Manager and worker nodes in Docker - Mini Project: Build & Apply

Manager and Worker Nodes in Docker Swarm

📖 Scenario: You are setting up a Docker Swarm cluster to manage containerized applications. The cluster has one manager node and one worker node. You will create the initial swarm, add a worker node, and verify the nodes in the swarm.

🎯 Goal: Learn how to initialize a Docker Swarm manager node, add a worker node to the swarm, and list the nodes in the swarm.

📋 What You'll Learn

Use docker swarm init to create the manager node

Use docker swarm join with the correct token to add a worker node

Use docker node ls to list all nodes in the swarm

💡 Why This Matters

🌍 Real World

Docker Swarm is used to manage and orchestrate containers across multiple machines, making it easier to deploy and scale applications.

💼 Career

Understanding manager and worker nodes in Docker Swarm is essential for roles involving container orchestration, cloud infrastructure, and DevOps automation.

1

Initialize the Docker Swarm Manager Node

Run the command docker swarm init --advertise-addr 192.168.1.100 to initialize the current machine as the manager node with the IP address 192.168.1.100.

Docker

# Run the command to initialize the swarm manager node
# Your code here

Need a hint?

The --advertise-addr option sets the IP address the manager node uses to communicate with other nodes.

2

Get the Worker Join Token

Run the command docker swarm join-token worker -q on the manager node to get the worker join token.

Docker

docker swarm init --advertise-addr 192.168.1.100
# Run the command to get the worker join token
# Your code here

Need a hint?

The -q option outputs only the token string, which is needed to join worker nodes.

3

Join the Worker Node to the Swarm

On the worker node, run the command docker swarm join --token 192.168.1.100:2377 replacing <token> with the token from Step 2 to join the swarm.

Docker

docker swarm init --advertise-addr 192.168.1.100
docker swarm join-token worker -q
# Run the command on the worker node to join the swarm
# Your code here

Need a hint?

Replace <token> with the actual token string you got from the manager node.

4

List All Nodes in the Swarm

On the manager node, run docker node ls to list all nodes in the swarm and verify the worker node has joined.

Docker

docker swarm init --advertise-addr 192.168.1.100
docker swarm join-token worker -q
docker swarm join --token SWMTKN-1-0abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890 192.168.1.100:2377
# Run the command to list all swarm nodes
# Your code here

Need a hint?

The docker node ls command shows all nodes and their roles in the swarm.