Considering Image Size
A Brief comparison of image size where the only thing changing between images is the first line of the dockerfile, the FROM command.
For reference, Docker Node Images.
Some Pre-Built Images
| Base Image | Output Size | 1 Dot = 25MB (Micro Viz) |
|---|---|---|
| node:18 | 950MB | .... .... .... .... .... .... .... .... .... .. |
| node:18-slim | 243MB | .... .... .. |
| node:18-alpine | 176MB | .... ... |
| alpine as the root | 59MB | .. |
FROM node:18
# FROM node:18-slim
# FROM node:18-alpine
USER node
RUN mkdir /home/node/code
WORKDIR /home/node/code
COPY package-lock.json package.json ./
RUN npm ci
COPY . .
EXPOSE 3000
# run the server
CMD ["node", "index.js"]More Customized
Here are a couple more customized images to illustrate how building an image more "from scratch" can reduce the size EVEN MORE!
Alpine as the Root
# setup alpine & install node & npm
FROM alpine:3.12
RUN apk add --update nodejs npm
# -S: Create a system group
# -G Group
# add a group called node
# add a user node TO the node group
RUN addgroup -S node && adduser -S node -G node
USER node
# setup the image directories
RUN mkdir /home/node/code
WORKDIR /home/node/code
COPY package-lock.json package.json ./
RUN npm ci
COPY . .
EXPOSE 3000
# run the server
CMD ["node", "index.js"]