Merge pull request #3400 from canonical/handle-amend-errors

Handle failure to convert to QCOW2 v3

Author: Chris Townsend

src/platform/backends/qemu/qemu_virtual_machine.cpp

@@ -194,6 +194,19 @@ auto generate_metadata(const QStringList& platform_args, const QStringList& proc
     metadata[mount_data_key] = mount_args_to_json(mount_args);
     return metadata;
 }
+
+void convert_to_qcow2_v3_if_necessary(const mp::Path& image_path, const std::string& vm_name)
+{
+    try
+    {
+        // convert existing VMs to v3 too (doesn't affect images that are already v3)
+        mp::backend::amend_to_qcow2_v3(image_path);
+    }
+    catch (const mp::backend::QemuImgException& e)
+    {
+        mpl::log(mpl::Level::error, vm_name, e.what());
+    }
+}
 } // namespace
 
 mp::QemuVirtualMachine::QemuVirtualMachine(const VirtualMachineDescription& desc,
@@ -211,8 +224,8 @@ mp::QemuVirtualMachine::QemuVirtualMachine(const VirtualMachineDescription& desc
       monitor{&monitor},
       mount_args{mount_args_from_json(monitor.retrieve_metadata_for(vm_name))}
 {
-    // convert existing VMs to v3 too (doesn't affect images that are already v3)
-    mp::backend::amend_to_qcow2_v3(desc.image.image_path); // TODO drop in a couple of releases (going in on v1.13)
+    convert_to_qcow2_v3_if_necessary(desc.image.image_path,
+                                     vm_name); // TODO drop in a couple of releases (went in on v1.13)
 
     QObject::connect(
         this, &QemuVirtualMachine::on_delete_memory_snapshot, this,

src/platform/backends/shared/qemu_img_utils/qemu_img_utils.cpp

@@ -41,10 +41,10 @@ auto mp::backend::checked_exec_qemu_img(std::unique_ptr<mp::QemuImgProcessSpec>
     auto process_state = timeout ? process->execute(*timeout) : process->execute();
     if (!process_state.completed_successfully())
     {
-        throw std::runtime_error(fmt::format("{}: qemu-img failed ({}) with output:\n{}",
-                                             custom_error_prefix,
-                                             process_state.failure_message(),
-                                             process->read_all_standard_error()));
+        throw QemuImgException{fmt::format("{}: qemu-img failed ({}) with output:\n{}",
+                                           custom_error_prefix,
+                                           process_state.failure_message(),
+                                           process->read_all_standard_error())};
     }
 
     return process;
@@ -90,7 +90,8 @@ mp::Path mp::backend::convert_to_qcow_if_necessary(const mp::Path& image_path)
 void mp::backend::amend_to_qcow2_v3(const mp::Path& image_path)
 {
     checked_exec_qemu_img(
-        std::make_unique<mp::QemuImgProcessSpec>(QStringList{"amend", "-o", "compat=1.1", image_path}, image_path));
+        std::make_unique<mp::QemuImgProcessSpec>(QStringList{"amend", "-o", "compat=1.1", image_path}, image_path),
+        "Failed to amend image to QCOW2 v3");
 }
 
 bool mp::backend::instance_image_has_snapshot(const mp::Path& image_path, QString snapshot_tag)

src/platform/backends/shared/qemu_img_utils/qemu_img_utils.h

@@ -30,6 +30,12 @@ class QemuImgProcessSpec;
 
 namespace backend
 {
+class QemuImgException : public std::runtime_error
+{
+public:
+    using std::runtime_error::runtime_error;
+};
+
 Process::UPtr checked_exec_qemu_img(std::unique_ptr<QemuImgProcessSpec> spec,
                                     const std::string& custom_error_prefix = "Internal error",
                                     std::optional<int> timeout = std::nullopt);

tests/qemu/test_qemu_backend.cpp

@@ -19,6 +19,7 @@
 
 #include "tests/common.h"
 #include "tests/mock_environment_helpers.h"
+#include "tests/mock_logger.h"
 #include "tests/mock_process_factory.h"
 #include "tests/mock_status_monitor.h"
 #include "tests/stub_process_factory.h"
@@ -675,6 +676,29 @@ TEST_F(QemuBackend, ssh_hostname_timeout_throws_and_sets_unknown_state)
     EXPECT_EQ(machine.state, mp::VirtualMachine::State::unknown);
 }
 
+TEST_F(QemuBackend, logsErrorOnFailureToConvertToQcow2V3UponConstruction)
+{
+    mpt::StubVMStatusMonitor stub_monitor{};
+    NiceMock<mpt::MockQemuPlatform> mock_qemu_platform{};
+
+    process_factory->register_callback([this](mpt::MockProcess* process) {
+        if (process->program().contains("qemu-img") && process->arguments().contains("compat=1.1"))
+        {
+            mp::ProcessState exit_state{};
+            exit_state.exit_code = 1;
+            ON_CALL(*process, execute).WillByDefault(Return(exit_state));
+        }
+        else
+            return handle_external_process_calls(process);
+    });
+
+    auto logger_scope = mpt::MockLogger::inject();
+    logger_scope.mock_logger->screen_logs(mpl::Level::error);
+    logger_scope.mock_logger->expect_log(mpl::Level::error, "Failed to amend image to QCOW2 v3");
+
+    mp::QemuVirtualMachine machine{default_description, &mock_qemu_platform, stub_monitor, instance_dir.path()};
+}
+
 TEST_F(QemuBackend, lists_no_networks)
 {
     EXPECT_CALL(*mock_qemu_platform_factory, make_qemu_platform(_)).WillOnce([this](auto...) {