DEV Community: Rhonal Chirinos

Configure an inverse proxy with NGINX for 3 microservices using Docker Compose and Docker Swarm.

Rhonal Chirinos — Sat, 28 Jun 2025 01:40:19 +0000

✅ Task

Configure an inverse proxy with NGINX for 3 microservices using Docker Compose and Docker Swarm.

🐳 Initialize Docker Swarm

Initialize Docker Swarm on your manager node:

docker swarm init

➕ Add Worker Nodes to the Swarm

To add worker nodes to your Swarm, run the following command on each worker node (replace the token and IP with your actual values):

docker swarm join --token <WORKER_TOKEN> <MANAGER_IP>:2377

Tip: Retrieve the worker join token with:
docker swarm join-token worker

🏷️ Label Your Nodes

Label your nodes to specify their roles (e.g., database or worker):

List all nodes:
```
docker node ls 
```

Add a label to a node (replace NODE_ID as needed):

docker node update --label-add db=true NODE_ID
docker node update --label-add worker=true NODE_ID

📝 Example `docker-compose.yml`

Below is an example docker-compose.yml file for your stack:

version: '3.8'

services:
  db:
    image: mongo:latest
    ports:
      - 27017:27017
    volumes:
      - db-data:/data/db
    deploy:
      placement:
        constraints:
          - node.labels.db == true
      resources:
        limits:
          cpus: '8.0'
          memory: 8G

  survey:
    image: rhonalchirinos/exec04-survey:latest
    ports:
      - 3000:3000
    command: sh -c "node /app/src/main.js"
    depends_on:
      - db
    deploy:
      replicas: 3
      resources:
        limits:
          cpus: '1.0'
          memory: 1G
      placement:
        constraints: [ node.labels.worker == true ]

  auth:
    image: rhonalchirinos/exec04-auth:latest
    ports:
      - 3001:3001
    command: sh -c "node /app/src/main.js"
    depends_on:
      - db
    deploy:
      replicas: 3
      resources:
        limits:
          cpus: '1.0'
          memory: 1G
      placement:
        constraints: [ node.labels.worker == true ]
    environment:
      - MONGO_DB=mongodb://db:27017/app
      - PORT=3001

  stats:
    image: rhonalchirinos/exec04-stats:latest
    ports:
      - 3002:3002
    depends_on:
      - db
    deploy:
      replicas: 2
      resources:
        limits:
          cpus: '1.0'
          memory: 1G
      placement:
        constraints: [ node.labels.worker == true ]

  haproxy:
    image: rhonalchirinos/exec04-haproxy:latest
    ports:
      - "80:8080"
    depends_on:
      - stats
      - auth
      - survey
    deploy:
      placement:
        constraints: [ node.role == manager ]

  visualizer:
    image: dockersamples/visualizer:latest
    ports:
      - "8080:8080"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
    deploy:
      placement:
        constraints: [ node.role == manager ]
      replicas: 1

volumes:
  db-data:

🚀 Deploy the Stack

Deploy your stack using the following command:

docker stack deploy -c docker-compose.yml mystack

📌 Notes

Ensure all images are built and available (locally or on a registry) before deploying.
The haproxy service acts as a reverse proxy for your microservices.
The visualizer service provides a UI to visualize your Docker Swarm cluster.
Adjust resource limits and replica counts as needed for your environment.

Display a Docker Swarm cluster with 3 nodes

Rhonal Chirinos — Mon, 16 Jun 2025 00:01:21 +0000

✅ Task

Display a Docker Swarm cluster with 3 nodes

📦 Create the API

Folder: swarm-api

swarm-api/Dockerfile

FROM node:22.13-alpine

WORKDIR /app

COPY package*.json ./
RUN npm install && npm audit fix --force

COPY . .

