[Testing] Refactor mock server to support distributed configuration loading (#37695) (#37713)

* Refactor mock server to support distributed configuration loading

Refactors the mock server implementation to support loading configuration from
multiple JSON files, enabling flexible mocking of different services during
Matter device commissioning validation.

Key Changes:
- Restructured configuration loading to support directory-based routing configs
- Added dataclass-based type safety for configuration and route definitions
- Updated path handling to use pathlib.Path for better cross-platform support
- Modified server launch configuration to support routing config directory
- Added configurations for mocking multiple services:
  * Distributed Compliance Ledger (DCL)
  * Product Terms & Conditions server

Technical Improvements:
- Introduced strongly typed Route and Configuration classes
- Simplified route matching logic with dedicated matcher
- Improved error handling for configuration loading
- Updated unit tests to support new configuration structure

The changes enable quick iteration of mock service responses during preproduction
testing and PlugFest validation, particularly for testing new commissioning
flows that rely on DCL-based configuration with indirect product server
references.

Test Configuration:
- Added example configurations for VID:65521/65522, PID:32769
- Updated TC URL endpoints to use port 44538
- Included sample Terms & Conditions responses

* server: Add validation checks for SSL certificate and key files

Add input validation to verify that SSL certificate and key files exist
and are regular files before attempting to create the SSL context.
This provides clearer error messages to users when certificate files
are missing or invalid, following the same validation pattern used for
config files.

Author: swan-amazon

.github/.wordlist.txt

@@ -326,6 +326,7 @@ CurrentHue
 CurrentLevel
 CurrentSaturation
 customAcl
+customizable
 customizations
 cvfJ
 cxx
@@ -1039,6 +1040,7 @@ otatesting
 otaURL
 OTBR
 otcli
+OU
 outform
 outgoingCommands
 overridable
@@ -1150,6 +1152,7 @@ PyObject
 pypi
 PyRun
 pytest
+PYTHONPATH
 QEMU
 Qorvo
 QPG
@@ -1326,6 +1329,7 @@ SRP
 SRV
 SSBL
 SSID
+SSL
 startoffset
 StartScan
 startsWith
@@ -1490,6 +1494,7 @@ unfocus
 Unicast
 UniFlash
 UnitLocalization
+unittest
 unpair
 unprovisioned
 Unsecure

.vscode/launch.json

@@ -4,12 +4,37 @@
     // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
     "version": "0.2.0",
     "configurations": [
+        {
+            "name": "Python: Mock Server Tests",
+            "type": "debugpy",
+            "request": "launch",
+            "module": "unittest",
+            "args": [
+                "${workspaceFolder}/integrations/mock_server/tests/test_mock_server.py"
+            ],
+            "env": {
+                "PYTHONPATH": "${workspaceFolder}/integrations/mock_server/src:${PYTHONPATH}"
+            },
+            "console": "integratedTerminal",
+            "cwd": "${workspaceFolder}"
+        },
         {
             "name": "Python Debugger: test_dcl_server",
             "type": "debugpy",
             "request": "launch",
-            "program": "/workspace/connectedhomeip/examples/chip-tool/commands/dcl/test_dcl_server.py",
-            "args": [],
+            "program": "${workspaceFolder}/integrations/mock_server/src/main.py",
+            "args": [
+                "--port",
+                "8443",
+                "--config",
+                "${workspaceFolder}/integrations/mock_server/configurations/server_config.json",
+                "--routing-config-dir",
+                "${workspaceFolder}/integrations/mock_server/configurations/fake_distributed_compliance_ledger",
+                "--cert",
+                "${workspaceFolder}/server.crt",
+                "--key",
+                "${workspaceFolder}/server.key"
+            ],
             "console": "integratedTerminal"
         },
         {

examples/chip-tool/commands/dcl/test_dcl_server.py

@@ -0,0 +1,56 @@
+# Mock HTTP/HTTPS Server
+
+## Overview
+
+This project provides a configurable mock HTTP/HTTPS server designed for API
+testing, dynamic response generation, and automated request handling. It
+supports static responses, dynamic custom response handlers, query parameter
+matching, request body validation (including regex), and both HTTP and HTTPS
+protocols.
+
+## Setup
+
+```bash
+openssl req -x509 -newkey rsa:2048 -keyout server.key -out server.crt -days 365 -nodes -subj "/C=US/ST= /L= /O= /OU= /CN=localhost"
+```
+
+## Features
+
+### Server Functionality
+
+-   Secure HTTPS with TLS support
+-   CLI-driven execution with customizable options (port, configuration files,
+    SSL options)
+-   Handles GET, POST, PUT, and DELETE requests
+-   Concurrent request handling via threading
+
+### Route Matching
+
+-   Exact path and wildcard (\*) path matching
+-   Query parameter validation
+-   Priority-based route matching
+
+### Configuration
+
+-   Main server configuration file
+-   Separate routing configuration directory
+-   JSON-based configuration format
+-   Dynamic route loading
+
+### Security & Logging
+
+-   TLS encryption (HTTPS only)
+-   Structured logging with DEBUG level
+-   Graceful error handling for invalid routes
+
+## Running Tests
+
+### Test Execution
+
+You can run the tests using one of these methods:
+
+1. Using Python unittest with PYTHONPATH:
+
+```bash
+PYTHONPATH=$PYTHONPATH:/workspace/connectedhomeip/integrations/mock_server/src python3 -m unittest integrations/mock_server/tests/test_mock_server.py
+```