feat(reponse-rewrite): allow using variable in the header (#4194)

* feat(reponse-rewrite): allow using variable in the header Fix #3727 Signed-off-by: spacewander <[email protected]>
apache · May 10, 2021 · db5a5a9 · db5a5a9
1 parent 28ebf3e
commit db5a5a9
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Showing 4 changed files with 62 additions and 5 deletions.
diff --git a/apisix/plugins/response-rewrite.lua b/apisix/plugins/response-rewrite.lua
@@ -168,7 +168,8 @@ function _M.header_filter(conf, ctx)
 
     local field_cnt = #conf.headers_arr
     for i = 1, field_cnt, 2 do
-        ngx.header[conf.headers_arr[i]] = conf.headers_arr[i+1]
+        local val = core.utils.resolve_var(conf.headers_arr[i+1], ctx.var)
+        ngx.header[conf.headers_arr[i]] = val
     end
 end
 

diff --git a/docs/en/latest/plugins/response-rewrite.md b/docs/en/latest/plugins/response-rewrite.md
@@ -46,7 +46,7 @@ response rewrite plugin, rewrite the content returned by the upstream as well as
 | status_code | integer | optional    |         | [200, 598] | New `status code` to client, keep the original response code by default.                                                                                                                                                      |
 | body        | string  | optional    |         |            | New `body` to client, and the content-length will be reset too.                                                                                                                                                               |
 | body_base64 | boolean | optional    | false   |            | Identify if `body` in configuration need base64 decoded before rewrite to client.                                                                                                                                             |
-| headers     | object  | optional    |         |            | Set the new `headers` for client, can set up multiple. If it exists already from upstream, will rewrite the header, otherwise will add the header. You can set the corresponding value to an empty string to remove a header. |
+| headers     | object  | optional    |         |            | Set the new `headers` for client, can set up multiple. If it exists already from upstream, will rewrite the header, otherwise will add the header. You can set the corresponding value to an empty string to remove a header. The value can contain Nginx variables in `$var` format, like `$remote_addr $balancer_ip` |
 | vars     | array[]  | optional    |         |            | A DSL to evaluate with the given ngx.var. See `vars` [lua-resty-expr](https://github.com/api7/lua-resty-expr#operator-list). if the `vars` is empty, then all rewrite operations will be executed unconditionally |
 
 ## How To Enable
@@ -63,7 +63,8 @@ curl http://127.0.0.1:9080/apisix/admin/routes/1  -H 'X-API-KEY: edd1c9f034335f1
             "body": "{\"code\":\"ok\",\"message\":\"new json body\"}",
             "headers": {
                 "X-Server-id": 3,
-                "X-Server-status": "on"
+                "X-Server-status": "on",
+                "X-Server-balancer_addr": "$balancer_ip:$balancer_port"
             },
             "vars":[
                 [ "status","==","200" ]
@@ -97,6 +98,7 @@ Transfer-Encoding: chunked
 Connection: keep-alive
 X-Server-id: 3
 X-Server-status: on
+X-Server-balancer_addr: 127.0.0.1:80
 
 {"code":"ok","message":"new json body"}
 ```

diff --git a/docs/zh/latest/plugins/response-rewrite.md b/docs/zh/latest/plugins/response-rewrite.md
@@ -45,7 +45,7 @@ title: response-rewrite
 | status_code | integer | 可选   |        | [200, 598] | 修改上游返回状态码，默认保留原始响应代码。                                                                                             |
 | body        | string  | 可选   |        |            | 修改上游返回的 `body` 内容，如果设置了新内容，header 里面的 content-length 字段也会被去掉                                              |
 | body_base64 | boolean | 可选   | false  |            | 描述 `body` 字段是否需要 base64 解码之后再返回给客户端，用在某些图片和 Protobuffer 场景                                                |
-| headers     | object  | 可选   |        |            | 返回给客户端的 `headers`，这里可以设置多个。头信息如果存在将重写，不存在则添加。想要删除某个 header 的话，把对应的值设置为空字符串即可 |
+| headers     | object  | 可选   |        |            | 返回给客户端的 `headers`，这里可以设置多个。头信息如果存在将重写，不存在则添加。想要删除某个 header 的话，把对应的值设置为空字符串即可。这个值能够以 `$var` 的格式包含 Nginx 变量，比如 `$remote_addr $balancer_ip` |
 | vars        | array[] | 可选   |        |            | `vars` 是一个表达式列表，只有满足条件的请求和响应才会修改 body 和 header 信息，来自 [lua-resty-expr](https://github.com/api7/lua-resty-expr#operator-list)。如果 `vars` 字段为空，那么所有的重写动作都会被无条件的执行。 |
 
 ## 示例
@@ -64,7 +64,8 @@ curl http://127.0.0.1:9080/apisix/admin/routes/1  -H 'X-API-KEY: edd1c9f034335f1
             "body": "{\"code\":\"ok\",\"message\":\"new json body\"}",
             "headers": {
                 "X-Server-id": 3,
-                "X-Server-status": "on"
+                "X-Server-status": "on",
+                "X-Server-balancer_addr": "$balancer_ip:$balancer_port"
             },
             "vars":[
                 [ "status","==","200" ]
@@ -97,6 +98,7 @@ Transfer-Encoding: chunked
 Connection: keep-alive
 X-Server-id: 3
 X-Server-status: on
+X-Server-balancer_addr: 127.0.0.1:80
 
 {"code":"ok","message":"new json body"}
 ```

diff --git a/t/plugin/response-rewrite.t b/t/plugin/response-rewrite.t
@@ -676,3 +676,55 @@ GET /t
 invalid base64 content
 --- no_error_log
 [error]
+
+
+
+=== TEST 24: rewrite header with variables
+--- 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": {
+                        "response-rewrite": {
+                            "headers" : {
+                                "X-A": "$remote_addr",
+                                "X-B": "from $remote_addr to $balancer_ip:$balancer_port"
+                            }
+                        }
+                    },
+                    "upstream": {
+                        "nodes": {
+                            "127.0.0.1:1980": 1
+                        },
+                        "type": "roundrobin"
+                    },
+                    "uri": "/with_header"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 25: hit
+--- request
+GET /with_header
+--- response_headers
+X-A: 127.0.0.1
+X-B: from 127.0.0.1 to 127.0.0.1:1980
+--- no_error_log
+[error]