has the distribution package that provides the Docker command installed. An administrator now wants to install Docker Engine from Docker's own apt repository. Which package do the official instructions tell the administrator to remove first?

Correct answer

C. docker.io, because the distribution package conflicts with the docker-ce packages from Docker

The correct answer is C. The official Ubuntu instructions list docker.io, docker-compose, docker-compose-v2, docker-doc, docker-buildx, podman-docker, and any earlier containerd or runc as unofficial packages to remove before installing from Docker's repository. A is wrong because ca-certificates is a prerequisite that the instructions install with apt, not a package to remove. B is wrong because docker-buildx-plugin is one of the packages the instructions install from Docker's repository; only the older docker-buildx package from the distribution conflicts. D is wrong because containerd.io is itself part of the install command; only a previously installed distribution containerd or runc must be removed.

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