Uses a dedicated setting to generate the magma VITE_CALDERA_URL variable

[jbaptperez]

Description

Fix proposal for issue #2984, using a dedicated setting to be properly transferred to the magma's .env file when using the --build option.

The setting name can be changed if needed.

Note the related issue is linked to a more general topic about configuration variables: Separating server listening settings, (HTTP) client and contact (agent) ones.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Locally tested.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

[djlawren]

Tested on remote host and localhost. All good from my perspective.

We are considering how to effectively document the login bug and mitigation going forward, but that shouldn't block these changes.

[behemothsecurity]

@djlawren We are deploying a caldera instance on EC2, trying to expose the GUI over the public IP - we ran into a lot of issues, which this MR should be fixing (we have a small similar patch which proves to be working). Could this please be merged asap, to facilitate other users and our deployment ?

[djlawren]

Opened corresponding documentation PRs: #3006, mitre/fieldmanual#126

@djlawren We are deploying a caldera instance on EC2, trying to expose the GUI over the public IP - we ran into a lot of issues, which this MR should be fixing (we have a small similar patch which proves to be working). Could this please be merged asap, to facilitate other users and our deployment ?

Noted on the urgency, apologies for the delays here. On to @elegantmoose now to review and merge.

[mkultraWasHere]

@prose-leviathan My bad.