Docker containerization in NestJS

Introduction

Docker helps you package your NestJS app with everything it needs to run. This makes it easy to share and run your app anywhere without setup problems.

You want to run your NestJS app on different computers or servers without installing Node.js or dependencies each time.

You need to share your app with teammates or deploy it to the cloud quickly.

You want to keep your app isolated so it doesn't affect or get affected by other software on the same machine.

You want to test your app in the same environment as production to avoid surprises.

You want to automate deployment with consistent environments.

Syntax

NestJS

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD ["node", "dist/main.js"]

FROM sets the base image with Node.js installed.

WORKDIR sets the folder inside the container where commands run.

Examples

Basic Dockerfile to containerize a NestJS app using Node 18 Alpine image.

NestJS

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD ["node", "dist/main.js"]

Example using Yarn package manager instead of npm.

NestJS

FROM node:18-alpine
WORKDIR /usr/src/app
COPY package.json yarn.lock ./
RUN yarn install --frozen-lockfile
COPY . .
RUN yarn build
EXPOSE 3000
CMD ["node", "dist/main.js"]

Using npm ci for faster, clean installs in CI/CD pipelines.

NestJS

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build
EXPOSE 3000
CMD ["node", "dist/main.js"]

Sample Program

This Dockerfile creates a container for a NestJS app. It uses a small Node.js image, installs dependencies, builds the app, and runs it on port 3000.

NestJS

FROM node:18-alpine

# Set working directory
WORKDIR /app

# Copy package files and install dependencies
COPY package*.json ./
RUN npm install

# Copy all source files
COPY . .

# Build the NestJS app
RUN npm run build

# Expose port 3000
EXPOSE 3000

# Start the app
CMD ["node", "dist/main.js"]

Important Notes

Remember to add a .dockerignore file to exclude node_modules and other unnecessary files to keep the image small.

Use docker build -t your-app-name . to build the image and docker run -p 3000:3000 your-app-name to run it.

Make sure your NestJS app listens on all network interfaces (0.0.0.0) inside the container, not just localhost.

Summary

Docker packages your NestJS app with everything it needs to run anywhere.

Use a Dockerfile to define how to build and run your app inside a container.

Containers help with easy sharing, deployment, and consistent environments.