feat(ext-plugin-post-resp): support get response body by extra_info (#…

…7947)

Co-authored-by: soulbird <zhaothree@gmail.com>

apisix/plugins/ext-plugin-post-resp.lua

@@ -16,6 +16,7 @@
 --
 local core = require("apisix.core")
 local ext = require("apisix.plugins.ext-plugin.init")
+local helper = require("apisix.plugins.ext-plugin.helper")
 local constants = require("apisix.constants")
 local http = require("resty.http")
 
@@ -100,36 +101,46 @@ local function get_response(ctx, http_obj)
     return res, err
 end
 
+local function send_chunk(chunk)
+    if not chunk then
+        return nil
+    end
 
-local function send_response(res, code)
-    ngx.status = code or res.status
+    local ok, print_err = ngx_print(chunk)
+    if not ok then
+        return "output response failed: ".. (print_err or "")
+    end
+    local ok, flush_err = ngx_flush(true)
+    if not ok then
+        core.log.warn("flush response failed: ", flush_err)
+    end
 
-    local reader = res.body_reader
-    repeat
-        local chunk, ok, read_err, print_err, flush_err
-        -- TODO: HEAD or 304
-        chunk, read_err = reader()
-        if read_err then
-            return "read response failed: ".. (read_err or "")
-        end
+    return nil
+end
 
-        if chunk then
-            ok, print_err = ngx_print(chunk)
-            if not ok then
-                return "output response failed: ".. (print_err or "")
-            end
-            ok, flush_err = ngx_flush(true)
-            if not ok then
-                core.log.warn("flush response failed: ", flush_err)
+-- TODO: response body is empty (304 or HEAD)
+-- If the upstream returns 304 or the request method is HEAD,
+-- there is no response body. In this case,
+-- we need to send a response to the client in the plugin,
+-- instead of continuing to execute the subsequent plugin.
+local function send_response(ctx, res, code)
+    ngx.status = code or res.status
+
+    local chunks = ctx.runner_ext_response_body
+    if chunks then
+        for i=1, #chunks do
+            local err = send_chunk(chunks[i])
+            if err then
+                return err
             end
         end
-    until not chunk
+        return
+    end
 
-    return nil
+    return helper.response_reader(res.body_reader, send_chunk)
 end
 
 
-
 function _M.check_schema(conf)
     return core.schema.check(_M.schema, conf)
 end
@@ -157,7 +168,7 @@ function _M.before_proxy(conf, ctx)
     core.log.info("ext-plugin will send response")
 
     -- send origin response, status maybe changed.
-    err = send_response(res, code)
+    err = send_response(ctx, res, code)
     close(http_obj)
 
     if err then

apisix/plugins/ext-plugin/helper.lua

@@ -56,4 +56,26 @@ function _M.get_conf_token_cache_time()
 end
 
 
+function _M.response_reader(reader, callback, ...)
+    if not reader then
+        return "get response reader failed"
+    end
+
+    repeat
+        local chunk, read_err, cb_err
+        chunk, read_err = reader()
+        if read_err then
+            return "read response failed: ".. (read_err or "")
+        end
+
+        if chunk then
+            cb_err = callback(chunk, ...)
+            if cb_err then
+                return cb_err
+            end
+        end
+    until not chunk
+end
+
+
 return _M

apisix/plugins/ext-plugin/init.lua

@@ -31,6 +31,7 @@ local extra_info_req = require("A6.ExtraInfo.Req")
 local extra_info_var = require("A6.ExtraInfo.Var")
 local extra_info_resp = require("A6.ExtraInfo.Resp")
 local extra_info_reqbody = require("A6.ExtraInfo.ReqBody")
+local extra_info_respbody = require("A6.ExtraInfo.RespBody")
 local text_entry = require("A6.TextEntry")
 local err_resp = require("A6.Err.Resp")
 local err_code = require("A6.Err.Code")
@@ -304,7 +305,31 @@ local function handle_extra_info(ctx, input)
         if err then
             core.log.error("failed to read request body: ", err)
         end
-
+    elseif info_type == extra_info.RespBody then
+        local ext_res = ctx.runner_ext_response
+        if ext_res then
+            local info = req:Info()
+            local respbody_req = extra_info_respbody.New()
+            respbody_req:Init(info.byte, info.pos)
+
+            local chunks = {}
+            local err = helper.response_reader(ext_res.body_reader, function (chunk, chunks)
+                -- When the upstream response is chunked type,
+                -- we will receive the complete response body
+                -- before sending it to the runner program
+                -- to reduce the number of RPC calls.
+                core.table.insert_tail(chunks, chunk)
+            end, chunks)
+            if err then
+                -- TODO: send RPC_ERROR to runner
+                core.log.error(err)
+            else
+                res = core.table.concat(chunks)
+                ctx.runner_ext_response_body = chunks
+            end
+        else
+            core.log.error("failed to read response body: not exits")
+        end
     else
         return nil, "unsupported info type: " .. info_type
     end
@@ -732,9 +757,26 @@ local rpc_handlers = {
             return nil, "failed to send RPC_HTTP_RESP_CALL: " .. err
         end
 
-        local ty, resp = receive(sock)
-        if ty == nil then
-            return nil, "failed to receive RPC_HTTP_RESP_CALL: " .. resp
+        local ty, resp
+        while true do
+            ty, resp = receive(sock)
+            if ty == nil then
+                return nil, "failed to receive RPC_HTTP_REQ_CALL: " .. resp
+            end
+
+            if ty ~= constants.RPC_EXTRA_INFO then
+                break
+            end
+
+            local out, err = handle_extra_info(ctx, resp)
+            if not out then
+                return nil, "failed to handle RPC_EXTRA_INFO: " .. err
+            end
+
+            local ok, err = send(sock, constants.RPC_EXTRA_INFO, out)
+            if not ok then
+                return nil, "failed to reply RPC_EXTRA_INFO: " .. err
+            end
         end
 
         if ty ~= constants.RPC_HTTP_RESP_CALL then

docs/en/latest/plugins/ext-plugin-post-resp.md

@@ -45,10 +45,6 @@ See [External Plugin](../external-plugin.md) to learn more.
 
 Execution of External Plugins will affect the response of the current request.
 
-External Plugin does not yet support getting request context information.
-
-External Plugin does not yet support getting the response body of an upstream response.
-
 :::
 
 ## Attributes

docs/zh/latest/plugins/ext-plugin-post-resp.md

@@ -45,10 +45,6 @@ description: 本文介绍了关于 Apache APISIX `ext-plugin-post-resp` 插件
 
 External Plugin 执行的结果会影响当前请求的响应。
 
-External Plugin 尚不支持获取请求的上下文信息。
-
-External Plugin 尚不支持获取上游响应的响应体。
-
 :::
 
 ## 属性

rockspec/apisix-master-0.rockspec

@@ -68,7 +68,7 @@ dependencies = {
     "luasec = 0.9-1",
     "lua-resty-consul = 0.3-2",
     "penlight = 1.9.2-1",
-    "ext-plugin-proto = 0.5.0",
+    "ext-plugin-proto = 0.6.0",
     "casbin = 1.41.1",
     "api7-snowflake = 2.0-1",
     "inspect == 3.1.1",