tests(rpc): rpc mock/hook

KAG-5551

bin/busted

@@ -19,6 +19,9 @@ local cert_path do
     busted_cert_content = busted_cert_content .. "\n" .. pl_file.read(system_cert_path)
   end
 
+  local cluster_cert_content = assert(pl_file.read("spec/fixtures/kong_clustering.crt"))
+  busted_cert_content = busted_cert_content .. "\n" .. cluster_cert_content
+
   pl_file.write(busted_cert_file, busted_cert_content)
   cert_path = busted_cert_file
 end

spec/02-integration/01-helpers/05-rpc-mock_spec.lua

@@ -0,0 +1,146 @@
+local helpers = require("spec.helpers")
+local server = require("spec.helpers.rpc_mock.server")
+local client = require("spec.helpers.rpc_mock.client")
+local get_node_id = helpers.get_node_id
+
+local function trigger_change()
+  -- the initial sync is flaky. let's trigger a sync by creating a service
+  local admin_client = helpers.admin_client()
+  assert.res_status(201, admin_client:send {
+    method = "POST",
+    path = "/services/",
+    body = {
+      url = "http://example.com",
+    },
+    headers = {
+      ["Content-Type"] = "application/json",
+    },
+  })
+end
+
+describe("rpc mock/hook", function()
+  local recover
+  lazy_setup(function()
+    if not kong.worker_events then
+      helpers.patch_worker_events()
+      recover = true
+    end
+  end)
+
+  lazy_teardown(function()
+    if recover then
+      kong.worker_events = nil
+    end
+  end)
+
+  describe("server side", function()
+    local server_mock
+
+    lazy_setup(function()
+      helpers.get_db_utils()
+
+      server_mock = server.new()
+      assert(server_mock:start())
+
+      assert(helpers.start_kong({
+        database = "off",
+        role = "data_plane",
+        cluster_mtls = "shared",
+        cluster_cert = "spec/fixtures/kong_clustering.crt",
+        cluster_cert_key = "spec/fixtures/kong_clustering.key",
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+        cluster_rpc = "on",
+        cluster_rpc_sync = "on",
+        log_level = "debug",
+        cluster_control_plane = "127.0.0.1:8005",
+      }))
+    end)
+
+    lazy_teardown(function()
+      server_mock:stop(true)
+      helpers.stop_kong(nil, true)
+    end)
+
+    it("recording", function()
+      trigger_change()
+
+      local record = server_mock:wait_for_call()
+      assert.is_table(record.response.result.default.deltas)
+    end)
+
+    it("mock", function()
+      local client_version
+      server_mock:mock("kong.sync.v2.get_delta", function(node_id, payload)
+        client_version = payload.default.version
+        return { default = { version = 100, deltas = {} } }
+      end)
+      server_mock:attach_debugger()
+
+      local dp_id = get_node_id("servroot")
+
+      server_mock:wait_for_node(dp_id)
+
+      assert(server_mock:call(dp_id, "kong.sync.v2.notify_new_version", { default = { new_version = 100, } }))
+
+      -- the mock should have been called
+      helpers.wait_until(function()
+        return client_version
+      end, 20)
+    end)
+  end)
+
+  describe("client side", function()
+    local client_mock
+    local called = false
+
+    lazy_setup(function()
+      helpers.get_db_utils()
+
+      client_mock = assert(client.new())
+      assert(helpers.start_kong({
+        role = "control_plane",
+        cluster_mtls = "shared",
+        cluster_cert = "spec/fixtures/kong_clustering.crt",
+        cluster_cert_key = "spec/fixtures/kong_clustering.key",
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+        cluster_rpc = "on",
+        cluster_rpc_sync = "on",
+      }))
+
+      client_mock.callbacks:register("kong.sync.v2.notify_new_version", function(node_id, payload)
+        called = true
+      end)
+
+      client_mock:start()
+      client_mock:wait_until_connected()   
+    end)
+
+    lazy_teardown(function()
+      helpers.stop_kong(nil, true)
+      client_mock:stop()
+    end)
+
+    it("client->CP", function()
+      local res, err = client_mock:call("control_plane", "kong.sync.v2.get_delta", { default = { version = 0,},})
+      assert.is_nil(err)
+      assert.is_table(res and res.default and res.default.deltas)
+
+      local res, err = client_mock:call("control_plane", "kong.sync.v2.unknown", { default = { },})
+      assert.is_string(err)
+      assert.is_nil(res)
+    end)
+
+    it("CP->client", function()
+      -- this registers the data plane node
+      local res, err = client_mock:call("control_plane", "kong.sync.v2.get_delta", { default = { version = 0,},})
+      assert.is_nil(err)
+      assert.is_table(res and res.default and res.default.deltas)
+
+      trigger_change()
+
+      helpers.wait_until(function()
+        return called
+      end, 20)
+    end)
+  end)
+end)

