Swarm vs Kubernetes decision in Docker - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize a Docker Swarm cluster on the manager node.

Docker

docker swarm [1]

Drag options to blanks, or click blank then click option'

Alaunch

Binit

Ccreate

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'start' instead of 'init' which does not initialize the swarm.

Using 'create' or 'launch' which are not valid swarm commands.

The command docker swarm init initializes a new Swarm cluster on the current node.

2fill in blank

medium

Complete the command to join a worker node to an existing Swarm cluster using the token.

Docker

docker swarm join --token [1] manager-node-ip:2377

Drag options to blanks, or click blank then click option'

Aworker-token

Binit-token

Cjoin-token

Dmanager-token

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'manager-token' which is for manager nodes only.

Using 'init-token' which is not a valid token name.

The worker-token is used by worker nodes to join the swarm cluster.

3fill in blank

hard

Fix the error in the Kubernetes deployment command to apply a configuration file.

Docker

kubectl [1] -f deployment.yaml

Drag options to blanks, or click blank then click option'

Acreate

Brun

Capply

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'create' which fails if resource exists.

Using 'run' or 'start' which are not valid for applying configs.

The kubectl apply command applies changes from a configuration file to the cluster.

4fill in blank

hard

Fill both blanks to list all running pods in the default namespace with detailed info.

Docker

kubectl [1] pods [2]

Drag options to blanks, or click blank then click option'

Aget

Bdescribe

C--all-namespaces

D-o wide

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'describe' which shows detailed info for one pod, not a list.

Using '--all-namespaces' which lists pods in all namespaces, not default.

The command kubectl get pods -o wide lists pods with extra details in the default namespace.

5fill in blank

hard

Fill all three blanks to create a Docker service with 3 replicas running nginx.

Docker

docker service [1] --replicas [2] [3]

Drag options to blanks, or click blank then click option'

Acreate

B3

Cnginx

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'run' instead of 'create' which is not valid for services.

Using wrong number of replicas or missing image name.

The command docker service create --replicas 3 nginx creates a service with 3 nginx containers.

Practice

1. Which statement best describes Docker Swarm compared to Kubernetes?

easy

A. Docker Swarm is simpler and faster to set up than Kubernetes.

B. Docker Swarm has more features than Kubernetes.

C. Kubernetes is easier for beginners than Docker Swarm.

D. Kubernetes is only for small projects.

Solution

1. Step 1: Understand Docker Swarm's purpose

   Docker Swarm is designed to be simple and quick to start for container orchestration.

2. Step 2: Compare with Kubernetes features

   Kubernetes offers more advanced features and flexibility but is more complex to set up.

3. Final Answer:

   Docker Swarm is simpler and faster to set up than Kubernetes. -> Option A

4. Quick Check:

   Swarm simplicity = B [OK]

Hint: Swarm is simple; Kubernetes is feature-rich [OK]

Common Mistakes:

• Thinking Kubernetes is easier for beginners
• Believing Swarm has more features
• Assuming Kubernetes is only for small projects

2. Which command initializes a Docker Swarm cluster on the current machine?

easy

A. kubectl create swarm

B. kubectl init cluster

C. docker cluster start

D. docker swarm init

Solution

1. Step 1: Recall Docker Swarm initialization command

   The correct command to start a Swarm cluster is docker swarm init.

2. Step 2: Identify incorrect Kubernetes or invalid commands

   kubectl commands are for Kubernetes, and the others are invalid Docker commands.

3. Final Answer:

   docker swarm init -> Option D

4. Quick Check:

   Swarm init command = A [OK]

Hint: Swarm init uses 'docker swarm init' command [OK]

Common Mistakes:

• Using kubectl commands for Docker Swarm
• Typing incorrect Docker commands
• Confusing cluster start with init

3. Given a project requiring complex scaling and self-healing, which orchestration tool output is expected when checking cluster status?

medium

A. Swarm shows detailed pod logs and events like Kubernetes.

B. Swarm shows limited node details and simple service status.

C. Kubernetes shows detailed pod, node, and event information.

D. Kubernetes shows only basic node count without pod info.

Solution

1. Step 1: Understand Kubernetes status output

   Kubernetes provides detailed information about pods, nodes, and events for complex management.

2. Step 2: Compare with Docker Swarm output

   Swarm offers simpler status info, focusing on nodes and services without detailed pod events.

3. Final Answer:

   Kubernetes shows detailed pod, node, and event information. -> Option C

4. Quick Check:

   Kubernetes detailed status = A [OK]

Hint: Kubernetes status is detailed; Swarm is simpler [OK]

Common Mistakes:

• Assuming Swarm shows pod logs like Kubernetes
• Thinking Kubernetes shows only basic info
• Confusing service status details

4. You tried to join a node to a Docker Swarm cluster but got an error. Which fix is most likely correct?

medium

A. Run 'docker swarm join-token worker' on the manager to get the correct token.

B. Restart the Kubernetes API server.

C. Use 'kubectl join node' command instead.

D. Delete the Docker daemon and reinstall.

Solution

1. Step 1: Identify the cause of join error

   Joining a node to Swarm requires a valid join token from the manager node.

2. Step 2: Correct fix for join token error

   Running docker swarm join-token worker on the manager provides the correct token to join.

3. Final Answer:

   Run 'docker swarm join-token worker' on the manager to get the correct token. -> Option A

4. Quick Check:

   Swarm join token fix = C [OK]

Hint: Get join token from manager with 'docker swarm join-token' [OK]

Common Mistakes:

• Using Kubernetes commands for Docker Swarm
• Restarting unrelated services
• Reinstalling Docker unnecessarily

5. Your team is new to container orchestration and needs to deploy a small app quickly with minimal setup. Which tool should you choose and why?

hard

A. Kubernetes, because it has more features for future growth.

B. Docker Swarm, because it is simpler and faster to start.

C. Kubernetes, because it requires less configuration initially.

D. Docker Swarm, because it supports complex multi-cloud setups better.

Solution

1. Step 1: Analyze team skill and project needs

   The team is new and wants quick deployment with minimal setup, favoring simplicity.

2. Step 2: Match tool choice to requirements

   Docker Swarm is simpler and faster to start, ideal for small projects and beginners.

3. Final Answer:

   Docker Swarm, because it is simpler and faster to start. -> Option B

4. Quick Check:

   Simple quick start = D [OK]

Hint: Choose Swarm for quick, simple setups with new teams [OK]

Common Mistakes:

• Choosing Kubernetes for minimal setup
• Assuming Kubernetes is easier for beginners
• Believing Swarm is better for complex multi-cloud