zen hub command (#877)

- Feature: Added `zen hub` command for managing a hub server and its provisioned module instances:
  - `zen hub up` - Start a hub server (equivalent to `zen up` in hub mode)
  - `zen hub down` - Shut down a hub server
  - `zen hub provision <moduleid>` - Provision a storage server instance for a module
  - `zen hub deprovision <moduleid>` - Deprovision a storage server instance
  - `zen hub hibernate <moduleid>` - Hibernate a provisioned instance (shut down, data preserved)
  - `zen hub wake <moduleid>` - Wake a hibernated instance
  - `zen hub status [moduleid]` - Show state of all instances or a specific module
- Feature: Added new hub HTTP endpoints for instance lifecycle management:
  - `POST /hub/modules/{moduleid}/hibernate` - Hibernate the instance for the given module
  - `POST /hub/modules/{moduleid}/wake` - Wake a hibernated instance for the given module
- Improvement: `zen up` refactored to use shared `StartupZenServer`/`ShutdownZenServer` helpers (also used by `zen hub up`/`zen hub down`)
- Bugfix: Fixed shutdown event not being cleared after the server process exits in `ZenServerInstance::Shutdown()`, which could cause stale state on reuse

1 files changed, 11 insertions, 12 deletions

diff --git a/src/zenserver/hub/storageserverinstance.cpp b/src/zenserver/hub/storageserverinstance.cpp
index bab501429..7933cfa70 100644
--- a/src/zenserver/hub/storageserverinstance.cpp
+++ b/src/zenserver/hub/storageserverinstance.cpp
@@ -123,7 +123,7 @@ StorageServerInstance::DeprovisionLocked()
 	m_State = HubInstanceState::Unprovisioned;
 }
 
-void
+bool
 StorageServerInstance::HibernateLocked()
 {
 	// Signal server to shut down, but keep data around for later wake
@@ -133,16 +133,13 @@ StorageServerInstance::HibernateLocked()
 		ZEN_WARN("Attempted to hibernate storage server instance for module '{}' which is not provisioned (state: '{}')",
 				 m_ModuleId,
 				 ToString(m_State.load()));
-		return;
+		return false;
 	}
 
 	if (!m_ServerInstance.IsRunning())
 	{
 		ZEN_WARN("Attempted to hibernate storage server instance for module '{}' which is not running", m_ModuleId);
-
-		// This is an unexpected state. Should consider the instance invalid?
-
-		return;
+		return false;
 	}
 
 	m_State = HubInstanceState::Hibernating;
@@ -150,12 +147,13 @@ StorageServerInstance::HibernateLocked()
 	{
 		m_ServerInstance.Shutdown();
 		m_State = HubInstanceState::Hibernated;
-		return;
+		return true;
 	}
 	catch (const std::exception& Ex)
 	{
 		ZEN_ERROR("Failed to hibernate storage server instance for module '{}': {}", m_ModuleId, Ex.what());
 		m_State = HubInstanceState::Provisioned;  // Shutdown failed; instance is still running
+		return false;
 	}
 }
 
@@ -166,9 +164,10 @@ StorageServerInstance::WakeLocked()
 
 	if (m_State.load() != HubInstanceState::Hibernated)
 	{
-		ZEN_WARN("Attempted to wake storage server instance for module '{}' which is not hibernated", m_ModuleId);
-
-		return true;  // Instance is already usable (noop success)
+		ZEN_WARN("Attempted to wake storage server instance for module '{}' which is not hibernated (state: '{}')",
+				 m_ModuleId,
+				 ToString(m_State.load()));
+		return false;
 	}
 
 	ZEN_ASSERT_FORMAT(!m_ServerInstance.IsRunning(), "Storage server instance for module '{}' is already running", m_ModuleId);
@@ -389,11 +388,11 @@ StorageServerInstance::ExclusiveLockedPtr::Deprovision()
 	m_Instance->DeprovisionLocked();
 }
 
-void
+bool
 StorageServerInstance::ExclusiveLockedPtr::Hibernate()
 {
 	ZEN_ASSERT(m_Instance != nullptr);
-	m_Instance->HibernateLocked();
+	return m_Instance->HibernateLocked();
 }
 
 bool