Add proper argument validation at the start of upgrade.sh:
- Check that exactly 4 arguments are provided
- Display a helpful usage message with argument descriptions
- Include a concrete example command
This prevents cryptic errors when the script is called incorrectly
and provides clear guidance on expected parameters. With set -u enabled,
accessing unset positional parameters would cause an unclear error message.
Enable bash strict mode in all shell scripts to catch errors early:
- set -e: Exit immediately if a command exits with non-zero status
- set -u: Treat unset variables as an error
- set -o pipefail: Return value of a pipeline is the status of the last
command to exit with non-zero status
This prevents silent failures and makes debugging easier by failing fast
when something goes wrong instead of continuing with potentially corrupted
state.
