9 Week 7/8 (20/27-Nov-2025)

9.1 Create a Nginx Cluster

Using the contents explained in section Seção 6.1.2 create two different containers of nginx, called nginx1and nginx2, each, using a different external port.
Make sure each container map a volume to different directories and containing a different index.html file. Change the contents of this file to identify the nginx node. This is needed to clearly distinguish the contents of each nginx node.
Verification: Open http://localhost:port in a web browser to see the content of the mounted directory on each cluster node, where the port parameter is the value of each node.
Since nginx1 and nginx2 are supposed to have the same application contents, how can we distribute the traffic between the two nodes ?
- The answer is: Using a Reverse Proxy to perform load balancing. A Reverse Proxy like Traefik.

9.2 Traefik Installaltion

Please refer to section Capítulo 4 to install Traefik.

9.3 Load Balancing (using Traefik)

Implement a load balancing mechanism using Traefik to distribute the traffic between each nginx cluster nodes.
On your hard-drive, create a directory called dynamic inside /traefik. On Windows use C:/traefik. Use any other location if you wish.
Change the traefik.yml file to include the following contents:

## traefik.yml

global:
  checkNewVersion: true
  sendAnonymousUsage: false

log:
  level: DEBUG

accessLog: {}

#tracing:
#  elastic: {}

metrics:
  prometheus: {}

ping: {}

# API and dashboard configuration
api:
  dashboard: true
  insecure: true

# Docker entrypoints backend
entryPoints:
  web:
    address: :80

  web-secure:
    address: :443
    
# Docker configuration backend
providers:
  docker:
    defaultRule: 'Host(`{{ if index .Labels "com.docker.compose.service" }}{{ index .Labels "com.docker.compose.service" }}.aritlab.com{{ else }}{{ trimPrefix `/` .Name }}.aritlab.com{{ end }}`)'
    endpoint: unix:///var/run/docker.sock
    # For Windows
    # endpoint: "npipe:////./pipe/docker_engine"
    watch: true
    exposedByDefault: true
    
  file:
    directory: "/etc/traefik/dynamic"
    watch: true

Inside directory /traefik/dynamic create the file dynamic.yml with the following contents:
From Docker, get the ip addresses from each nginxcluster node.

## DYNAMIC CONFIGURATION
http:
  routers:
    labcluster:
      rule: "Host(`www.aritlab.com`)"
      service: labcluster
      
  services:
    labcluster:
      loadBalancer:
        servers:
            - url: "http://ip_address_nginx1:port1/"
            - url: "http://ip_address_nginx2:port2/"

Use again the following Docker command to install and run Traefik:

docker run -d --restart always -p 80:80 -p 8080:8080 -v /var/run/docker.sock:/var/run/docker.sock -v /traefik:/etc/traefik --network traefik_network --name traefik traefik:latest

In your hosts file, map the name www.aritlab.com to your own host hostname/ip address.

Open a web browser and navigate to http://www.aritlab.com. You should see now that Traefik is redirecting you either to nginx1 or nginx2.