EXPOSE 3000

CMD ["node", "main.js"]

swarm-api/package.json

{
  "name": "swarm-api",
  "version": "1.0.0",
  "main": "main.js",
  "license": "MIT",
  "dependencies": {
    "express": "^5.1.0",
    "pg": "^8.16.0"
  }
}

swarm-api/main.js

const express = require('express');
const { Pool } = require('pg');

const app = express();
const port = process.env.PORT || 3000;

const pool = new Pool({
  host: process.env.PGHOST || 'postgres',
  user: 'postgres',
  password: process.env.PGPASSWORD || 'secret',
  database: 'postgres',
  port: 5432,
});

app.get('/', async (req, res) => {
  const result = await pool.query('SELECT NOW()');
  res.json({ message: 'Hello from API', time: result.rows[0].now });
});

app.listen(port, '0.0.0.0', () => {
  console.log(`API running on port ${port}`);
});

🛠️ Build the Docker image

docker build --tag rhonalchirinos/hello-api:latest .

☁️ Push to Docker Hub

docker login
docker push rhonalchirinos/hello-api:latest

🌐 Create an Overlay Network

docker network create -d overlay hello-net

ℹ️ Why an overlay network? Overlay networks allow containers and services to communicate across multiple Docker nodes in a Swarm. This eliminates the need for OS-level routing.

🐳 Initialize Docker Swarm

docker swarm init

➕ Add Worker Nodes to the Swarm

docker swarm join --token SWMTKN-1-xxxxx 192.168.64.6:2377

📌 You can get the worker token using:

docker swarm join-token worker

🛢️ Create a PostgreSQL Service

docker service create \
  --name postgres \
  --env POSTGRES_PASSWORD=secret \
  --mount type=volume,source=testdb,target=/var/lib/postgresql/data \
  --network hello-net \
  postgres

🚀 Deploy the API Service in Swarm

First, check if services are listed:

docker service ls

Then create the service:

docker service create \
  --name some-api \
  --replicas 3 \
  --publish 3000:3000 \
  --network hello-net \
  rhonalchirinos/hello-api:latest

You can inspect the published ports with:

# inspect ports
docker service inspect some-api --format '{{json .Endpoint.Ports}}' | jq

🧪 Test the API

curl <http://localhost:3000>

How to Configure Docker Volumes for MySQL

Rhonal Chirinos — Sat, 07 Jun 2025 01:00:35 +0000

Docker containers are ephemeral by default—this means that any data stored inside a container is lost when the container is stopped or removed. To persist data, Docker provides volumes, which allow you to store and reuse data across container restarts.

Volumes are especially useful for databases like MySQL, where persistent storage is essential. This guide is a quick teaser on how to use Docker volumes to persist MySQL data.

Create a Volume

docker volume create --name storage_test

List All Volumes

docker volume ls

Where Does Docker Store My Volume Data?

docker volume inspect storage_test

💡 This command shows detailed information about the volume, including the path on your host system where the data is stored.

Remove a Volume

docker volume rm storage_test

⚠️ You can’t remove a volume that’s currently in use by a running container.

Run a MySQL Container with a Volume

docker volume create --name storagedb

docker run --name mysql-01 \
  -v storagedb:/var/lib/mysql \
  -e MYSQL_ROOT_PASSWORD=123456 \
  -d mysql:latest

Execute a SQL Script Inside the Container

docker exec -i mysql-01 \
sh -c 'exec mysql -uroot -p"$MYSQL_ROOT_PASSWORD"' < ./mysql/databases.sql

Notes

💡 Docker volumes are a powerful way to persist and share data across containers. You can also use the same volume in multiple containers if needed.

Thanks for reading! ✨

Build an API on a Docker image that is less than 20 MB

Rhonal Chirinos — Mon, 26 May 2025 14:52:38 +0000

In this exercise, we aim to build a lightweight Dockerized API that weighs less than 20 MB. To achieve this, we'll use a multi-stage build and Alpine Linux — a minimal base image designed small containers. Our API will be written in Go.

Project Structure

exec01/
├── Dockerfile
├── go
│   ├── go.mod
│   └── main.go

Dockerfile

FROM golang:1.24.3-alpine AS builder
ARG TARGETARCH
WORKDIR /app
COPY ./go .
RUN go build -o app && chmod +x app

FROM alpine:latest
WORKDIR /app 
COPY --from=builder /app/app /app/app
EXPOSE 8080
CMD ["/app/app"]

Go Module File

module exec01/helloworld
go 1.24.3

Main Application (Go)

package main

import (
  "fmt"
  "net/http"
)

func main() {
  http.HandleFunc("/", Handler)
  http.ListenAndServe(":8080", nil)
}

func Handler(w http.ResponseWriter, r *http.Request) {
  fmt.Fprintf(w, "Hello, World!")
}

Notas de Codigo limpio

Rhonal Chirinos — Sat, 20 Jan 2024 02:35:31 +0000

Link:

libro

Intro: Invita a esforzarse y hacer un trabajo duro, tomare tiempo para leer con calma y paciencia cada palabra de este libro.

