Line 18 creates a file named ! instead of defined LOCK_FILE

[mcans]

Line 18 in docker-entrypoint.sh --> echo "$(date +%s)" >! "${LOCK_FILE}"
! seems to be a typo. Resulting in creating a file called ! instead of the defined variable.

[pires]

It's not a typo and it's meant to overwrite the file even if it exist, regardless of the noclobber option.

However, I think it should be replaced with >|.