Start node readonly ledger dir hygiene check (#7475)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: achamayou

CHANGELOG.md

@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [7.0.0-dev6]
+
+[7.0.0-dev6]: https://github.com/microsoft/CCF/releases/tag/ccf-7.0.0-dev6
+
+### Changed
+
+- Start nodes now confirm that read-only ledger directories are empty on startup (#7355).
+
 ## [7.0.0-dev5]
 
 [7.0.0-dev5]: https://github.com/microsoft/CCF/releases/tag/ccf-7.0.0-dev5

python/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "ccf"
-version = "7.0.0-dev5"
+version = "7.0.0-dev6"
 authors = [
   { name="CCF Team", email="CCF-Sec@microsoft.com" },
 ]

src/host/run.cpp

@@ -822,6 +822,21 @@ namespace ccf
         return static_cast<int>(CLI::ExitCodes::ValidationError);
       }
 
+      for (const auto& readonly_ledger_directory :
+           config.ledger.read_only_directories)
+      {
+        if (
+          files::exists(readonly_ledger_directory) &&
+          !fs::is_empty(readonly_ledger_directory))
+        {
+          LOG_FATAL_FMT(
+            "On start, read-only ledger directories should not exist or be "
+            "empty ({})",
+            readonly_ledger_directory);
+          return static_cast<int>(CLI::ExitCodes::ValidationError);
+        }
+      }
+
       populate_config_for_start(config, startup_config);
     }
     else if (config.command.type == StartType::Join)