Use just the FQDN for ARM metadata host endpoints with Terraform

[glennmusa]

Benefit/Result/Outcome
Users deploying into an air-gapped cloud can run quickstart CLI deployments. Today they cannot.

Description
Today, when using the quickstart CLI deployment, we pass the output of az cloud show --query endpoints.resourceManager as the metadata host URI for initializing, applying, and destroying Terraform backends.

However, in some clouds, the HTTP URI is not permitted for this value and only the FQDN is allowed.

in an air-gapped cloud, this is not valid:

# not valid
terraform init \
  -backend-config "metadata_host=https://management.azure.com/"

but, in an air-gapped cloud, this is valid:

# valid
terraform init \
  -backend-config "metadata_host=management.azure.com"

the smallest way to do this is to check if mlz_metadatahost is the key name of the value we're printing to file and then to strip the HTTP-ness of the string then (and until the need arises to selectively trim strings of HTTP when building the .mlzconfig I don't think we need to build anything more complex than that):

missionlz/src/scripts/config/append_prereq_endpoints.sh

Lines 36 to 47 in 54f2f7b

	append_cloud_value() {
	local mlz_key_name=$1
	local cloud_key_name=$2
	local file=$3
	local cloud_key_value
	cloud_key_value=$(az cloud show --query "${cloud_key_name}" --output tsv)
	if [[ $cloud_key_value ]]; then
	printf "%s=%s\n" "${mlz_key_name}" "${cloud_key_value}" >> "${file}"
	fi
	}

Acceptance Criteria

• When generating an MLZ config file, strip the mlz_metadatahost value of URI identifiers leaving just the FQDN