tests(clustering/rpc): add cases for rpc error handler

kong/clustering/rpc/socket.lua

@@ -195,6 +195,17 @@ function _M:process_rpc_msg(payload, collection)
     end
 
   else
+    -- may be some error message for peer
+    if not payload_id then
+      if payload.error then
+        ngx_log(ngx.ERR, "[rpc] RPC failed, code: ",
+                         payload.error.code, ", err: ",
+                         payload.error.message)
+      end
+
+      return true
+    end
+
     -- response, don't care about `collection`
     local interest_cb = self.interest[payload_id]
     self.interest[payload_id] = nil -- edge trigger only once
@@ -271,6 +282,16 @@ function _M:start()
 
       local payload = decompress_payload(data)
 
+      if not payload then
+        local res, err = self:push_response(
+                          new_error(nil, jsonrpc.PARSE_ERROR))
+        if not res then
+          return nil, err
+        end
+
+        goto continue
+      end
+
       -- single rpc call
       if not isarray(payload) then
         local ok, err = self:process_rpc_msg(payload)

spec/02-integration/18-hybrid_rpc/02-error_spec.lua

@@ -0,0 +1,68 @@
+local helpers = require "spec.helpers"
+
+
+-- register a test rpc service in custom plugin rpc-error-test
+for _, strategy in helpers.each_strategy() do
+  describe("Hybrid Mode RPC #" .. strategy, function()
+
+    lazy_setup(function()
+      helpers.get_db_utils(strategy, {
+        "clustering_data_planes",
+      }) -- runs migrations
+
+      assert(helpers.start_kong({
+        role = "control_plane",
+        cluster_cert = "spec/fixtures/kong_clustering.crt",
+        cluster_cert_key = "spec/fixtures/kong_clustering.key",
+        database = strategy,
+        cluster_listen = "127.0.0.1:9005",
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+        plugins = "bundled,rpc-error-test",
+        nginx_worker_processes = 4, -- multiple workers
+        cluster_rpc = "on", -- enable rpc
+        cluster_rpc_sync = "off", -- disable rpc sync
+      }))
+
+      assert(helpers.start_kong({
+        role = "data_plane",
+        database = "off",
+        prefix = "servroot2",
+        cluster_cert = "spec/fixtures/kong_clustering.crt",
+        cluster_cert_key = "spec/fixtures/kong_clustering.key",
+        cluster_control_plane = "127.0.0.1:9005",
+        proxy_listen = "0.0.0.0:9002",
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+        plugins = "bundled,rpc-error-test",
+        nginx_worker_processes = 4, -- multiple workers
+        cluster_rpc = "on", -- enable rpc
+        cluster_rpc_sync = "off", -- disable rpc sync
+      }))
+    end)
+
+    lazy_teardown(function()
+      helpers.stop_kong("servroot2")
+      helpers.stop_kong()
+    end)
+
+    describe("rpc errors", function()
+      it("in custom plugin", function()
+        local name = "servroot2/logs/error.log"
+
+        -- dp logs
+        assert.logfile(name).has.line(
+          "test #1 ok", true, 10)
+
+        -- dp logs
+        assert.logfile(name).has.line(
+          "[rpc] RPC failed, code: -32600, err: empty batch array", true, 10)
+        assert.logfile(name).has.line(
+          "[rpc] RPC failed, code: -32600, err: not a valid object", true, 10)
+        assert.logfile(name).has.line(
+          "test #2 ok", true, 10)
+
+        assert.logfile(name).has.no.line(
+          "assertion failed", true, 0)
+      end)
+    end)
+  end)
+end -- for _, strategy

spec/fixtures/custom_plugins/kong/plugins/rpc-error-test/handler.lua

@@ -0,0 +1,59 @@
+local cjson = require("cjson")
+
+
+local RpcErrorTestHandler = {
+  VERSION = "1.0",
+  PRIORITY = 1000,
+}
+
+
+function RpcErrorTestHandler:init_worker()
+  kong.rpc.callbacks:register("kong.test.exception", function(node_id)
+    return nil  -- no error message, default jsonrpc.SERVER_ERROR
+  end)
+
+  kong.rpc.callbacks:register("kong.test.error", function(node_id)
+    return nil, "kong.test.error"
+  end)
+
+  local worker_events = assert(kong.worker_events)
+  local node_id = "control_plane"
+
+  -- if rpc is ready we will start to call
+  worker_events.register(function(capabilities_list)
+    local res, err = kong.rpc:call(node_id, "kong.test.not_exist")
+    assert(not res)
+    assert(err == "Method not found")
+
+    local res, err = kong.rpc:call(node_id, "kong.test.exception")
+    assert(not res)
+    assert(err == "Server error")
+
+    local res, err = kong.rpc:call(node_id, "kong.test.error")
+    assert(not res)
+    assert(err == "kong.test.error")
+
+    ngx.log(ngx.DEBUG, "test #1 ok")
+
+  end, "clustering:jsonrpc", "connected")
+
+  -- if rpc is ready we will start to send raw msg
+  worker_events.register(function(capabilities_list)
+    local s = next(kong.rpc.clients[node_id])
+
+    -- send an empty array
+    local msg = setmetatable({}, cjson.array_mt)
+    assert(s:push_request(msg))
+
+    -- send an invalid msg
+    local msg = setmetatable({"invalid_request"}, cjson.array_mt)
+    assert(s:push_request(msg))
+
+    ngx.log(ngx.DEBUG, "test #2 ok")
+
+  end, "clustering:jsonrpc", "connected")
+
+end
+
+
+return RpcErrorTestHandler

spec/fixtures/custom_plugins/kong/plugins/rpc-error-test/schema.lua

@@ -0,0 +1,12 @@
+return {
+  name = "rpc-error-test",
+  fields = {
+    {
+      config = {
+        type = "record",
+        fields = {
+        },
+      },
+    },
+  },
+}