From c79e2bef7dea5289111a961dcd0185e0ae5dd499 Mon Sep 17 00:00:00 2001
From: xumin <xumin.zhou@konghq.com>
Date: Tue, 17 Dec 2024 17:18:30 +0800
Subject: [PATCH] tests(rpc): rpc mock/hook

---
 spec/01-unit/19-hybrid/04-rpc_spec.lua        |  68 +++++++
 .../kong/plugins/rpc-proxy/handler.lua        |  59 ++++++
 .../kong/plugins/rpc-proxy/schema.lua         |  12 ++
 spec/helpers.lua                              |  20 ++
 spec/helpers/rpc_mock/client.lua              |  58 ++++++
 spec/helpers/rpc_mock/default.lua             |   8 +
 spec/helpers/rpc_mock/server.lua              | 187 ++++++++++++++++++
 7 files changed, 412 insertions(+)
 create mode 100644 spec/01-unit/19-hybrid/04-rpc_spec.lua
 create mode 100644 spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/handler.lua
 create mode 100644 spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/schema.lua
 create mode 100644 spec/helpers/rpc_mock/client.lua
 create mode 100644 spec/helpers/rpc_mock/default.lua
 create mode 100644 spec/helpers/rpc_mock/server.lua

diff --git a/spec/01-unit/19-hybrid/04-rpc_spec.lua b/spec/01-unit/19-hybrid/04-rpc_spec.lua
new file mode 100644
index 000000000000..938f881f07f2
--- /dev/null
+++ b/spec/01-unit/19-hybrid/04-rpc_spec.lua
@@ -0,0 +1,68 @@
+-- by importing helpers, we initialize the kong PDK module
+local helpers = require "spec.helpers"
+local server = require("spec.helpers.rpc_mock.server")
+local client = require("spec.helpers.rpc_mock.client")
+
+describe("rpc v2", function()
+  describe("full sync pagination", function()
+    describe("server side", function()
+      local server_mock
+      local port
+      lazy_setup(function()
+        server_mock = server.new()
+        assert(server_mock:start())
+        port = server_mock.listen
+
+        helpers.start_kong({
+          role = "data_plane",
+          cluster_cert = "spec/fixtures/kong_spec.crt",
+          cluster_cert_key = "spec/fixtures/kong_spec.key",
+          cluster_rpc = "on",
+          cluster_rpc_listen = "localhost:" .. port,
+          cluster_incremental_sync = "on",
+        })
+      end)
+      lazy_teardown(function()
+        server_mock:stop(true)
+
+        helpers.stop_kong(nil, true)
+      end)
+
+      it("works", function()
+        helpers.wait_until(function()
+          return server_mock.records and next(server_mock.records)
+        end,20)
+      end)
+    end)
+    
+    describe("client side", function()
+      local client_mock
+      lazy_setup(function()
+        client_mock = assert(client.new())
+        helpers.start_kong({
+          role = "control_plane",
+          cluster_cert = "spec/fixtures/kong_spec.crt",
+          cluster_cert_key = "spec/fixtures/kong_spec.key",
+          cluster_rpc = "on",
+          cluster_incremental_sync = "on",
+        })
+        client_mock:start()        
+      end)
+      lazy_teardown(function()
+        helpers.stop_kong(nil, true)
+        client_mock:stop()
+      end)
+
+      it("works", function()
+        client_mock:wait_until_connected()
+        
+        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)
+      end)
+    end)
+  end)
+end)
diff --git a/spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/handler.lua b/spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/handler.lua
new file mode 100644
index 000000000000..6d893cbd4213
--- /dev/null
+++ b/spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/handler.lua
@@ -0,0 +1,59 @@
+local rpc_mgr = require("kong.clustering.rpc.manager")
+local kong_meta = require("kong.meta")
+
+local _M = {
+  PRIORITY = 1000,
+  VERSION = kong_meta.version,
+}
+
+local original_callbacks = {}
+
+function _M.init_worker()
+  kong.rpc.callbacks:register("kong.rpc.proxy.register", function(node_id, register_payload)
+    local proxy_apis = register_payload.proxy_apis
+
+    for _, proxy_api in ipairs(proxy_apis) do
