Add metabase and write_cache operations

Signed-off-by: Andrey Berezin <a.berezin@yadro.com>

src/frostfs_testlib/storage/cluster.py

@@ -73,6 +73,21 @@ class ClusterNode:
     def s3_gate(self) -> S3Gate:
         return self.service(S3Gate)
 
+    def get_config(self, config_file_path: str) -> dict:
+        shell = self.host.get_shell()
+
+        result = shell.exec(f"cat {config_file_path}")
+        config_text = result.stdout
+
+        config = yaml.safe_load(config_text)
+        return config
+
+    def save_config(self, new_config: dict, config_file_path: str) -> None:
+        shell = self.host.get_shell()
+
+        config_str = yaml.dump(new_config)
+        shell.exec(f"echo '{config_str}' | sudo tee {config_file_path}")
+
     def service(self, service_type: type[ServiceClass]) -> ServiceClass:
         """
         Get a service cluster node of specified type.