Introduce embedded HTTP server for HAProxy monitoring dashboard

- Added a Python-based HTTP server to serve `dashboard.html` at `/` or `/dashboard.html` paths.
- Updated HAProxy configuration to integrate backend for the dashboard.
- Enhanced handling of index paths with conditional redirects to the dashboard page.
- Modified tests and updated expected outputs to reflect these changes.

src/easyhaproxy/main.py

@@ -2,6 +2,8 @@ import argparse
 import os
 import shutil
 import sys
+import threading
+from http.server import BaseHTTPRequestHandler, HTTPServer
 
 from deepdiff import DeepDiff
 
@@ -16,6 +18,38 @@ from functions import (
 from processor import ProcessorInterface
 
 
+class DashboardHandler(BaseHTTPRequestHandler):
+    _content: bytes | None = None
+
+    def do_GET(self):
+        if self.path in ("/", "/index.html", "/dashboard.html"):
+            if DashboardHandler._content is None:
+                dashboard_path = os.path.join(Consts.www_path, "dashboard.html")
+                try:
+                    with open(dashboard_path, "rb") as f:
+                        DashboardHandler._content = f.read()
+                except OSError:
+                    DashboardHandler._content = b""
+            self.send_response(200)
+            self.send_header("Content-Type", "text/html; charset=utf-8")
+            self.send_header("Content-Length", str(len(DashboardHandler._content)))
+            self.end_headers()
+            self.wfile.write(DashboardHandler._content)
+        else:
+            self.send_response(404)
+            self.end_headers()
+
+    def log_message(self, format, *args):
+        pass
+
+
+def start_dashboard_server():
+    server = HTTPServer(("127.0.0.1", Consts.DASHBOARD_SERVER_PORT), DashboardHandler)
+    t = threading.Thread(target=server.serve_forever, daemon=True)
+    t.start()
+    logger_easyhaproxy.info(f"Dashboard server listening on 127.0.0.1:{Consts.DASHBOARD_SERVER_PORT}")
+
+
 def _build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         prog="easy-haproxy",
@@ -146,6 +180,8 @@ def start():
     os.makedirs(Consts.certs_certbot, exist_ok=True)
     os.makedirs(Consts.certs_haproxy, exist_ok=True)
 
+    start_dashboard_server()
+
     processor_obj.save_config(Consts.haproxy_config)
     processor_obj.save_certs(Consts.certs_haproxy)
     certbot_certs_found = processor_obj.get_certbot_hosts()

src/easymapping/config_generator.py

@@ -4,7 +4,7 @@ import re
 
 from jinja2 import Environment, FileSystemLoader
 
-from functions import Functions, logger_easyhaproxy
+from functions import Functions, logger_easyhaproxy, Consts
 
 from .label_handler import DockerLabelHandler
 
@@ -92,7 +92,8 @@ class HaproxyConfigGenerator:
         return template.render(
             data=self.mapping,
             global_plugin_configs=self.global_plugin_configs,
-            defaults_plugin_configs=self.defaults_plugin_configs
+            defaults_plugin_configs=self.defaults_plugin_configs,
+            dashboard_server_port=Consts.DASHBOARD_SERVER_PORT
         )
 
     def parse(self, container_metadata):

src/functions/consts.py

@@ -56,4 +56,11 @@ class Consts:
     @classproperty
     def certs_haproxy(cls):
         """Path to user-provided certificates directory."""
-        return f"{cls.base_path}/certs/haproxy"
+        return f"{cls.base_path}/certs/haproxy"
+
+    @classproperty
+    def www_path(cls):
+        """Path to the web assets directory (dashboard, static files)."""
+        return f"{cls.base_path}/www"
+
+    DASHBOARD_SERVER_PORT = 9190

src/plugins/builtin/fastcgi.py

@@ -10,7 +10,7 @@ The plugin creates:
 
 Configuration:
     - enabled: Enable/disable the plugin (default: true)
-    - document_root: Document root path (default: /etc/easyhaproxy/www)
+    - document_root: Document root path (default: /var/www/html)
     - script_filename: Pattern for SCRIPT_FILENAME (default: %[path])
     - index_file: Default index file (default: index.php)
     - path_info: Enable PATH_INFO support (default: true)
@@ -39,8 +39,6 @@ Example Kubernetes Annotation:
 import os
 import sys
 
-from functions import Consts
-
 # Add parent directory to path for imports
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
@@ -52,7 +50,7 @@ class FastcgiPlugin(PluginInterface):
 
     def __init__(self):
         self.enabled = True
-        self.document_root = Consts.base_path + "/www"
+        self.document_root = "/var/www/html"
         self.script_filename = "%[path]"
         self.index_file = "index.php"
         self.path_info = True

src/templates/haproxy.cfg.j2

@@ -97,8 +97,14 @@ frontend dashboard
     mode http
     acl is_index path /
     acl is_index path /index.html
-    http-request return status 200 content-type "text/html" file /etc/easyhaproxy/www/dashboard.html if is_index
-    http-request return status 404
+    acl is_dashboard path /dashboard.html
+    http-request set-path /dashboard.html if is_index
+    http-request return status 404 if !is_dashboard
+    default_backend srv_dashboard
+
+backend srv_dashboard
+    mode http
+    server Local 127.0.0.1:{{ dashboard_server_port }}
 {% endif %}
 {% for o in data["easymapping"] -%}
     {% set mode = o["mode"] or "http" %}