Introduction

Docker Swarm is a powerful clustering and orchestration tool that allows you to manage and scale Docker containers across multiple nodes.

In this guide, we’ll cover the basics of Docker Swarm — including setting up a Swarm, joining nodes, deploying services, scaling, updating, and more.

Whether you’re new to Docker or looking to expand your container orchestration skills, this article will give you a solid foundation to get started with Docker Swarm.

📺 For a visual demonstration of these steps, check out this video tutorial:
Docker Swarm Basics - YouTube

Prerequisites

Before diving into Docker Swarm, make sure you have the following:

• A basic understanding of Docker concepts and commands.
• Three machines (virtual or physical): one as the manager node and two as worker nodes.
• All machines should have Docker installed.

Setting Up Docker Swarm

1. Initialize the Swarm on the manager node:

docker swarm init --advertise-addr <MANAGER_NODE_IP>

2. Join the worker nodes to the Swarm:

On each worker node, run the following command (replace <MANAGER_NODE_IP> with the IP address of the manager node):

docker swarm join --token <TOKEN> <MANAGER_NODE_IP>:2377

3. Verify the Swarm status:

On the manager node, run:

docker node ls

Deploying and Managing Services in Docker Swarm

Deploy a service:

docker service create --name my-nginx --replicas 3 -p 80:80 nginx

List services:

docker service ls

Scale a service:

docker service scale my-nginx=5

Update a service:

docker service update --image nginx:latest my-nginx

Inspect a service:

docker service inspect my-nginx

Remove a service:

docker service rm my-nginx

Conclusion

Docker Swarm provides a simple yet powerful solution for orchestrating containers in a distributed environment.

With the ability to deploy, scale, update, and manage services across multiple nodes, Docker Swarm empowers developers and system administrators to build resilient and scalable applications.

Remember to experiment and explore additional features such as rolling updates, service rollback, and service constraints to make the most out of Docker Swarm.

Happy container orchestration! 🐳✨

References

• Docker Swarm Overview
• Docker Official Documentation