Add Link header handling to ThermalSubsystem

Along with adding Link header, this commit updates ThermalSubsystem
to respond to HEAD requests. The link header is something required
by the Redfish spec.

Also, Removed redundant code[1]

[1] https://gerrit.openbmc.org/c/openbmc/bmcweb/+/58731/2/redfish-core/lib/thermal_subsystem.hpp#b48

Tested:
HEAD /redfish/v1/Chassis/<str>/ThermalSubsystem returns a correct
looking Link header.
Following that Link header resolves the schema file.

Get /redfish/v1/Chassis/BadChassis/ThermalSubsystem returns 404.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Ib93573808e4370ac45c2051517cd3f1c28e0f8bb

1 files changed, 35 insertions, 2 deletions

diff --git a/redfish-core/lib/thermal_subsystem.hpp b/redfish-core/lib/thermal_subsystem.hpp
index 390b294206..d86e3c30db 100644
--- a/redfish-core/lib/thermal_subsystem.hpp
+++ b/redfish-core/lib/thermal_subsystem.hpp
@@ -24,6 +24,10 @@ inline void doThermalSubsystemCollection(
         messages::resourceNotFound(asyncResp->res, "Chassis", chassisId);
         return;
     }
+
+    asyncResp->res.addHeader(
+        boost::beast::http::field::link,
+        "</redfish/v1/JsonSchemas/ThermalSubsystem/ThermalSubsystem.json>; rel=describedby");
     asyncResp->res.jsonValue["@odata.type"] =
         "#ThermalSubsystem.v1_0_0.ThermalSubsystem";
     asyncResp->res.jsonValue["Name"] = "Thermal Subsystem";
@@ -36,16 +40,40 @@ inline void doThermalSubsystemCollection(
     asyncResp->res.jsonValue["Status"]["Health"] = "OK";
 }
 
+inline void handleThermalSubsystemCollectionHead(
+    App& app, const crow::Request& req,
+    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
+    const std::string& chassisId)
+{
+    if (!redfish::setUpRedfishRoute(app, req, asyncResp))
+    {
+        return;
+    }
+
+    auto respHandler = [asyncResp, chassisId](
+                           const std::optional<std::string>& validChassisPath) {
+        if (!validChassisPath)
+        {
+            messages::resourceNotFound(asyncResp->res, "Chassis", chassisId);
+            return;
+        }
+        asyncResp->res.addHeader(
+            boost::beast::http::field::link,
+            "</redfish/v1/JsonSchemas/ThermalSubsystem/ThermalSubsystem.json>; rel=describedby");
+    };
+    redfish::chassis_utils::getValidChassisPath(asyncResp, chassisId,
+                                                std::bind_front(respHandler));
+}
+
 inline void handleThermalSubsystemCollectionGet(
     App& app, const crow::Request& req,
     const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
-    const std::string& param)
+    const std::string& chassisId)
 {
     if (!redfish::setUpRedfishRoute(app, req, asyncResp))
     {
         return;
     }
-    const std::string& chassisId = param;
 
     redfish::chassis_utils::getValidChassisPath(
         asyncResp, chassisId,
@@ -55,6 +83,11 @@ inline void handleThermalSubsystemCollectionGet(
 inline void requestRoutesThermalSubsystem(App& app)
 {
     BMCWEB_ROUTE(app, "/redfish/v1/Chassis/<str>/ThermalSubsystem/")
+        .privileges(redfish::privileges::headThermalSubsystem)
+        .methods(boost::beast::http::verb::head)(std::bind_front(
+            handleThermalSubsystemCollectionHead, std::ref(app)));
+
+    BMCWEB_ROUTE(app, "/redfish/v1/Chassis/<str>/ThermalSubsystem/")
         .privileges(redfish::privileges::getThermalSubsystem)
         .methods(boost::beast::http::verb::get)(std::bind_front(
             handleThermalSubsystemCollectionGet, std::ref(app)));