Lab 2.4 - Containerize our application

DATE:

Friday, March 29, 2024

TAGS:

Docker

Container

Python

Next.js

In this lab, we will containerize our application. We write Dockerfile for our Python FastAPI application as well as our Next.js frontend application. Then we will build an image from our Dockerfile and run a container from the Image. At the end of this lab, we will have our application runing with docker compose command.

Objectives

Write Dockerfile for Python FastAPI application
Build an image for FastAPI application
Run a container that starts up our FastAPI application
Write Dockerfile for Next.JS application.
Build an image from Next.JS Dockerfile
Run a container that starts up our Next.JS application
Write a docker-compose.yaml file to run both applications
Start both applications with docker-compose up command

Instructions

1. Write Dockerfile for Python FastAPI application

We write following Dockerfile for our Python FastAPI application.

FROM python:3.11-slim

WORKDIR /app

COPY requirements.txt .

RUN pip install --no-cache-dir -r requirements.txt

COPY . .

ENTRYPOINT [ "uvicorn", "main:app", "--reload"] 
CMD ["--port", "5000", "--host", "0.0.0.0"]
EXPOSE 5000

As we see the Dockerfile, uses requirements.txt file to install the dependencies. Then it copies the source code to the container and runs the server. The content of requirements.txt file is as follows.

fastapi==0.110.0
uvicorn==0.26.0

2. Build an image for FastAPI application

We build an image from the Dockerfile using the following command.

docker build -t fastapi-app .

3. Run a container that starts up our FastAPI application

We run a container from the image using the following command.

docker run -d -p 5000:5000 fastapi-app

4. Write Dockerfile for Next.JS application

We write following Dockerfile for our Next.JS application.

FROM node:21-alpine3.18

LABEL MAINTAINER="Mehrshad Lotfi <mehrshad@optiop.org>"

WORKDIR /usr/src

COPY ["package.json", "."]

RUN npm install

COPY [".", "/usr/src"]

RUN npm run build

EXPOSE 3000

CMD ["npm", "run", "start"]

5. Build an image from Next.JS Dockerfile

We build an image from the Dockerfile using the following command.

docker build -t nextjs-app .

6. Run a container that starts up our Next.JS application

We run a container from the image using the following command.

docker run -d -p 3000:3000 nextjs-app

7. Write a `docker-compose.yaml` file to run both applications

We write a docker-compose.yaml file to run both applications.

version: '3.8'
services:
  backend:
    build: backend
    ports:
      - "5000:5000"
  frontend:
    build: frontend
    ports:
      - "3000:3000"

8. Start both applications with `docker-compose up` command

We start both applications using the following command.

docker-compose up