Add VyOS API support for /configure and /config-file save

[mikehansen1970]

Summary

Add support for additional VyOS API operations required for NAT persistence workaround:

• /configure endpoint: set and delete operations
• /config-file endpoint: save operation

Changes in https_server_api.uc

1. Added save operation to /config-file endpoint (lines 32-44)

• Allows saving running configuration to /config/config.boot
• No payload needed (just op: "save")
• Required for persisting NAT rules across VyOS reboots

2. Added /configure endpoint support (lines 66-79)

• Supports set and delete operations
• Requires path array parameter
• set operation optionally accepts value parameter
• Auto-commits changes (no explicit commit needed)

Technical Notes

• /configure endpoint only supports set/delete operations (not commit/save)
• Commit happens automatically after each operation
• Save must use /config-file endpoint with op: "save"

Use Case

These operations are required for the NAT persistence workaround where we:

1. Delete old NAT rules: /configure delete nat source
2. Apply new rules: /configure set nat source rule X ...
3. Save to config.boot: /config-file save

This ensures NAT rules use the correct bridge interface (br0) and persist across VyOS reboots.

Related PRs

This change is required by the companion PR in the olg-ucentral-schema repository that implements the NAT persistence fix.

Testing

Tested on MinisForum MS-01 with VyOS VM:

• ✅ /configure set successfully creates NAT rules
• ✅ /configure delete successfully removes NAT rules
• ✅ /config-file save successfully persists to config.boot
• ✅ Changes survive VyOS reboots

[NavneetBarwal-RA]

These changes are not as per the initial design(retrieve + load) and apply a unified configuration each time from ucentral-client to Vyos .
Explanation is already provided in Telecominfraproject/olg-ucentral-schema#5 (comment)