Problem

Currently the node user is created with useradd --uid 1000 --gid node --shell /bin/bash --create-home node.

When customizing the UID / GID using build args with groupmod -g "${GID}" node && usermod -u "${UID}" -g "${GID}" node, some folks are reporting they are running out of disk space and can't build the image when they have a non-1000 UID on systems that create a lot of users.

Here's a comment going into more detail: nickjj/docker-flask-example#7 (comment)

Also not using --no-log-init will cause Hadolint to throw this warning: -:44 DL3046 warning: useradd without flag -l and high UID will result in excessively large Image.

The usermod command doesn't support being able to set that option so it means our only option is to delete the node user and create a new one in which case life could be simplified by setting that flag here. You could make a case this is a bug report and not feature request due to the implications of not setting this flag when you create users in a Docker image.

Solution

Add --no-log-init to all of the useradd commands that create the node user.