feat: call destroy method when Nginx exits (apache#7866)

apisix/init.lua

@@ -152,6 +152,9 @@ end
 
 
 function _M.http_exit_worker()
+    -- TODO: we can support stream plugin later - currently there is not `destory` method
+    -- in stream plugins
+    plugin.exit_worker()
     require("apisix.plugins.ext-plugin.init").exit_worker()
 end
 

apisix/plugin.lua

@@ -356,6 +356,24 @@ function _M.load(config)
 end
 
 
+function _M.exit_worker()
+    for name, plugin in pairs(local_plugins_hash) do
+        local ty = PLUGIN_TYPE_HTTP
+        if plugin.type == "wasm" then
+            ty = PLUGIN_TYPE_HTTP_WASM
+        end
+        unload_plugin(name, ty)
+    end
+
+    -- we need to load stream plugin so that we can check their schemas in
+    -- Admin API. Maybe we can avoid calling `load` in this case? So that
+    -- we don't need to call `destroy` too
+    for name in pairs(stream_local_plugins_hash) do
+        unload_plugin(name, PLUGIN_TYPE_STREAM)
+    end
+end
+
+
 local function trace_plugins_info_for_debug(ctx, plugins)
     if not enable_debug() then
         return

docs/en/latest/plugin-develop.md

@@ -90,7 +90,7 @@ nginx_config:
 ```
 
 The plugin itself provides the init method. It is convenient for plugins to perform some initialization after
-the plugin is loaded.
+the plugin is loaded. If you need to clean up the initialization, you can put it in the corresponding destroy method.
 
 Note : if the dependency of some plugin needs to be initialized when Nginx start, you may need to add logic to the initialization
 method "http_init" in the file __apisix/init.lua__, and you may need to add some processing on generated part of Nginx

docs/zh/latest/plugin-develop.md

@@ -86,7 +86,7 @@ nginx_config:
         lua_shared_dict introspection        10m; # cache for JWT verification results
 ```
 
-插件本身提供了 init 方法。方便插件加载后做初始化动作。
+插件本身提供了 init 方法。方便插件加载后做初始化动作。如果你需要清理初始化动作创建出来的内容，你可以在对应的 destroy 方法里完成这一操作。
 
 注：如果部分插件的功能实现，需要在 Nginx 初始化启动，则可能需要在 __apisix/init.lua__ 文件的初始化方法 http_init 中添加逻辑，并且可能需要在 __apisix/cli/ngx_tpl.lua__ 文件中，对 Nginx 配置文件生成的部分，添加一些你需要的处理。但是这样容易对全局产生影响，根据现有的插件机制，**我们不建议这样做，除非你已经对代码完全掌握**。
 

t/node/plugin.t

@@ -0,0 +1,48 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+use t::APISIX 'no_plan';
+
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if (!$block->request) {
+        $block->set_value("request", "GET /t");
+    }
+
+    if ((!defined $block->error_log) && (!defined $block->no_error_log)) {
+        $block->set_value("no_error_log", "[error]");
+    }
+
+    $block;
+});
+
+run_tests;
+
+__DATA__
+
+=== TEST 1: set custom log format
+--- extra_init_by_lua
+    local exp = require("apisix.plugins.example-plugin")
+    exp.destroy = function()
+        ngx.log(ngx.WARN, "destroy method called")
+    end
+--- config
+    location /t {
+        return 200 "dummy";
+    }
+--- shutdown_error_log
+destroy method called