Unbound variable access breaks deployment

[alovett-kainos]

https://github.com/tfutils/tfscaffold/blame/d782a759c369d4aaab564338b5338cad3ede4e9a/bin/terraform.sh#L8

The enforcing of set -u in the terraform.sh script causes the script to fail, in the event that no additional parameters are passed to terraform.
Line 284: declare extra_args="${@} ${no_color}"; # All arguments supplied after "--" returns the following error:

bin/terraform.sh: line 284: @: unbound variable

This is because once all of our provided parameters are parsed, ${@} returns empty, in violation of the unbound variable setting.

The script does however pass if I include some dummy config, e.g. bin/terraform.sh --project myproj --region eu-west-2 --bootstrap --action plan -- -var="test=test"

[Zordrak]

Cross-reference: #50 is a separate but adjacent set -u regression.

This issue (#49) is the earlier crash — ${@} unbound at
bin/terraform.sh:284 when no -- arguments are
supplied. The workaround noted here (passing a dummy -- -var=...) gets past
line 284, but a --bootstrap run without -e/--environment then hits #50:
environment: unbound variable, because environment is never declared in the
bootstrap branch.

They share a cause class (enabling set -u in v2.3.0 exposed pre-existing
unguarded references) but have distinct root causes and distinct fixes. Keeping
them as separate issues; ideally addressed together as a single "complete the
set -u hardening" pass so bootstrap can be verified end-to-end.

[Zordrak]

Tracked under #53 — [Tracking] Complete the set -u hardening. See the tracker for the recommended unified fix ordering across all four set -u regressions.