Sobre la imagen: interesante.

Codigo limpio: Ley de LeBlanc "Despues es igual anunca".

Python create venv

Rhonal Chirinos — Mon, 14 Aug 2023 15:24:16 +0000

sudo apt-get install python-virtualenv

virtualenv --python=/usr/bin/python3.4 venv

Composer use global binaries

Rhonal Chirinos — Sun, 14 May 2023 19:23:59 +0000

When you install composer, you need to link the vendor/bin folder for use script when you need run a script.

echo 'export PATH="$PATH:$HOME/.composer/vendor/bin"' >> ~/.bashrc

after

source ~/.bashrc

That's it!

Install my development environment In Prestashop

Rhonal Chirinos — Sat, 13 May 2023 03:44:50 +0000

Hello my friend,

The environment is very important, first to create a environment for make a module in PS, new need install Docker and to know use it.

Configure your environment

1 Open your terminal

2 Update the package Repository

sudo apt update

3 Install prerequisite Packages

sudo apt install apt-transport-https ca-certificates curl software-properties-common -y

4 Add GPG key

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

5 Add Docker Repository

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

6 Specify Installation Source

sudo apt-cache policy docker-ce

7 Install Docker

sudo apt install docker-ce -y

8 Check Docker Status

sudo systemctl status docker

9 Learn how to use docker

10 Install PrestaCLI

composer global require rhonalchirinos/prestacli

That's it!

Modules in Prestashop, Easy and Fast!

Rhonal Chirinos — Sat, 08 Apr 2023 22:27:24 +0000

Prestashop Module

PrestaShop (PS) is a free and open source content management system... Go to the more important, Present you a small command line interface to create a new module for PS in a sample command

Install my development environment
Create a module for PS
Understand how to work hooks in PS
How to create release of my module
I don't know that put here.

I have been working with PS not because i want to if not why do I need...

Good luck

Github ssh key

Rhonal Chirinos — Sun, 26 Mar 2023 20:50:53 +0000

git -c core.sshCommand="ssh -i /home/rhonal/.ssh/idkey" clone git@github.com:front.git

git config --add --local core.sshCommand 'ssh -i <<< PATH_TO_SSH_KEY >>>'

DEV Community: Rhonal Chirinos

Configure an inverse proxy with NGINX for 3 microservices using Docker Compose and Docker Swarm.

✅ Task

🐳 Initialize Docker Swarm

➕ Add Worker Nodes to the Swarm

🏷️ Label Your Nodes

📝 Example docker-compose.yml

🚀 Deploy the Stack

📌 Notes

Display a Docker Swarm cluster with 3 nodes

✅ Task

📦 Create the API

🛠️ Build the Docker image

☁️ Push to Docker Hub

🌐 Create an Overlay Network

🐳 Initialize Docker Swarm

➕ Add Worker Nodes to the Swarm

🛢️ Create a PostgreSQL Service

🚀 Deploy the API Service in Swarm

🧪 Test the API

How to Configure Docker Volumes for MySQL

Create a Volume

List All Volumes

Where Does Docker Store My Volume Data?

Remove a Volume

Run a MySQL Container with a Volume

Execute a SQL Script Inside the Container

Notes

Build an API on a Docker image that is less than 20 MB

Project Structure

Notas de Codigo limpio

Python create venv

Composer use global binaries

Install my development environment In Prestashop

Configure your environment

1 Open your terminal

2 Update the package Repository

3 Install prerequisite Packages

4 Add GPG key

5 Add Docker Repository

6 Specify Installation Source

7 Install Docker

8 Check Docker Status

9 Learn how to use docker

10 Install PrestaCLI

Modules in Prestashop, Easy and Fast!

Prestashop Module

Github ssh key

📝 Example `docker-compose.yml`