feat: file logger plugin support response body in variable

apisix/core/ctx.lua

@@ -209,10 +209,14 @@ do
         balancer_port = true,
         consumer_group_id = true,
         consumer_name = true,
+        resp_body = function(ctx)
+            -- only for logger and requires the logger to have a special configuration
+            return ctx.resp_body or ''
+        end,
         route_id = true,
         route_name = true,
         service_id = true,
-        service_name = true,
+        service_name = true
     }
 
     local mt = {

docs/en/latest/apisix-variable.md

@@ -49,5 +49,6 @@ additional variables.
 | service_name        | core       | Name of Service.                                                                    |                |
 | redis_cmd_line      | Redis      | The content of Redis command.                                                       |                |
 | rpc_time            | xRPC       | Time spent at the rpc request level.                                                |                |
+| resp_body           | core       | This variable is only for logger and requires the logger plugin to have a special configuration like `include_resp_body`. |                |
 
 You can also register your own [variable](./plugin-develop.md#register-custom-variable).

docs/zh/latest/apisix-variable.md

@@ -48,5 +48,6 @@ APISIX 除了支持 [NGINX 变量](http://nginx.org/en/docs/varindex.html)外，
 | service_name        | core       | APISIX 服务的名称。                                                               |                   |
 | redis_cmd_line      | Redis      | Redis 命令的内容。                                                                |                   |
 | rpc_time            | xRPC       | 在 RPC 请求级别所花费的时间。                                                      |                   |
+| resp_body           | core       | 此变量仅用于 Logger，并要求对应的 Logger 需要具备某些配置。                            |                  |
 
 当然，除上述变量外，你也可以创建自定义[变量](./plugin-develop.md#register-custom-variable)。

t/plugin/file-logger2.t

@@ -181,3 +181,96 @@ contain with target
 --- response_body
 contain target body hits with expr
 skip unconcern body
+
+
+
+=== TEST 5: add plugin metadata
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/plugin_metadata/file-logger',
+                ngx.HTTP_PUT,
+                [[{
+                    "log_format": {
+                        "host": "$host",
+                        "client_ip": "$remote_addr",
+                        "resp_body": "$resp_body"
+                    }
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 6: add plugin
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                 ngx.HTTP_PUT,
+                 [[{
+                        "plugins": {
+                            "file-logger": {
+                                "path": "file-with-resp-body2.log",
+                                "include_resp_body": true
+                            }
+                        },
+                        "upstream": {
+                            "nodes": {
+                                "127.0.0.1:1982": 1
+                            },
+                            "type": "roundrobin"
+                        },
+                        "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 7: verify plugin
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local t = require("lib.test_admin").test
+            local code = t("/hello", ngx.HTTP_GET)
+            local fd, err = io.open("file-with-resp-body2.log", 'r')
+            local msg
+
+            if not fd then
+                core.log.error("failed to open file: file.log, error info: ", err)
+                return
+            end
+
+            msg = fd:read()
+
+            local new_msg = core.json.decode(msg)
+            if new_msg.resp_body == 'hello world\n'
+            then
+                msg = "write file log success"
+                ngx.status = code
+                ngx.say(msg)
+            end
+        }
+    }
+--- response_body
+write file log success