Generate S3 config for mimir workers

src/charm.py

@@ -183,6 +183,8 @@ def _update_mimir_config(self) -> bool:
             logger.warning("cannot update mimir config: coordinator hasn't published one yet.")
             return False
 
+        # Data published by the coordinator won't have the actual common root data directory used by workers
+        # Update the configuration with data directory paths using the _set_data_dirs method
         config = self._set_data_dirs(mimir_config)
 
         if self._running_mimir_config() != config:
@@ -194,30 +196,47 @@ def _update_mimir_config(self) -> bool:
         return False
 
     def _set_data_dirs(self, config: Dict[str, Any]) -> dict:
-        """Set the data-dirs in the config we received from the coordinator.
+        """Set the data directories in the received config from the coordinator.
 
-        - Place all data dirs under a common root data dir, so files are persisted across upgrades.
-          Following the default names from official docs:
-          https://grafana.com/docs/mimir/latest/references/configuration-parameters/
+        - All data directories are placed under a common root data directory to persist
+        files across upgrades. The naming follows the default conventions from the
+        official Mimir docs: https://grafana.com/docs/mimir/latest/references/configuration-parameters/
         """
         config = config.copy()
-        for key, folder in (
-            ("alertmanager", "data-alertmanager"),
-            ("compactor", "data-compactor"),
-        ):
-            if key not in config:
-                config[key] = {}
-            config[key]["data_dir"] = str(self._root_data_dir / folder)
-
-        # blocks_storage:
-        #   bucket_store:
-        #     sync_dir: /etc/mimir/tsdb-sync
-        #   data_dir: /data/tsdb-sync
-        if config.get("blocks_storage"):
-            config["blocks_storage"] = {
-                "bucket_store": {"sync_dir": str(self._root_data_dir / "tsdb-sync")}
-            }
 
+        # Define a list of keys, subkeys, and folders in the Mimir config
+        # that need to be under the common root data directory
+        data_mapping = [
+            ("alertmanager", "data_dir", "data-alertmanager"),
+            ("alertmanager_storage", "filesystem", "data-alertmanager-recovery"),
+            ("compactor", "data_dir", "data-compactor"),
+            ("ruler", "rule_path", "data-ruler"),
+            ("ruler_storage", "filesystem", "ruler"),
+            ("blocks_storage", "filesystem", "blocks"),
+            ("blocks_storage", "tsdb", "tsdb"),
+            ("blocks_storage", "bucket_store", "tsdb-sync"),
+        ]
+
+        # The Mimir coordinator doesn't know the actual location of where the data
+        # will reside in the workers. The following loop updates the path of each key
+        # in the data_mapping list to match the actual common root data directory where
+        # the data will reside.
+        for key, subkey, folder in data_mapping:
+            # Ensure the key exists in the config dictionary
+            config.setdefault(key, {})
+
+            # Check if the subkey exists in the corresponding key's configuration
+            if subkey in config[key]:
+                # Update the subkey based on its type
+                # Both "data_dir" and "rule_path" in Mimir config don't have subkeys
+                if "data_dir" == subkey or subkey == "rule_path":
+                    config[key][subkey] = str(self._root_data_dir / folder)
+                # Both "filesystem" and "tsdb" in Mimir config have a subkey "dir"
+                elif "filesystem" == subkey or subkey == "tsdb":
+                    config[key][subkey] = {"dir": str(self._root_data_dir / folder)}
+                # "bucket_store" in Mimir config has a subkey "sync_dir"
+                elif "bucket_store" == subkey:
+                    config[key][subkey] = {"sync_dir": str(self._root_data_dir / folder)}
         return config
 
     def _running_mimir_config(self) -> Optional[dict]: