HIGH AVAILABILITY WITH DOCKER SWARM

Build high availability for top up game service as a solution to reduce excessive use of resources on the server side. Using HAProxy with roundrobin algorithm.

Created by Muhammad Zaidan.

Table of Contents

• Getting Started
  • Create VM
  • Install Docker
  • Setup User
• Setup App Source Code
• Initialization Swarm
  • Manager Node
  • Worker Node
• Build & Push Image
  • Database
  • App
• Deploy Stack
• Monitoring
• Test Application

Getting Started

We need to setup 3 Virtual Machine using VirtualBox, then install docker & setup user to run docker command without root privileged.

Create VM

In this lab environment we use the Ubuntu 22.04 OS, with the following specifications

No	Virtual Machine	Spesification	NATNetwork	Host-Only Network
1	Manager-01	1vcpu, 2GB Ram	192.168.16.10/24	16.16.16.10/24
2	Worker-01	1vcpu, 1GB Ram	192.168.16.11/24	16.16.16.11/24
3	Worker-02	1vcpu, 1GB Ram	192.168.16.12/24	16.16.16.12/24

There are 2 networks, namely NAT Network for internet access needs and Host-Only Network for remote VM needs from the Host and used for communication between vm.

NATNetwork :

Host-Only Network :

Edit /etc/netplan/00-installer-config.yaml on each node :

Apply network configuration & change hostname

sudo netplan apply
sudo hostnamectl hostname manager-01

sudo netplan apply
sudo hostnamectl hostname worker-01

sudo netplan apply
sudo hostnamectl hostname worker-02

Map host in /etc/hosts on each node

Create a ssh-keygen on windows host so you can ssh without a password

PS C:\Users\Zai> ssh-keygen
PS C:\Users\Zai> type $env:USERPROFILE\.ssh\id_rsa.pub | ssh zai@16.16.16.10 "cat >> .ssh/authorized_keys"

Check if the host can access without using a password (passwordless).

PS C:\Users\Zai> ssh zai@16.16.16.10 "whoami; hostname"
zai
manager-01
PS C:\Users\Zai>

Install Docker

There is two method to install Docker Engine, using docker install script or using script that i made.

1. Docker install script from docker.com

curl -sSL https://get.docker.com/ | sudo sh

2. Docker install script from my git repository

git clone https://github.com/zaidanm16/docker-ha.git
cd installation_docker
sudo chmod u+x install-jammy.sh
sudo ./install-jammy.sh

Test Installed Docker Engine

docker version
docker info
sudo systemctl status docker

Setup User

Add user to docker group, so user can run docker command without root privileged.
Run user.sh from my git repository

sudo chmod u+x user.sh
sudo ./user.sh

or you can manually run

sudo usermod -aG docker $USER
sudo chmod 666 /var/run/docker.sock

Setup App Source Code

Move all your application source code into the web/app directory

cd web/app
git clone https://github.com/zaidanm16/widan-store.git .

Initialization Swarm

Steps to initialization docker swarm cluster with 1 manager node and 2 worker node

Manager Node

You need login to dockerhub with your account then init the swarm cluster

docker login -u [username]
docker swarm init --advertise-addr 16.16.16.10

Copy command docker join, token will be used by worker node

docker swarm join-token worker

Run this command after worker node already join

docker node ls

Worker Node

You can get your swarm [TOKEN] from manager node

docker swarm join --token [TOKEN] 16.16.16.10:2377

Build & Push Image

In this section we will build image for our application & push it to docker hub

Database

Build database image using Dockerfile. Before build the image, edit the Dockerfile according to your needs. I'm using mariadb image with version 10.7.8. You can read comments in the Dockerfile, to see explanation for every steps in building the image.
Note :

[username] is your docker hub account
[image-name] is your image name
[tag] is your image tag or your image version
[path] is path to Dockerfile, if Dockerfile is in the same directory you can use dot (.)

cd db
docker build -t [username]/[image-name]:[tag] [path]

So mine is :

docker build -t kevinmz/mariadb:10.7.8 .

After building succeed, you can push the image to dockerhub

docker push [username]/[image-name]:[tag]

So mine is :

docker push kevinmz/mariadb:10.7.8

App

Build your application using Dockerfile. Before build the image, edit the Dockerfile according to your needs. I'm using php image with version 8.1 and using Apache HTTPD as web Server. You can read comments in the Dockerfile, to see explanation for every steps in building the image.
Note :

[username] is your docker hub account
[image-name] is your image name
[tag] is your image tag or your image version
[path] is path to Dockerfile, if Dockerfile is in the same directory you can use dot (.)

cd web
docker build -t [username]/[image-name]:[tag] [path]

So mine is :

docker build -t kevinmz/app-widan:v1 .

After building succeed, you can push the image to dockerhub

docker push [username]/[image-name]:[tag]

So mine is :

docker push kevinmz/app-widan:v1

Deploy Stack

Before deploy the stack, you need to configure haproxy.conf according your needs.
Deploy your stack application in widan.yml & create secret for db password in widan.yml

• Using script to deploy & create secret

sudo chmod u+x deploy.sh
sudo ./deploy.sh

• Manually create secret & deploy stack

echo '[your_password]' | docker secret create mysql_root_password -
docker stack deploy -c [compose-file] [stack-name] --with-registry-auth

Example :

echo 'pa$$w0rd' | docker secret create mysql_root_password -
docker stack deploy -c widan.yml widan --with-registry-auth

After deploy succeed, run docker service to see that service is replicated & running or not.

docker service ls

You can check each service

docker service ps widan_web
docker service ps widan_db
docker service ps widan_lb

Run the Application from Windows Host at http://[manager-ip]
http://16.16.16.10

Monitoring

See your haproxy load balancing stats at http://[manager-ip]/haproxy
http://16.16.16.10/haproxy

Login using credentials that you create at haproxy.cfg

Test Application

Testing Performance of the Application

BELUM BERES

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