+      kong.log.info("Hook registering RPC proxy API: ", proxy_api)
+      local original = kong.rpc.callbacks[proxy_api]
+      if original and not original_callbacks[proxy_api] then
+        original_callbacks[proxy_api] = original
+      end
+      kong.rpc.callbacks[proxy_api] = nil
+      kong.rpc.callbacks:register(proxy_api, function(client_id, payload)
+        local res, err = kong.rpc:call(node_id, "kong.rpc.proxy", { 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(client_id, payload)
+
+          if res.posthook then
+            res, err = kong.rpc:call(node_id, "kong.rpc.proxy.posthook", { 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)
+end
+
+return _M
diff --git a/spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/schema.lua b/spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/schema.lua
new file mode 100644
index 000000000000..41eb85a06209
--- /dev/null
+++ b/spec/fixtures/custom_plugins/kong/plugins/rpc-proxy/schema.lua
@@ -0,0 +1,12 @@
+return {
+  name = "rpc-proxy",
+  fields = {
+    {
+      config = {
+        type = "record",
+        fields = {
+        },
+      },
+    },
+  },
+}
diff --git a/spec/helpers.lua b/spec/helpers.lua
index 22b67c4434d3..c41854e8bf26 100644
--- a/spec/helpers.lua
+++ b/spec/helpers.lua
@@ -28,6 +28,26 @@ 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
+local _timerng
+
+_timerng = require("resty.timerng").new({
+  min_threads = 16,
+  max_threads = 32,
+})
+
+_timerng:start()
+
+_G.timerng = _timerng
+
+_G.ngx.timer.at = function (delay, callback, ...)
+  return _timerng:at(delay, callback, ...)
+end
+
+_G.ngx.timer.every = function (interval, callback, ...)
+  return _timerng:every(interval, callback, ...)
+end
+
 
 ----------------
 -- Variables/constants
diff --git a/spec/helpers/rpc_mock/client.lua b/spec/helpers/rpc_mock/client.lua
new file mode 100644
index 000000000000..669058861760
--- /dev/null
+++ b/spec/helpers/rpc_mock/client.lua
@@ -0,0 +1,58 @@
+-- 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 _M = {}
+local _MT = { __index = _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
+      conn:stop()
+    end
+  end
+end
+
+local function client_is_connected(rpc_mgr)
+  for _, socket in pairs(rpc_mgr.clients) do
+    for conn in pairs(socket) do
+      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 "dp")
+  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
diff --git a/spec/helpers/rpc_mock/default.lua b/spec/helpers/rpc_mock/default.lua
new file mode 100644
index 000000000000..8890e0d77bc8
--- /dev/null
+++ b/spec/helpers/rpc_mock/default.lua
@@ -0,0 +1,8 @@
+local default_cert = {
+  cluster_cert = "spec/fixtures/kong_spec.crt",
+  cluster_cert_key = "spec/fixtures/kong_spec.key",
+}
+
+return {
+  default_cert = default_cert,
+}
diff --git a/spec/helpers/rpc_mock/server.lua b/spec/helpers/rpc_mock/server.lua
new file mode 100644
index 000000000000..a613a58f0e62
--- /dev/null
+++ b/spec/helpers/rpc_mock/server.lua
@@ -0,0 +1,187 @@
+local helpers = require("spec.helpers")
+local client = require("spec.helpers.rpc_mock.client")
+local default_cert = require("spec.helpers.rpc_mock.default").default_cert
+
+local _M = {}
+local _MT = { __index = _M, }
+
+function _M.new(opts)
+  opts = opts or {}
+  opts.prefix = opts.prefix or "servroot_rpc_tap"
+  opts.role = "control_plane"
+  opts.plugins = "bundled,rpc-proxy"
+  opts.listen = opts.listen or 8005
+  opts.cluster_listen = opts.cluster_listen or ("0.0.0.0:" .. opts.listen)
+  opts.mocks = opts.mocks or {}
+  opts.prehooks = opts.prehooks or {}
+  opts.posthooks = opts.posthooks or {}
+  opts.cluster_rpc = "on"
+  opts.cluster_incremental_sync = opts.cluster_incremental_sync or "on"
+  if opts.interception == nil then
+    opts.interception = true
+  end
+
+  for k, v in pairs(default_cert) do
+    if opts[k] == nil then
+      opts[k] = v
+    end
+  end
+
+  return setmetatable(opts, _MT)
+end
