Source MLZ config environment name and region from configuration file

[glennmusa]

Description

Generally, as much as possible, trying to source as much configuration from the MLZ configuration file instead of passing values by shell commands. This will make the automation more flexible for UI integration and CI/CD deployments.

• Rename enclave to mlz_env_name
• Source location from mlz_config_location

Issue reference

The issue this PR will close: #59

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles or validates correctly
• BASH scripts have been validated using shellcheck
• All tests pass (manual and automated)
• The documentation is updated to cover any new or changed features
• Markdown files have been linted using the recommended linter. (See .vscode/extensions.json.)
• Relevant issues are linked to this PR

[brooke-hamilton]

I made a couple of changes to the README. I have not finished executing the deployment. I stopped at setting values in saca-hub.tfvars because I don't know the answer to this question: What is deploymentname in saca-hub.tfvars?

deploymentname     = "{SACA_DEPLOYMENTNAME}"

[glennmusa]

@brooke-hamilton deployment name, at the scope you indicate, can be whatever you so choose, it's not generated by anything in these changes but is a terraform variable for replacement. The changes in this PR have no effect on what variable substitution happens at terraform execution time. That happens here, specifically:

missionlz/scripts/apply_terraform.sh

Lines 113 to 117 in 3617572

	terraform apply \
	-var-file="${globalvars}" \
	-var-file="${tfvars}" \
	-var "mlz_clientid=${client_id}" \
	-var "mlz_clientsecret=${client_secret}"

[brooke-hamilton]

@brooke-hamilton deployment name, at the scope you indicate, can be whatever you so choose, it's not generated by anything in these changes but is a terraform variable for replacement.

Is it the same as mlz_env_name in mlz_tf_cfg.var? Or is it a different variable, but it could be the same value?

[glennmusa]

@brooke-hamilton precisely. They're two different values. Could be the same, maybe (probably) they should be for ease of use, but they're not related today. A good rule of thumb is that if it's "MLZ" it's probably related to the customizations we're building. I'd wager 95% of the terraform in the repo is written with the assumption none of that exists (which it should).

The gap we're talking about here is that work we've been talking about collectively of "given a single configuration file, please generate all terraform variables" -- that doesn't exist today.