Docker Swarm with NFS and MySQL

Introduction

Docker Swarm is a clustering and orchestration solution provided by Docker for managing a cluster of Docker nodes. It allows you to deploy, scale, and manage containers across multiple hosts. In this article, we will explore how to use Docker Swarm with NFS (Network File System) and MySQL, and understand the benefits it offers for containerized applications.

What is Docker Swarm?

Docker Swarm is a native clustering and orchestration solution for Docker. It allows you to create and manage a swarm of Docker nodes, which can be used to deploy and scale containerized applications. Docker Swarm provides a single API endpoint to manage the entire Swarm cluster, making it easy to deploy and manage applications across multiple hosts.

Setting up Docker Swarm with NFS and MySQL

To set up Docker Swarm with NFS and MySQL, we need to follow these steps:

  1. Set up a Docker Swarm cluster: First, we need to set up a Docker Swarm cluster using Docker Machine or any other method of your choice. This will involve creating multiple Docker hosts (nodes).

  2. Install and configure NFS: Next, we need to install and configure NFS on all the Docker hosts. NFS allows us to share a directory across multiple hosts, which is required for persistent storage in a Docker Swarm cluster. We can use the following commands on each Docker host to install and configure NFS:

$ sudo apt-get update
$ sudo apt-get install nfs-kernel-server
$ sudo mkdir /nfsshare
$ sudo chown nobody:nogroup /nfsshare
$ sudo chmod 777 /nfsshare
$ echo "/nfsshare *(rw,sync,no_subtree_check)" | sudo tee -a /etc/exports
$ sudo exportfs -a
  1. Create a stack file: We need to create a stack file (docker-compose.yml) that defines our services, including the NFS volume and the MySQL service. Here is an example of a stack file:
version: '3.8'

services:
  nfs:
    image: itsthenetwork/nfs-server-alpine:latest
    volumes:
      - nfsshare:/nfsshare
    deploy:
      mode: global

  mysql:
    image: mysql:latest
    volumes:
      - nfsshare:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=secret
    deploy:
      replicas: 3
      restart_policy:
        condition: on-failure

volumes:
  nfsshare:
    driver_opts:
      type: nfs
      o: addr=<nfs-server-ip>,rw
      device: ":/nfsshare"
  1. Deploy the stack: Once the stack file is created, we can deploy it on the Docker Swarm cluster using the following command:
$ docker stack deploy -c docker-compose.yml myapp

This command will deploy the stack and create the required services. The NFS service will be deployed on all the Docker hosts, and the MySQL service will be deployed on three replicas.

  1. Verify the deployment: After the stack is deployed, we can verify the deployment by checking the status of the services and the NFS volume. We can use the following commands to check the status:
$ docker service ls
$ docker volume ls

Benefits of Docker Swarm with NFS and MySQL

Using Docker Swarm with NFS and MySQL provides several benefits for containerized applications:

  1. Scalability: Docker Swarm allows us to easily scale our application by adding or removing nodes from the swarm. This ensures that our application can handle increased traffic and load.

  2. High availability: Docker Swarm provides high availability for our services by automatically rescheduling containers in case of failures. If a container fails, Docker Swarm will automatically restart it on a healthy node.

  3. Data persistence: By using NFS and MySQL together, we can ensure data persistence across the Docker Swarm cluster. The NFS volume allows us to share data across multiple hosts, and the MySQL service ensures that our application's data is stored and accessible.

  4. Easy management: Docker Swarm provides a single API endpoint to manage the entire cluster, making it easy to deploy, update, and monitor our application. We can use Docker commands or Docker Swarm UI to manage the swarm.

Conclusion

Docker Swarm with NFS and MySQL is a powerful combination for deploying and managing containerized applications. It allows us to easily scale our application, ensure high availability, and provide data persistence across the swarm. By following the steps mentioned in this article, you can set up your own Docker Swarm cluster with NFS and MySQL and take advantage of the benefits it offers. Happy containerizing!

State Diagram

stateDiagram
    [*] --> Ready
    Ready --> Running
    Running --> Stopped
    Stopped --> [*]

Gantt Chart

gantt
    title Docker Swarm with NFS and MySQL
    dateFormat  YYYY-MM-DD
    section Setup
    Install and configure NFS      :done, 2021-01-01, 1d
    Create a stack file            :done, 2021-01-02, 1d
    Deploy the stack               :done, 2021-01-03, 1d
    Verify the deployment          :done