spec/fixtures/custom_plugins/kong/plugins/rpc-debug/handler.lua

@@ -0,0 +1,76 @@
+local kong_meta = require("kong.meta")
+
+local _M = {
+  PRIORITY = 1000,
+  VERSION = kong_meta.version,
+}
+
+local original_callbacks = {}
+local inc_id = 0
+
+function _M.init_worker()
+  kong.rpc.callbacks:register("kong.rpc.debug.register", function(node_id, register_payload)
+    local proxy_apis = register_payload.proxy_apis
+
+    for _, proxy_api in ipairs(proxy_apis) do
+      -- unregister and save the original callback
+      local original_cb
+      if not original_callbacks[proxy_api] then
+        original_callbacks[proxy_api] = kong.rpc.callbacks.callbacks[proxy_api]
+      end
+      original_cb = original_callbacks[proxy_api]
+      kong.rpc.callbacks.callbacks[proxy_api] = nil
+
+      kong.log.info("hooking registering RPC proxy API: ", proxy_api)
+      kong.rpc.callbacks:register(proxy_api, function(client_id, payload)
+        local id = inc_id
+        inc_id = inc_id + 1
+        kong.log.info("hooked proxy API ", proxy_api, " called by node: ", client_id)
+        kong.log.info("forwarding to node: ", node_id)
+        local res, err = kong.rpc:call(node_id, "kong.rpc.debug.mock", { call_id = id, method = proxy_api, node_id = client_id, payload = payload })
+        if not res then
+          return nil, "Failed to proxy(" .. node_id .. "): " .. err
+        end
+
+        if res.error then
+          return nil, res.error
+        end
+
+        if res.prehook or res.posthook then
+          if res.prehook then
+            payload = res.args
+          end
+
+          local origin_res, origin_err = original_cb(client_id, payload)
+
+          if res.posthook then
+            res, err = kong.rpc:call(node_id, "kong.rpc.debug.posthook", { call_id = id, method = proxy_api, node_id = client_id, payload = {result = origin_res, error = origin_err} })
+            if not res then
+              return nil, "Failed to call post hook(" .. node_id .. "): " .. err
+            end
+
+            return res.result, res.error
+          end
+        elseif res.mock then
+          return res.result, res.error
+        end
+
+        return nil, "invalid response from proxy"
+      end)
+    end
+
+    return true
+  end)
+
+  kong.rpc.callbacks:register("kong.rpc.debug.call", function(node_id, payload)
+    local res, err = kong.rpc:call(payload.node_id, payload.method, payload.args)
+    return res, err
+  end)
+
+  kong.rpc.callbacks:register("kong.rpc.debug.lua_code", function(node_id, payload)
+    local code = assert(loadstring(payload))
+    return code()
+  end)
+end
+
+return _M

spec/fixtures/custom_plugins/kong/plugins/rpc-debug/schema.lua

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

spec/helpers.lua

@@ -28,6 +28,8 @@ local server = reload_module("spec.internal.server")
 local client = reload_module("spec.internal.client")
 local wait = reload_module("spec.internal.wait")
 
+-- redo the patches to apply the kong global patches
+misc.repatch_timer()
 
 ----------------
 -- Variables/constants
@@ -226,4 +228,9 @@ local wait = reload_module("spec.internal.wait")
   make_temp_dir = misc.make_temp_dir,
 
   build_go_plugins = cmd.build_go_plugins,
+
+  get_node_id = misc.get_node_id,
+
+  repatch_timer = misc.repatch_timer,
+  patch_worker_events = misc.patch_worker_events,
 }

spec/helpers/rpc_mock/client.lua

@@ -0,0 +1,68 @@
+-- by importing helpers, we ensure the kong PDK module is initialized
+local helpers = require "spec.helpers"
+local rpc_mgr = require("kong.clustering.rpc.manager")
+local default_cert = require("spec.helpers.rpc_mock.default").default_cert
+local uuid = require "kong.tools.uuid"
+
+
+local _M = {}
+
+
+local default_dp_conf = {
+  role = "data_plane",
+  cluster_control_plane = "localhost:8005",
+}
+
+setmetatable(default_dp_conf, { __index = default_cert })
+local default_meta = { __index = default_dp_conf, }
+
+
+local function do_nothing() end
+
+
+local function client_stop(rpc_mgr)
+  -- a hacky way to stop rpc_mgr from reconnecting
+  rpc_mgr.try_connect = do_nothing
+
+  -- this will stop all connections
+  for _, socket in pairs(rpc_mgr.clients) do
+    for conn in pairs(socket) do
+      pcall(conn.stop, conn)
+    end
+  end
+end
+
+
+local function client_is_connected(rpc_mgr)
+  for _, socket in pairs(rpc_mgr.clients) do
+    if next(socket) then
+      return true
+    end
+  end
+  return false
+end
+
+
+local function client_wait_until_connected(rpc_mgr, timeout)
+  return helpers.wait_until(function()
+    return rpc_mgr:is_connected()
+  end, timeout or 15)
+end
+
+
+-- TODO: let client not emits logs as it's expected to fail to connect for the first few seconds
+function _M.new(opts)
+  opts = opts or {}
+  setmetatable(opts, default_meta)
+  local ret = rpc_mgr.new(default_dp_conf, opts.name or uuid.uuid())
+
+  ret.stop = client_stop
+  ret.is_connected = client_is_connected
+  ret.start = ret.try_connect
+  ret.wait_until_connected = client_wait_until_connected
+
+  return ret
+end
+
+
+return _M

spec/helpers/rpc_mock/default.lua

@@ -0,0 +1,10 @@
+local default_cert = {
+  cluster_mtls = "shared",
+  cluster_cert = "spec/fixtures/kong_clustering.crt",
+  cluster_cert_key = "spec/fixtures/kong_clustering.key",
+  nginx_conf = "spec/fixtures/custom_nginx.template",
+}
+
+return {
+  default_cert = default_cert,
+}