feat: add inspect plugin

Makefile

@@ -300,6 +300,9 @@ install: runtime
 	$(ENV_INSTALL) -d $(ENV_INST_LUADIR)/apisix/include/apisix/model
 	$(ENV_INSTALL) apisix/include/apisix/model/*.proto $(ENV_INST_LUADIR)/apisix/include/apisix/model/
 
+	$(ENV_INSTALL) -d $(ENV_INST_LUADIR)/apisix/inspect
+	$(ENV_INSTALL) apisix/inspect/*.lua $(ENV_INST_LUADIR)/apisix/inspect/
+
 	$(ENV_INSTALL) -d $(ENV_INST_LUADIR)/apisix/plugins
 	$(ENV_INSTALL) apisix/plugins/*.lua $(ENV_INST_LUADIR)/apisix/plugins/
 

apisix/inspect/dbg.lua

@@ -0,0 +1,151 @@
+--
+-- 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.
+--
+local core = require("apisix.core")
+local string_format = string.format
+local debug = debug
+local ipairs = ipairs
+local pcall = pcall
+local table_insert = table.insert
+local jit = jit
+
+local _M = {}
+
+local hooks = {}
+
+function _M.getname(n)
+    if n.what == "C" then
+        return n.name
+    end
+    local lc = string_format("%s:%d", n.short_src, n.currentline)
+    if n.what ~= "main" and n.namewhat ~= "" then
+        return string_format("%s (%s)", lc, n.name)
+    else
+        return lc
+    end
+end
+
+local function hook(evt, arg)
+    local level = 2
+    local finfo = debug.getinfo(level, "nSlf")
+    local key = finfo.source .. "#" .. arg
+
+    local hooks2 = {}
+    for _, hook in ipairs(hooks) do
+        if key:sub(-#hook.key) == hook.key then
+            local filter_func = hook.filter_func
+            local info = {finfo = finfo, uv = {}, vals = {}}
+
+            -- upvalues
+            local i = 1
+            while true do
+                local name, value = debug.getupvalue(finfo.func, i)
+                if name == nil then break end
+                if name:sub(1, 1) ~= "(" then
+                    info.uv[name] = value
+                end
+                i = i + 1
+            end
+
+            -- local values
+            local i = 1
+            while true do
+                local name, value = debug.getlocal(level, i)
+                if not name then break end
+                if name:sub(1, 1) ~= "(" then
+                    info.vals[name] = value
+                end
+                i = i + 1
+            end
+
+            local r1, r2_or_err = pcall(filter_func, info)
+            if not r1 then
+                core.log.error("inspect: pcall filter_func:", r2_or_err)
+            elseif r2_or_err == false then
+                -- if filter_func returns false, keep the hook
+                table_insert(hooks2, hook)
+            end
+        else
+            -- key not match, keep the hook
+            table_insert(hooks2, hook)
+        end
+    end
+
+    -- disable debug mode if all hooks done
+    if #hooks2 ~= #hooks then
+        hooks = hooks2
+        if #hooks == 0 then
+            debug.sethook()
+        end
+    end
+end
+
+function _M.set_hook(file, line, func, filter_func)
+    if file == nil then
+        file = "=stdin"
+    end
+
+    local key = file .. "#" .. line
+    table_insert(hooks, {key = key, filter_func = filter_func})
+
+    if jit then
+        jit.flush(func)
+        jit.off()
+    end
+
+    debug.sethook(hook, "l")
+end
+
+function _M.unset_hook(file, line)
+    if file == nil then
+        file = "=stdin"
+    end
+
+    local hooks2 = {}
+
+    local key = file .. "#" .. line
+    for i, hook in ipairs(hooks) do
+        if hook.key ~= key then
+            table_insert(hooks2, hook)
+        end
+    end
+
+    if #hooks2 ~= #hooks then
+        hooks = hooks2
+        if #hooks == 0 then
+            debug.sethook()
+            if jit then
+                jit.on()
+            end
+        end
+    end
+end
+
+function _M.unset_all()
+    if #hooks > 0 then
+        hooks = {}
+        debug.sethook()
+        if jit then
+            jit.on()
+        end
+    end
+end
+
+function _M.hooks()
+    return hooks
+end
+
+return _M

