MK8S-25: Address PR review comments - refactor and improve code quality

Address all review feedback from rdebay-scality:

1. Create INDEX_HTML_FILENAME constant to avoid typos in filename strings
2. Add _get_saltenv_directories() helper method to factorize repeated
   saltenv directory path creation logic
3. Improve comment clarity: "Actually remove the index.html files"
4. Use constant and helper method throughout clean/create/targets functions

Code improvements:
- Eliminate code duplication for saltenv path creation
- Single source of truth for index.html filename
- Cleaner, more maintainable code structure
- Better error prevention with constants instead of magic strings

Author: rdebay-scality

buildchain/buildchain/targets/repository.py

@@ -143,6 +143,7 @@ class RPMRepository(Repository):
     """A software repository for CentOS x86_64."""
 
     ARCH = "x86_64"
+    INDEX_HTML_FILENAME = "index.html"
 
     def __init__(
         self,
@@ -207,40 +208,55 @@ def clean() -> None:
             task["file_dep"].extend([self.get_rpm_path(pkg) for pkg in self.packages])
         return task
 
+    def _get_saltenv_directories(self) -> tuple:
+        """Get saltenv directory paths for scality repository.
+
+        Returns:
+            Tuple of (saltenv_dir, top_saltenv_dir) paths
+        """
+        if self.name != "scality":
+            return None, None
+
+        # Saltenv directory at repository level (cleaner for cleanup)
+        saltenv_dir = (
+            self._repo_root
+            / self._releasever
+            / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
+        )
+        # Top-level saltenv directory (needed for health check)
+        top_saltenv_dir = (
+            self._repo_root / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
+        )
+        return saltenv_dir, top_saltenv_dir
+
     def create_index_files(self) -> types.TaskDict:
         """Create index.html files for repository directories."""
 
         def clean() -> None:
             """Delete the index.html files created by this task."""
             # Clean repository-specific index files
             index_files = [
-                self.rootdir / "index.html",
-                self.rootdir / self.ARCH / "index.html",
+                self.rootdir / self.INDEX_HTML_FILENAME,
+                self.rootdir / self.ARCH / self.INDEX_HTML_FILENAME,
             ]
             # Clean shared directory index files if this is scality repo
-            if self.name == "scality":
-                # Saltenv directory at repository level (cleaner for cleanup)
-                saltenv_dir = (
-                    self._repo_root
-                    / self._releasever
-                    / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
-                )
-                # Top-level saltenv directory (needed for health check)
-                top_saltenv_dir = (
-                    self._repo_root
-                    / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
-                )
+            saltenv_dir, top_saltenv_dir = self._get_saltenv_directories()
+            if saltenv_dir and top_saltenv_dir:
                 index_files.extend(
                     [
                         # Repository-level saltenv structure
-                        saltenv_dir / "index.html",
-                        saltenv_dir / "redhat" / "index.html",
-                        saltenv_dir / "redhat" / str(self._releasever) / "index.html",
+                        saltenv_dir / self.INDEX_HTML_FILENAME,
+                        saltenv_dir / "redhat" / self.INDEX_HTML_FILENAME,
+                        saltenv_dir
+                        / "redhat"
+                        / str(self._releasever)
+                        / self.INDEX_HTML_FILENAME,
                         # Top-level saltenv (for health check)
-                        top_saltenv_dir / "index.html",
+                        top_saltenv_dir / self.INDEX_HTML_FILENAME,
                     ]
                 )
 
+            # Actually remove the index.html files
             for index_file in index_files:
                 if index_file.exists():
                     index_file.unlink()
@@ -254,18 +270,8 @@ def create_index() -> None:
 
             # Also create shared directory index files, but only from scality repo
             # to avoid doit task conflicts between multiple repositories
-            if self.name == "scality":
-                # Saltenv directory at repository level (cleaner for cleanup)
-                saltenv_dir = (
-                    self._repo_root
-                    / self._releasever
-                    / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
-                )
-                # Top-level saltenv directory (needed for health check)
-                top_saltenv_dir = (
-                    self._repo_root
-                    / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
-                )
+            saltenv_dir, top_saltenv_dir = self._get_saltenv_directories()
+            if saltenv_dir and top_saltenv_dir:
                 repository_directories.extend(
                     [
                         # Repository-level saltenv structure
@@ -280,35 +286,29 @@ def create_index() -> None:
             for repository_directory in repository_directories:
                 # Create directory if it doesn't exist, then create index.html
                 repository_directory.mkdir(parents=True, exist_ok=True)
-                index_file = repository_directory / "index.html"
+                index_file = repository_directory / self.INDEX_HTML_FILENAME
                 index_file.touch()
                 # Set readable permissions for nginx
                 index_file.chmod(0o644)
 
         # Build targets list - include shared directories only for scality repo
         targets = [
-            self.rootdir / "index.html",
-            self.rootdir / self.ARCH / "index.html",
+            self.rootdir / self.INDEX_HTML_FILENAME,
+            self.rootdir / self.ARCH / self.INDEX_HTML_FILENAME,
         ]
-        if self.name == "scality":
-            # Saltenv directory at repository level (cleaner for cleanup)
-            saltenv_dir = (
-                self._repo_root
-                / self._releasever
-                / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
-            )
-            # Top-level saltenv directory (needed for health check)
-            top_saltenv_dir = (
-                self._repo_root / f"{config.PROJECT_NAME.lower()}-{versions.VERSION}"
-            )
+        saltenv_dir, top_saltenv_dir = self._get_saltenv_directories()
+        if saltenv_dir and top_saltenv_dir:
             targets.extend(
                 [
                     # Repository-level saltenv structure
-                    saltenv_dir / "index.html",
-                    saltenv_dir / "redhat" / "index.html",
-                    saltenv_dir / "redhat" / str(self._releasever) / "index.html",
+                    saltenv_dir / self.INDEX_HTML_FILENAME,
+                    saltenv_dir / "redhat" / self.INDEX_HTML_FILENAME,
+                    saltenv_dir
+                    / "redhat"
+                    / str(self._releasever)
+                    / self.INDEX_HTML_FILENAME,
                     # Top-level saltenv (for health check)
-                    top_saltenv_dir / "index.html",
+                    top_saltenv_dir / self.INDEX_HTML_FILENAME,
                 ]
             )