Running Multiple Node.js Versions in CI with a Single Dockerfile and Jenkins

Using a single Dockerfile to run multiple Node.js versions in CI eliminates the need to install dozens of tools or launch full virtual machines on the CI host; installing Docker alone is sufficient for most programs.

The article explains how to test a project against different Node.js versions and achieve this in Jenkins.

Assuming you have a Jenkins instance that can run Docker, you can start it with a command like:

docker run --name jenkins -itd \
       -p 8081:8080 \
       -p 50000:50000 \
       -v ~/jenkins:/var/jenkins_home \
       -v /var/run/docker.sock:/var/run/docker.sock \
       -v /usr/local/bin/docker:/usr/bin/docker \
       jenkins/jenkins:lts

The project structure is simple:

├── package-lock.json
├── package.json
└── src
    ├── file.js
    └── file.test.js

The project uses npm install to install exact dependency versions from the lock file, and the source code and tests reside in the src folder, with the test task defined in package.json.

To test the project for a specific Node version, you can build an image using the following Dockerfile:

FROM node:12.14
ENV NODE_VERSION=12.14
RUN mkdir -p /app/src
WORKDIR /app
ENV HOME=/app
COPY package.json package-lock.json ./
RUN npm install --ci
COPY src src
CMD npm test

Then configure a Jenkins job to run these commands:

docker build -t node-ci:12.14 .
docker run -it --rm node-ci:12.14

The Dockerfile can be adjusted as needed; you may mount a volume for node_modules or avoid copying code. The official Node image already sets the NODE_VERSION environment variable, so the explicit ENV NODE_VERSION line is optional.

Multiple Node Versions

Each project should define the Node versions to test. Modify the Dockerfile to accept a build argument that specifies the base image:

ARG NODE_VERSION
FROM node:$NODE_VERSION

ARG NODE_VERSION
ENV NODE_VERSION=$NODE_VERSION
RUN mkdir -p /app/src
WORKDIR /app
ENV HOME=/app
COPY package.json package-lock.json ./
RUN npm install --ci
COPY src src
CMD npm test

A script can iterate over the defined versions, passing the NODE_VERSION build argument to build and run each image:

#!/bin/bash -e

versions="10.16 12.14"
for version in $versions; do
  echo "========== node $version ==========="
  docker build -t node-ci:$version --build-arg NODE_VERSION=$version .
  docker run -it --rm node-ci:$version
done

This approach enables a single Dockerfile to run CI jobs for multiple Node versions. Using Docker containers in Jenkins makes configuring and running CI environments highly flexible, and the same ARG + FROM pattern can be applied to other languages or technologies.