fix(gateway): aggregate component /logs and /bulk-data from hosted apps' fqns

[bburda]

Summary

Fix two handlers that silently returned empty results for synthetic / runtime-discovered components, by mirroring the AREA / FUNCTION aggregation pattern already present in the same files.

• LogHandlers::handle_get_logs - the COMPONENT branch fed entity.fqn to LogManager::get_logs(..., prefix_match=true). Synthetic components have an empty fqn, so the prefix match selected nothing and the response was an empty items list even when the component grouped N active apps. Resolve hosted apps via cache.get_apps_for_component() and call get_logs(host_fqns, prefix_match=false). Manifest deployments with a non-empty fqn and no hosted apps fall through to the original namespace-prefix path. Response now also carries x-medkit.aggregation_level=component, app_count, and aggregation_sources for parity with AREA and FUNCTION.
• BulkDataHandlers::get_source_filters - identical pattern. The handler had a FUNCTION-only aggregation arm and fell through to entity.fqn / entity.namespace_path for COMPONENT. Both empty for synthetic components, so source filters were {}, descriptor lists came back empty, and ownership checks in handle_download short-circuited. Extended the aggregation arm to handle COMPONENT identically; manifest-only components still fall through to the namespace prefix path.
• docs/api/rest.rst updated to describe the actual aggregation behavior for /components/{id}/logs instead of the stale namespace prefix match wording.

Tests

• New integration test test_component_get_logs_aggregates_child_apps in test_logging_api.test.py verifies a synthetic component returns non-empty items plus the new aggregation metadata. Asserts len(items) > 0 directly because the original bug returned 0 items with otherwise valid x-medkit metadata, so checking app_count alone is not sufficient. Matches aggregation_sources by FQN substring instead of bare app id.
• New integration test test_bulk_data_component_aggregates_child_apps in test_bulk_data_api.test.py verifies the equivalent fix for the bulk-data endpoint.

SOVD API impact

• No changes to SOVD-defined request paths, response schemas, or error codes.
• Additive x-medkit extensions on /components/{id}/logs only - new optional aggregation_level, aggregated, app_count, aggregation_sources fields, emitted only when local aggregation is active. Existing clients that ignore unknown x-medkit.* fields are unaffected. /components/{id}/bulk-data/rosbags payload schema is unchanged.

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Issue

• closes [BUG] Synthetic components return empty results from /logs and /bulk-data resource collections #393

A related but distinct symptom on handle_get_fault for synthetic components is a scope-leak that needs a different fix (changing the GetFault service contract), tracked separately - see comment on #380.

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Type

• Bug fix
• New feature or tests (two new integration tests + x-medkit aggregation metadata on /components/{id}/logs)
• Breaking change
• Documentation only (docs/api/rest.rst log endpoints description)

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Testing

All local runs green:

• ./scripts/test.sh unit --packages-select ros2_medkit_gateway - 2099 assertions across 81 tests, 0 failures.
• ./scripts/test.sh test_logging_api --packages-select ros2_medkit_integration_tests - 22 logging tests + shutdown, 0 failures. Includes the new test_component_get_logs_aggregates_child_apps.
• ./scripts/test.sh test_bulk_data_api --packages-select ros2_medkit_integration_tests - 10 tests, 0 failures. Includes the new test_bulk_data_component_aggregates_child_apps.
• ./scripts/test.sh lint --packages-select ros2_medkit_gateway ros2_medkit_integration_tests - clean (clang-format, cmake-lint, ament-copyright, flake8, pep257, cppcheck, xmllint).
• pre-push clang-tidy on changed files - clean.

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Checklist

• Breaking changes are clearly described (there are none; only additive x-medkit extensions on /components/{id}/logs)
• Tests were added or updated if needed
• Docs were updated if behavior or public API changed

[Copilot]

Pull request overview

Fixes empty results for synthetic/runtime-discovered components on /logs and /bulk-data/rosbags by aggregating from hosted apps’ effective FQNs (matching existing AREA/FUNCTION aggregation behavior) and updates docs/tests accordingly.

Changes:

• Update LogHandlers::handle_get_logs to aggregate component logs from hosted apps and emit component-level aggregation metadata.
• Update BulkDataHandlers::get_source_filters to aggregate component bulk-data sources from hosted apps with manifest fallback behavior.
• Add integration tests for component aggregation behavior and update REST API documentation for component logs aggregation.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/ros2_medkit_gateway/src/http/handlers/log_handlers.cpp	Aggregate component logs from hosted apps’ FQNs + add x-medkit aggregation metadata.
src/ros2_medkit_gateway/src/http/handlers/bulkdata_handlers.cpp	Extend hosted-app aggregation to component source filters with fallback behavior.
src/ros2_medkit_integration_tests/test/features/test_logging_api.test.py	Add integration test validating non-empty aggregated component logs + metadata.
src/ros2_medkit_integration_tests/test/features/test_bulk_data_api.test.py	Add integration test validating aggregated component bulk-data descriptors.
docs/api/rest.rst	Document component logs aggregation and fallback behavior.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/ros2_medkit_gateway/test/test_handler_context.cpp:57

• json is used throughout this test file (e.g., json::parse(...)) but the using json = nlohmann::json; alias was removed and there is no replacement alias/namespace import. This will not compile. Re-introduce the alias (or fully-qualify nlohmann::json) in this file.

using namespace ros2_medkit_gateway;
using namespace ros2_medkit_gateway::handlers;

// =============================================================================
// HandlerContext static method tests (don't require GatewayNode)
// =============================================================================

TEST(HandlerContextStaticTest, SendErrorSetsStatusAndBody) {
  httplib::Response res;

  HandlerContext::send_error(res, 400, ERR_INVALID_REQUEST, "Test error message");

  EXPECT_EQ(res.status, 400);
  EXPECT_EQ(res.get_header_value("Content-Type"), "application/json");

  auto body = json::parse(res.body);
  EXPECT_EQ(body["error_code"], ERR_INVALID_REQUEST);
  EXPECT_EQ(body["message"], "Test error message");

[Copilot]

get_source_filters() was moved into the public section specifically for unit testing, but this header is under include/ and is likely installed/exported. Exposing this internal helper expands the public API surface and makes future refactors harder. Prefer keeping it private and granting test access via FRIEND_TEST(...), or extracting the branching logic into a separate testable helper (e.g., a free function in a detail namespace) without changing the handler's public interface.

[bburda]

Done. Moved get_source_filters back to private and extracted the entity-type branching to handlers::detail::compute_bulkdata_source_filters (a free function in a detail namespace, declared at the bottom of bulkdata_handlers.hpp). The instance method is now a one-line wrapper that fetches the cache from ctx_ and delegates. Tests target the free function directly with a bare ThreadSafeEntityCache - no BulkDataHandlers instance, no GatewayNode, no DDS context required.

[Copilot]

This code uses std::make_move_iterator(...) but the file doesn't include <iterator>. Relying on indirect includes is non-portable and can break builds with different standard library implementations. Add #include <iterator> (or avoid make_move_iterator here).

[bburda]

Done. Added #include <iterator> to log_handlers.cpp.