What this snippet does
Files copied before USER stay owned by root, so the unprivileged user cannot write there.
Expected output
mkdir: can't create directory '/app/cache': Permission denied
Why practise typing this
Typing users & security code builds muscle memory for the symbols and indentation Docker uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More Docker practice
- Dropping rootUsers & Security · intermediate
- Creating a service accountUsers & Security · intermediate
- Read-only root filesystemUsers & Security · advanced
- Dropping capabilitiesUsers & Security · advanced
- Privileged containersUsers & Security · advanced
- Blocking privilege escalationUsers & Security · advanced