MK8S-25: Create empty index.html files for repository directories

Instead of changing the health check URL, create empty index.html files
in repository directories to prevent 403 errors while keeping autoindex
disabled for security.

This maintains the original health check functionality while preventing
directory structure exposure.

Author: rdebay-scality

buildchain/buildchain/targets/repository.py

@@ -206,6 +206,55 @@ def clean() -> None:
             task["file_dep"].extend([self.get_rpm_path(pkg) for pkg in self.packages])
         return task
 
+    def create_index_files(self) -> types.TaskDict:
+        """Create index.html files for repository directories."""
+
+        def create_index() -> None:
+            """Create empty index.html files in repository directories."""
+            saltenv_dir = self._repo_root / self._releasever
+            directories = [
+                saltenv_dir,  # /{saltenv}/
+                saltenv_dir / "redhat",  # /{saltenv}/redhat/
+                saltenv_dir / "redhat" / str(self._releasever),  # /{saltenv}/redhat/{os_ver}/
+                self.rootdir,  # Repository root
+                self.rootdir / self.ARCH,  # Architecture directory
+            ]
+            
+            for directory in directories:
+                if directory.exists():
+                    (directory / "index.html").touch()
+
+        saltenv_dir = self._repo_root / self._releasever
+        task = self.basic_task
+        task.update(
+            {
+                "name": self._get_task_name("create_index_files"),
+                "actions": [create_index],
+                "doc": f"Create index.html files for {self.name} repository directories.",
+                "title": utils.title_with_target1("CREATE INDEX FILES"),
+                "targets": [
+                    saltenv_dir / "index.html",
+                    saltenv_dir / "redhat" / "index.html",
+                    saltenv_dir / "redhat" / str(self._releasever) / "index.html",
+                    self.rootdir / "index.html",
+                    self.rootdir / self.ARCH / "index.html",
+                ],
+                "uptodate": [True],
+                "verbosity": 0,
+                "task_dep": [self._get_task_name("build_repodata", with_basename=True)],
+            }
+        )
+        return task
+
+    @property
+    def execution_plan(self) -> List[types.TaskDict]:
+        """Override execution plan to include index.html file creation."""
+        tasks = [self.build_repo()]
+        if self._packages:
+            tasks.extend(self.build_packages())
+        tasks.append(self.create_index_files())
+        return tasks
+
     def build_packages(self) -> List[types.TaskDict]:
         """Build the RPMs from SRPMs."""
         tasks = [self._mkdir_repo_root(), self._mkdir_repo_arch()]