README.md

NestJS Production docker file

This Dockerfile is used to build a clean and lightweight image of your NestJS application. please follow the instruction to understand what is happening clearly.

There is a NestJS example project that you can use and build the image after cloning the repository too.

How to test and build?

First, make a clone from this repository using:

git clone https://github.com/devopshobbies/docker-templates.git

Build your image using the command:

docker build -t nestjs-temp docker-templates/01-JavaScript-Typescript-Backend/frameworks/nestjs

Stage one, Build the NestJS application

Identify the NodeJS alpine as a builder

FROM node:16-alpine as builder

Set NODE_ENV to build

This line sets the NODE_ENV environment variable to build. This tells Node.js that we are in a build environment, which can be used to optimize the build process.

ENV NODE_ENV build

Build commands

These lines set the user to node (a non-root user), create a working directory at /home/node, and copy the package.json and package-lock.json files to the working directory. The npm ci command installs the project's dependencies based on the package-lock.json file.

USER node
WORKDIR /home/node

COPY package\*.json ./
RUN npm ci

COPY --chown=node:node . .
RUN npm run build \
 && npm prune --production

Also, if you are using yarn package manager instead of npm, likely to change this part to:

USER node
WORKDIR /home/node

COPY package.json ./

# You have to copy the yarn.lock file
COPY yarn.lock ./
RUN yarn install --immutable --immutable-cache --check-cache

COPY --chown=node:node . .
RUN yarn build \
  && yarn install --production --ignore-scripts --prefer-offline

Stage two, create the lightweight image

set the base image to node:16-alpine

FROM node:16-alpine

Set NODE_ENV to build

ENV NODE_ENV production

Copy the necessary files.

These lines copy the package.json and package-lock.json files, the node_modules directory, and the dist directory from the builder stage to the current stage. The --from=builder flag specifies that the files should be copied from the builder stage, and the --chown=node:node flag sets the ownership of the copied files to the node user.

USER node
WORKDIR /home/node

COPY --from=builder --chown=node:node /home/node/package\*.json ./
COPY --from=builder --chown=node:node /home/node/node_modules/ ./node_modules/
COPY --from=builder --chown=node:node /home/node/dist/ ./dist/

If you are using yarn, add this extra line to copy the yarn.lock file.

COPY --from=builder --chown=node:node /home/node/yarn.lock ./

The final step, add the startup command

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