+
+function _M.start(self)
+  local bp, db = helpers.get_db_utils(strategy, nil, { "rpc-proxy" })
+
+  local plugin = db.plugins:insert({
+    name = "rpc-proxy",
+    config = {},
+  })
+
+  assert(helpers.start_kong(self))
+
+  self.proxy_client = client.new({
+    cluster_control_plane = self.cluster_listen,
+  })
+
+  if self.interception then
+    self:enable_inception()
+  end
+
+  self.proxy_client.callbacks:register("kong.rpc.proxy.mock", function(proxy_id, proxy_payload)
+    local method, node_id, payload = proxy_payload.method, proxy_payload.node_id, proxy_payload.payload
+    local cb = self.mocks[method]
+    if cb then
+      local res, err = cb(node_id, payload, proxy_id, self)
+      return {
+        mock = true,
+        result = res,
+        error = err,
+      }
+    end
+
+    local prehook = self.prehooks[method] or self.prehooks["*"]
+    local posthook = self.posthooks[method] or self.posthooks["*"]
+    local result = {
+      prehook = prehook and true,
+      posthook = posthook and true,
+    }
+
+    if prehook then
+      local res, err = prehook(node_id, payload, proxy_id, self, method)
+      if not res then
+        return nil, err
+      end
+
+      result.args = res
+    end
+
+    return result
+  end)
+
+  self.proxy_client.callbacks:register("kong.rpc.proxy.posthook", function(proxy_id, proxy_payload)
+    local method, node_id, payload = proxy_payload.method, proxy_payload.node_id, proxy_payload.payload
+    local cb = self.posthooks[method] or self.posthooks["*"]
+    if not cb then
+      return nil, "no callback registered for method: " .. method
+    end
+
+    return cb(node_id, payload, proxy_id, self, method)
+  end)
+
+  self = setmetatable(self, _MT)
+
+  self.proxy_client:start()
+  self.proxy_client:wait_until_connected()
+
+  if next(self.mocks) or next(self.prehooks) or next(self.posthooks) then
+    return self:register_proxy()
+  end
+
+  return true
+end
+
+function _M:register_proxy()
+  local hooked = {}
+  for api_name, cb in pairs(self.mocks) do
+    hooked[api_name] = true
+  end
+  for api_name, cb in pairs(self.prehooks) do
+    hooked[api_name] = true
+  end
+  for api_name, cb in pairs(self.posthooks) do
+    hooked[api_name] = true
+  end
+  local hooked_list
+
+  if hooked["*"] then
+    hooked_list = self.proxy_client.client_capabilities.control_plane.list
+  else
+    hooked_list = {}
+    for api_name in pairs(hooked) do
+      hooked_list[#hooked_list + 1] = api_name
+    end
+  end
+
+  return self.proxy_client:call("control_plane", "kong.rpc.proxy.register", {
+    proxy_apis = hooked_list,
+  })
+end
+
+function _M:mock_api(api_name, cb)
+  self.mocks[api_name] = cb
+end
+
+function _M:prehook_api(api_name, cb)
+  self.prehooks[api_name] = cb
+end
+
+function _M:posthook_api(api_name, cb)
+  self.posthooks[api_name] = cb
+end
+
+local function get_records(server)
+  local records = server.records
+  if not records then
+    records = {}
+    server.records = records
+  end
+  return records
+end
+
+-- TODO: add req ID for correlation
+local function default_inception_prehook(node_id, payload, proxy_id, server, method)
+  local records = get_records(server)
+  records[#records + 1] = {
+    request = true,
+    node_id = node_id,
+    payload = payload,
+    proxy_id = proxy_id,
+    method = method,
+  }
+  return payload
+end
+
+local function default_inception_posthook(node_id, payload, proxy_id, server, method)
+  local records = get_records(server)
+  records[#records + 1] = {
+    response = true,
+    node_id = node_id,
+    payload = payload,
+    proxy_id = proxy_id,
+    method = method,
+  }
+  return payload
+end
+
+function _M:enable_inception()
+  self.prehooks["*"] = default_inception_prehook
+  self.posthooks["*"] = default_inception_posthook
+end
+
+function _M:stop(...)
+  helpers.stop_kong(self.prefix, ...)
+  self.proxy_client:stop()
+end
+
+return _M