--- List all Packages etc. - for ubuntu: dpkg -l | wc -l - for node:20-alpine: apk info | wc -l
`--system` Creates a system user (UID < 1000, no login shell, no password, used to run services)
--- Demo User `docker run -it --rm node:20-alpine sh` `cat /etc/passwd`
--- Secrets vs. Env Vars --- - secrets are mounted to `/run/secrets/<secret-name> - secrets as `env variables` are visible in `docker inspect`, secrets files are not -> more secure!
--- Bash History --- history -> list entries with line numbers history -d 99 -> delete entry number 99, effective after logout of current shell