feature: support body filter plugin echo. (#1632)

apisix/plugins/echo.lua

@@ -0,0 +1,73 @@
+--
+-- 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 ngx         = ngx
+
+local schema = {
+    type = "object",
+    properties = {
+        before_body = {
+            description = "body before the filter phase.",
+            type = "string"
+        },
+        body = {
+            description = "body to replace upstream response.",
+            type = "string"
+        },
+        after_body = {
+            description = "body after the modification of filter phase.",
+            type = "string"
+        }
+    },
+    anyOf = {
+        {required = {"before_body"}},
+        {required = {"body"}},
+        {required = {"after_body"}}
+    },
+    minProperties = 1
+}
+
+local plugin_name = "echo"
+
+local _M = {
+    version = 0.1,
+    priority = 412,
+    name = plugin_name,
+    schema = schema,
+}
+
+
+function _M.check_schema(conf)
+    return core.schema.check(schema, conf)
+end
+
+function _M.body_filter(conf, ctx)
+    if conf.body then
+        ngx.arg[1] = conf.body
+    end
+
+    if conf.before_body then
+        ngx.arg[1] = conf.before_body ..  ngx.arg[1]
+    end
+
+    if conf.after_body then
+        ngx.arg[1] = ngx.arg[1] .. conf.after_body
+    end
+    ngx.arg[2] = true
+end
+
+return _M

conf/config.yaml

@@ -166,6 +166,7 @@ plugins:                          # plugin list
   - batch-requests
   - http-logger
   - skywalking
+  - echo
 
 stream_plugins:
   - mqtt-proxy

doc/plugins/echo-cn.md

@@ -0,0 +1,98 @@
+<!--
+#
+# 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.
+#
+-->
+
+# 目录
+- [**简介**](#简介)
+- [**属性**](#属性)
+- [**如何启用**](#如何启用)
+- [**测试插件**](#测试插件)
+- [**禁用插件**](#禁用插件)
+
+## 简介
+
+echo是一个有用的插件，可帮助用户尽可能全面地了解如何开发APISIX插件。
+
+
+该插件解决了常见阶段中的相应功能，例如初始化，重写，访问，平衡器
+，标题文件管理器，正文过滤器和日志。
+
+## 属性
+
+|属性名称          |必选项  |描述|
+|---------     |--------|-----------|
+| before_body |可选| 主体在过滤阶段之前。。|
+| body |可选| 身体替代上游反应。|
+| after_body |可选| 车身经过改装后的滤光相。|
+
+## 如何启用
+
+1. 为特定路由启用 echo 插件。
+
+```shell
+curl http://127.0.0.1:9080/apisix/admin/routes/5 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
+{
+    "plugins": {
+       "kafka-logger": {
+           "broker_list" :
+             {
+               "127.0.0.1":9092
+             },
+           "kafka_topic" : "test2",
+           "key" : "key1"
+       }
+    },
+    "upstream": {
+       "nodes": {
+           "127.0.0.1:1980": 1
+       },
+       "type": "roundrobin"
+    },
+    "uri": "/hello"
+}'
+```
+
+## 测试插件
+
+* 成功:
+
+```shell
+$ curl -i http://127.0.0.1:9080/hello
+HTTP/1.1 200 OK
+...
+hello, world
+```
+
+## 禁用插件
+
+当您要禁用`echo`插件时，这很简单，您可以在插件配置中删除相应的json配置，无需重新启动服务，它将立即生效：
+
+```shell
+$ curl http://127.0.0.1:2379/apisix/admin/routes/1  -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d value='
+{
+    "methods": ["GET"],
+    "uri": "/hello",
+    "plugins": {},
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "127.0.0.1:1980": 1
+        }
+    }
+}'
+```

doc/plugins/echo.md

@@ -0,0 +1,95 @@
+<!--
+#
+# 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.
+#
+-->
+
+# Summary
+- [**Name**](#name)
+- [**Attributes**](#attributes)
+- [**How To Enable**](#how-to-enable)
+- [**Test Plugin**](#test-plugin)
+- [**Disable Plugin**](#disable-plugin)
+
+
+## Name
+
+`echo` is a a useful plugin to help users understand as fully as possible how to develop an APISIX plugin.
+
+This plugin addresses the corresponding functionality in the common phases such as init, rewrite, access, balancer
+, header filer, body filter and log.
+
+## Attributes
+
+|Name           |Requirement    |Description|
+|---------      |--------       |-----------|
+| before_body   |optional       | Body before the filter phase.|
+| body   |optional       | Body to replace upstream response.|
+| after_body       |optional       |Body after the modification of filter phase.|
+
+
+## How To Enable
+
+The following is an example on how to enable the echo plugin for a specific route.
+
+```shell
+curl http://127.0.0.1:9080/apisix/admin/routes/5 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
+{
+    "plugins": {
+        "echo": {
+            "before_body": "before the body modification "
+        }
+    },
+    "upstream": {
+        "nodes": {
+            "127.0.0.1:1980": 1
+        },
+        "type": "roundrobin"
+    },
+    "uri": "/hello"
+}'
+```
+
+## Test Plugin
+
+* success:
+
+```shell
+$ curl -i http://127.0.0.1:9080/hello
+HTTP/1.1 200 OK
+...
+before the body modification hello world
+```
+
+## Disable Plugin
+
+Remove the corresponding json configuration in the plugin configuration to disable the `echo`.
+APISIX plugins are hot-reloaded, therefore no need to restart APISIX.
+
+```shell
+$ curl http://127.0.0.1:2379/apisix/admin/routes/1  -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d value='
+{
+    "methods": ["GET"],
+    "uri": "/hello",
+    "plugins": {},
+    "upstream": {
+        "type": "roundrobin",
+        "nodes": {
+            "127.0.0.1:1980": 1
+        }
+    }
+}'
+```

t/admin/plugins.t

@@ -30,7 +30,7 @@ __DATA__
 --- request
 GET /apisix/admin/plugins/list
 --- response_body_like eval
-qr/\["limit-req","limit-count","limit-conn","key-auth","basic-auth","prometheus","node-status","jwt-auth","zipkin","ip-restriction","grpc-transcode","serverless-pre-function","serverless-post-function","openid-connect","proxy-rewrite","redirect","response-rewrite","fault-injection","udp-logger","wolf-rbac","proxy-cache","tcp-logger","proxy-mirror","kafka-logger","cors","consumer-restriction","syslog","batch-requests","http-logger","skywalking"\]/
+qr/\["limit-req","limit-count","limit-conn","key-auth","basic-auth","prometheus","node-status","jwt-auth","zipkin","ip-restriction","grpc-transcode","serverless-pre-function","serverless-post-function","openid-connect","proxy-rewrite","redirect","response-rewrite","fault-injection","udp-logger","wolf-rbac","proxy-cache","tcp-logger","proxy-mirror","kafka-logger","cors","consumer-restriction","syslog","batch-requests","http-logger","skywalking","echo"\]/
 --- no_error_log
 [error]
 

t/debug/debug-mode.t

@@ -77,6 +77,7 @@ loaded plugin and sort by priority: 900 name: redirect
 loaded plugin and sort by priority: 899 name: response-rewrite
 loaded plugin and sort by priority: 506 name: grpc-transcode
 loaded plugin and sort by priority: 500 name: prometheus
+loaded plugin and sort by priority: 412 name: echo
 loaded plugin and sort by priority: 410 name: http-logger
 loaded plugin and sort by priority: 405 name: tcp-logger
 loaded plugin and sort by priority: 403 name: kafka-logger