Manager and worker nodes in Docker - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to initialize a Docker Swarm manager node.

Docker

docker swarm [1]

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

Acreate

Bjoin

Cstart

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'join' instead of 'init' to start the swarm.

The docker swarm init command starts a new swarm and makes the current node a manager.

2fill in blank

medium

Complete the command to add a worker node to the swarm using a token.

Docker

docker swarm [1] --token SWMTKN-1-0-xyz 192.168.1.10:2377

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

Acreate

Bjoin

Cstart

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'init' instead of 'join' to add a worker node.

The docker swarm join command adds a node to an existing swarm as a worker or manager.

3fill in blank

hard

Fix the error in the command to list all nodes in the swarm.

Docker

docker node [1]

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

Alist

Bshow

Cls

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'list' or 'show' which are invalid commands here.

The correct command to list nodes is docker node ls.

4fill in blank

hard

Fill both blanks to create a service that runs on worker nodes only.

Docker

docker service create --name myservice --constraint 'node.role [1] [2]' nginx

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

A==

B!=

Cworker

Dmanager

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' or 'manager' which exclude workers.

The constraint node.role == worker ensures the service runs only on worker nodes.

5fill in blank

hard

Fill all three blanks to update a service to run only on manager nodes with 3 replicas.

Docker

docker service update --replicas [1] --constraint-add 'node.role [2] [3]' myservice

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

Aworker

B3

C==

Dmanager

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'worker' role or wrong operators.

Setting replicas to 3 and constraint node.role == manager updates the service accordingly.