CODEWITHSUNDEEP
dockerdockerfile
JJ F
JJ F

Reputation: 1549

Files mysteriously missing in docker image

I create the following image:

FROM node:14.7.0-alpine3.12
COPY ./test.txt /home/node/app/

using this command:

docker build . -t my-test

The image builds successfully, I run it like this:

docker run -it my-test

I inspect the content of the folder /home/node/app using SSH.

So far all good. I push the image to my docker registry. I download the image, I run it and do the same operation. ALL GOOD. I can see the file test.txt is there as expected.

I try the same in other machines, it all works good. However, in some machines, I do the same operation but the file test.txt is just not there. I double check the hashes, the image is correct, but the file is not in the image.

What's wrong?!

Upvotes: 4

Views: 4472

Answers (1)

Yerke
Yerke

Reputation: 2235

If you're mounting a volume over an existing directory you will lose the original content of your image.

In your case it might be happening because a folder is mounted in one of the levels of the path /home/node/app.

Use docker inspect <container> to monitor the list of mounted volumes inside of your container ("Mounts" fields). You can also extract to output only Mounts using:
docker inspect -f '{{ .Mounts }}' <container>

Upvotes: 7

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