Install node and npm with nvm using Docker.

build.sh

#!/usr/bin/env bash

# confirm docker daemon is running and connected
docker version

# build the image based on the Dockerfile and name it `nvm`
docker build -t nvm .

# confirm image is present
docker images

# enter container terminal
docker run -it nvm bash

Dockerfile

# set the base image to Debian
# https://hub.docker.com/_/debian/
FROM debian:latest

# use bash so we can source files
SHELL ["/bin/bash", "-c"]

# update the repository sources list
# and install dependencies
RUN apt-get update \
    && apt-get install -y curl \
    && apt-get -y autoclean

# nvm environment variables
ENV NVM_DIR /usr/local/nvm
ENV NVM_VERSION 0.37.2
ENV NODE_VERSION 15.5.0

# install node via nvm
RUN mkdir -p ${NVM_DIR} \
    && curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v${NVM_VERSION}/install.sh | bash \
    && source ${NVM_DIR}/nvm.sh \
    && nvm install ${NODE_VERSION} \
    && nvm alias default ${NODE_VERSION}

# add node and npm to path so the commands are available
ENV NODE_PATH ${NVM_DIR}/versions/node/v${NODE_VERSION}/lib/node_modules
ENV PATH ${NVM_DIR}/versions/node/v${NODE_VERSION}/bin:$PATH

# confirm node installation
RUN node --version \
    && npm --version