apisix/inspect/init.lua

@@ -0,0 +1,127 @@
+--
+-- 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.
+--
+local core = require("apisix.core")
+local dbg = require("apisix.inspect.dbg")
+local lfs = require("lfs")
+local pl_path = require("pl.path")
+local io = io
+local table_insert = table.insert
+local pcall = pcall
+local ipairs = ipairs
+local os = os
+local ngx = ngx
+local loadstring = loadstring
+
+local _M = {}
+
+local last_modified = 0
+
+local stop = false
+
+local running = false
+
+local last_report_time = 0
+
+local REPORT_INTERVAL = 30 -- secs
+
+local function run_lua_file(file)
+    local f, err = io.open(file, "rb")
+    if not f then
+        return false, err
+    end
+    local code = f:read("*all")
+    f:close()
+    if code == nil then
+        return false, "cannot read hooks file"
+    end
+    local func, err = loadstring(code)
+    if not func then
+        return false, err
+    end
+    func()
+    return true
+end
+
+local function setup_hooks(file)
+    if pl_path.exists(file) then
+        dbg.unset_all()
+        local _, err = pcall(run_lua_file, file)
+        local hooks = {}
+        for _, hook in ipairs(dbg.hooks()) do
+            table_insert(hooks, hook.key)
+        end
+        core.log.info("set hooks: err=", err, ", hooks=", core.json.encode(hooks))
+    end
+end
+
+local function reload_hooks(premature, delay, file)
+    if premature or stop then
+        stop = false
+        running = false
+        return
+    end
+
+    local time, err = lfs.attributes(file, 'modification')
+    if err then
+        if last_modified ~= 0 then
+            core.log.info(err, ", disable all hooks")
+            dbg.unset_all()
+            last_modified = 0
+        end
+    elseif time ~= last_modified then
+        setup_hooks(file)
+        last_modified = time
+    else
+        local ts = os.time()
+        if ts - last_report_time >= REPORT_INTERVAL then
+            local hooks = {}
+            for _, hook in ipairs(dbg.hooks()) do
+                table_insert(hooks, hook.key)
+            end
+            core.log.info("alive hooks: ", core.json.encode(hooks))
+            last_report_time = ts
+        end
+    end
+
+    local ok, err = ngx.timer.at(delay, reload_hooks, delay, file)
+    if not ok then
+        core.log.error("failed to create the timer: ", err)
+        running = false
+    end
+end
+
+function _M.init(delay, file)
+    if not running then
+        file = file or "/var/run/apisix_inspect_hooks.lua"
+        delay = delay or 3
+
+        setup_hooks(file)
+
+        local ok, err = ngx.timer.at(delay, reload_hooks, delay, file)
+        if not ok then
+            core.log.error("failed to create the timer: ", err)
+            return
+        end
+        running = true
+    end
+end
+
+function _M.destroy()
+    stop = true
+end
+
+return _M

apisix/plugins/inspect.lua

@@ -0,0 +1,61 @@
+--
+-- 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.
+--
+local core = require("apisix.core")
+local plugin = require("apisix.plugin")
+local inspect = require("apisix.inspect")
+
+
+local plugin_name = "inspect"
+
+
+local schema = {
+    type = "object",
+    properties = {},
+}
+
+
+local _M = {
+    version = 0.1,
+    priority = 200,
+    name = plugin_name,
+    schema = schema,
+}
+
+
+function _M.check_schema(conf, schema_type)
+    return core.schema.check(schema, conf)
+end
+
+
+function _M.init()
+    local attr = plugin.plugin_attr(plugin_name)
+    local delay
+    local hooks_file
+    if attr then
+        delay = attr.delay
+        hooks_file = attr.hooks_file
+    end
+    core.log.info("delay=", delay, ", hooks_file=", hooks_file)
+    return inspect.init(delay, hooks_file)
+end
+
+
+function _M.destroy()
+    return inspect.destroy()
+end
+
+return _M

conf/config-default.yaml

@@ -461,6 +461,7 @@ plugins:                          # plugin list (sorted by priority)
   - file-logger                    # priority: 399
   - clickhouse-logger              # priority: 398
   - tencent-cloud-cls              # priority: 397
+  - inspect                        # priority: 200
   #- log-rotate                    # priority: 100
   # <- recommend to use priority (0, 100) for your custom plugins
   - example-plugin                 # priority: 0
@@ -555,6 +556,9 @@ plugin_attr:
       send: 60s
 #  redirect:
 #    https_port: 8443   # the default port for use by HTTP redirects to HTTPS
+  inspect:
+    delay: 3
+    hooks_file: "/var/run/apisix_inspect_hooks.lua"
 
 deployment:
   role: traditional

docs/en/latest/config.json

@@ -57,7 +57,8 @@
             "plugins/server-info",
             "plugins/ext-plugin-pre-req",
             "plugins/ext-plugin-post-req",
-            "plugins/ext-plugin-post-resp"
+            "plugins/ext-plugin-post-resp",
+            "plugins/inspect"
           ]
         },
         {