Refactor initFromFbWhoAmI

Summary:
Currently we have a bit complicated logic to decide platform product name and fabricLocation by first comparing the network layers and then modelName, which is a bit overdone to me. The reason is we only need to set the fabric location for galaxy line card and all the rest platforms should have the same process.
Besides, there're 4 different places define fruid path, and they're using different location. Therefore, I decided to move the define in our "fboss/agent/platforms/wedge/WedgeProductInfo.cpp".

Differential Revision: D10209630

fbshipit-source-id: d55f637a8db9dd0fdac55eb8786f033eb49e7b5a

fboss/agent/platforms/wedge/WedgePlatformInit.cpp

@@ -18,10 +18,6 @@
 #include "fboss/agent/platforms/wedge/Wedge40Platform.h"
 #include "fboss/agent/platforms/wedge/Wedge100Platform.h"
 
-DEFINE_string(fruid_filepath,
-              "/var/facebook/fboss/fruid.json",
-              "File for storing the fruid data");
-
 namespace facebook { namespace fboss {
 
 std::unique_ptr<WedgePlatform> chooseWedgePlatform() {

fboss/agent/platforms/wedge/WedgeProductInfo.cpp

@@ -46,6 +46,9 @@ constexpr auto kFabricLocationRight = "RIGHT";
 
 DEFINE_string(mode, "",
               "The mode the FBOSS controller is running as, wedge, lc, or fc");
+DEFINE_string(fruid_filepath,
+              "/var/facebook/fboss/fruid.json",
+              "File for storing the fruid data");
 
 namespace facebook { namespace fboss {
 
@@ -64,7 +67,8 @@ void WedgeProductInfo::initialize() {
     folly::readFile(path_.str().c_str(), data);
     parse(data);
   } catch (const std::exception& err) {
-    XLOG(ERR) << err.what();
+    XLOG(ERR) << "Failed initializing WedgeProductInfo from " << path_
+              << ", fall back to use fbwhoami: " << err.what();
     // if fruid info fails fall back to fbwhoami
     initFromFbWhoAmI();
   }

fboss/agent/platforms/wedge/WedgeProductInfo.h

@@ -12,6 +12,8 @@
 #include "fboss/agent/if/gen-cpp2/ctrl_types.h"
 #include <folly/Range.h>
 
+DECLARE_string(fruid_filepath);
+
 namespace facebook { namespace fboss {
 
 enum class WedgePlatformMode {

fboss/qsfp_service/platforms/wedge/WedgeManagerInit.cpp

@@ -14,11 +14,6 @@
 #include "fboss/qsfp_service/platforms/wedge/Wedge40Manager.h"
 #include "fboss/qsfp_service/platforms/wedge/Wedge100Manager.h"
 
-DEFINE_string(
-    fruid_filepath,
-    "/dev/shm/fboss/fruid.json",
-    "File for storing the fruid data");
-
 namespace facebook { namespace fboss {
 
 std::unique_ptr<TransceiverManager> createTransceiverManager() {