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How To Build a Node.js Application with Docker [Quickstart]

katjuell on February 17, 2020

Introduction This tutorial will walk you through creating an application image for a static website that uses the Express framework and ...

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Eugene Karataev • Mar 15 '20

Thanks for the great introduction to Docker!

If you follow the tutorial and like me have the error
Error response from daemon: Dockerfile parse error line 4: unknown instruction: /HOME/NODE/APP
during docker build, then replace lines 3,4 in Dockerfile with one line.

From

RUN mkdir -p /home/node/app/node_modules && chown -R node:node 
/home/node/app

RUN mkdir -p /home/node/app/node_modules && chown -R node:node /home/node/app

katjuell • Mar 15 '20

Looks like that was a formatting error in the markdown – should be fixed now. That instruction is definitely all one line. Thanks for catching!

Chris • Feb 20 '20

To keep the image as small as possible you can delete the cache npm builds

RUN npm install --production && npm cache clean --force

And by putting "fix" settings that don't change, like

EXPOSE 8080

towards the beginning of the Dockerfile you can sometimes save build time because docker can build upon existing layers that didn't change.

Gergely Polonkai • Feb 19 '20

If you can install podman, you no longer need a sudo account as podman can work without root access. It works just like docker, using the very same parameters. You can even alias docker=podman.

Also, why creating package.json by hand? npm init can create it for you so you wonʼt suffer from possible typos.