refactor(clustreing/rpc): constant for json rpc version (#13902)

https://konghq.atlassian.net/browse/KAG-5870

kong/clustering/rpc/concentrator.lua

@@ -116,7 +116,7 @@ function _M:_event_loop(lconn)
       if n.channel == rpc_resp_channel_name then
         -- an response for a previous RPC call we asked for
         local payload = cjson_decode(n.payload)
-        assert(payload.jsonrpc == "2.0")
+        assert(payload.jsonrpc == jsonrpc.VERSION)
 
         -- response
         local cb = self.interest[payload.id]
@@ -158,7 +158,7 @@ function _M:_event_loop(lconn)
           if res then
             -- call success
             res, err = self:_enqueue_rpc_response(reply_to, {
-              jsonrpc = "2.0",
+              jsonrpc = jsonrpc.VERSION,
               id = payload.id,
               result = res,
             })
@@ -169,7 +169,7 @@ function _M:_event_loop(lconn)
           else
             -- call failure
             res, err = self:_enqueue_rpc_response(reply_to, {
-              jsonrpc = "2.0",
+              jsonrpc = jsonrpc.VERSION,
               id = payload.id,
               error = {
                 code = jsonrpc.SERVER_ERROR,
@@ -292,7 +292,7 @@ function _M:call(node_id, method, params, callback)
   self.interest[id] = callback
 
   return self:_enqueue_rpc_request(node_id, {
-    jsonrpc = "2.0",
+    jsonrpc = jsonrpc.VERSION,
     method = method,
     params = params,
     id = id,

kong/clustering/rpc/future.lua

@@ -3,6 +3,7 @@ local _MT = { __index = _M, }
 
 
 local semaphore = require("ngx.semaphore")
+local jsonrpc = require("kong.clustering.rpc.json_rpc_v2")
 
 
 local STATE_NEW = 1
@@ -34,7 +35,7 @@ function _M:start()
   self.state = STATE_IN_PROGRESS
 
   local callback = function(resp)
-    assert(resp.jsonrpc == "2.0")
+    assert(resp.jsonrpc == jsonrpc.VERSION)
 
     if resp.result then
       -- succeeded

kong/clustering/rpc/json_rpc_v2.lua

@@ -9,6 +9,8 @@ local _M = {
   INVALID_PARAMS = -32602,
   INTERNAL_ERROR = -32603,
   SERVER_ERROR = -32000,
+
+  VERSION = "2.0",
 }
 
 
@@ -40,7 +42,7 @@ function _M.new_error(id, code, msg)
   end
 
   return {
-    jsonrpc = "2.0",
+    jsonrpc = _M.VERSION,
     id = id,
     error = {
       code = code,

kong/clustering/rpc/manager.lua

@@ -7,6 +7,7 @@ local client = require("resty.websocket.client")
 local socket = require("kong.clustering.rpc.socket")
 local future = require("kong.clustering.rpc.future")
 local utils = require("kong.clustering.rpc.utils")
+local jsonrpc = require("kong.clustering.rpc.json_rpc_v2")
 local callbacks = require("kong.clustering.rpc.callbacks")
 local clustering_tls = require("kong.clustering.tls")
 local constants = require("kong.constants")
@@ -154,7 +155,7 @@ function _M:_handle_meta_call(c)
   end
 
   local payload = cjson_decode(data)
-  assert(payload.jsonrpc == "2.0")
+  assert(payload.jsonrpc == jsonrpc.VERSION)
 
   if payload.method ~= RPC_MATA_V1 .. ".hello" then
     return nil, "wrong RPC meta call: " .. tostring(payload.method)
@@ -181,7 +182,7 @@ function _M:_handle_meta_call(c)
   assert(type(info.kong_conf) == "table")
 
   local payload = {
-    jsonrpc = "2.0",
+    jsonrpc = jsonrpc.VERSION,
     result = {
       rpc_capabilities = self.callbacks:get_capabilities_list(),
       -- now we only support snappy
@@ -232,7 +233,7 @@ function _M:_meta_call(c, meta_cap, node_id)
   }
 
   local payload = {
-    jsonrpc = "2.0",
+    jsonrpc = jsonrpc.VERSION,
     method = meta_cap .. ".hello",
     params = { info },
     id = 1,
@@ -253,7 +254,7 @@ function _M:_meta_call(c, meta_cap, node_id)
   end
 
   local payload = cjson_decode(data)
-  assert(payload.jsonrpc == "2.0")
+  assert(payload.jsonrpc == jsonrpc.VERSION)
 
   -- now we only support snappy
   if payload.result.rpc_frame_encoding ~= RPC_SNAPPY_FRAMED then

kong/clustering/rpc/socket.lua

@@ -79,7 +79,7 @@ function _M._dispatch(premature, self, cb, payload)
 
   -- success
   res, err = self.outgoing:push({
-    jsonrpc = "2.0",
+    jsonrpc = jsonrpc.VERSION,
     id = payload.id,
     result = res,
   })
@@ -143,7 +143,7 @@ function _M:start()
       assert(typ == "binary")
 
       local payload = decompress_payload(data)
-      assert(payload.jsonrpc == "2.0")
+      assert(payload.jsonrpc == jsonrpc.VERSION)
 
       if payload.method then
         -- invoke
@@ -276,7 +276,7 @@ function _M:call(node_id, method, params, callback)
   self.interest[id] = callback
 
   return self.outgoing:push({
-    jsonrpc = "2.0",
+    jsonrpc = jsonrpc.VERSION,
     method = method,
     params = params,
     id = id,