CODEWITHSUNDEEP
docker
sudharsan tk
sudharsan tk

Reputation: 504

Docker run and volume clarification

Below is my dockerfile, I do a copy of js file in copy command and set working directory after that,followed by volume and run command.Below is my dockerfile 1) I understand node_modules(Which is created because of running npm install) IS getting wipedoff when container is first initialized because of create volume in the same location My quesion why my app.js which i copied in step 3 is not getting wiped of since its also on the same path as volume?

FROM node:latest

ENV NODE_ENV=production
ENV PORT=3000

COPY . /app
WORKDIR /app
VOLUME ["/app"]


RUN npm install

EXPOSE $PORT

ENTRYPOINT ["node","app.js"]

Upvotes: 1

Views: 59

Answers (1)

Samuel Toh
Samuel Toh

Reputation: 19328

Q: Why is my app.js (which i copied in step 3) is not getting wiped off while node_modules is.

A: As explained in docker's documentation under the volume section.

Quote:

Changing the volume from within the Dockerfile:

If any build steps change the data within the volume after it has been declared, those changes will be discarded.

Reference: https://docs.docker.com/engine/reference/builder/#notes-about-specifying-volumes

Upvotes: 1

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