feature: supported priority for route.

doc/admin-api-cn.md

@@ -57,6 +57,7 @@
 |remote_addr|可选 |匹配规则|客户端请求 IP 地址: `192.168.1.101`、`192.168.1.102` 以及 CIDR 格式的支持 `192.168.1.0/24`。特别的，APISIX 也完整支持 IPv6 地址匹配：`::1`，`fe80::1`, `fe80::1/64` 等。|"192.168.1.0/24"|
 |remote_addrs|可选 |匹配规则|列表形态的 `remote_addr`，表示允许有多个不同 IP 地址，符合其中任意一个即可。|{"127.0.0.1", "192.0.0.0/8", "::1"}|
 |methods  |可选 |匹配规则|如果为空或没有该选项，代表没有任何 `method` 限制，也可以是一个或多个的组合：`GET`, `POST`, `PUT`, `DELETE`, `PATCH`, `HEAD`, `OPTIONS`，`CONNECT`，`TRACE`。|{"GET", "POST"}|
+|priority  |可选 |匹配规则|如果不同路由包含相同 `uri` ，根据属性 `priority` 确定哪个 `route` 被优先匹配。默认值为 `0`.|priority = 10|
 |vars       |可选  |匹配规则(仅支持 `radixtree` 路由)|由一个或多个`{var, operator, val}`元素组成的列表，类似这样：`{{var, operator, val}, {var, operator, val}, ...}`。例如：`{"arg_name", "==", "json"}`，表示当前请求参数 `name` 是 `json`。这里的 `var` 与 Nginx 内部自身变量命名是保持一致，所以也可以使用 `request_uri`、`host` 等；对于 `operator` 部分，目前已支持的运算符有 `==`、`~=`、`>`、`<` 和 `~~`。对于`>`和`<`两个运算符，会把结果先转换成 number 然后再做比较。查看支持的[运算符列表](#运算符列表)|{{"arg_name", "==", "json"}, {"arg_age", ">", 18}}|
 |filter_func|可选|匹配规则|用户自定义的过滤函数。可以使用它来实现特殊场景的匹配要求实现。该函数默认接受一个名为 vars 的输入参数，可以用它来获取 Nginx 变量。|function(vars) return vars["arg_name"] == "json" end|
 |plugins  |可选 |Plugin|详见 [Plugin](architecture-design-cn.md#plugin) ||

doc/admin-api.md

@@ -56,6 +56,7 @@ Table of contents
 |remote_addr|False |Match Rules|The client requests an IP address: `192.168.1.101`, `192.168.1.102`, and CIDR format support `192.168.1.0/24`. In particular, APISIX also fully supports IPv6 address matching: `::1`, `fe80::1`, `fe80::1/64`, etc.|"192.168.1.0/24"|
 |remote_addrs|False |Match Rules|The `remote_addr` in the form of a list indicates that multiple different IP addresses are allowed, and match any one of them.|{"127.0.0.1", "192.0.0.0/8", "::1"}|
 |methods  |False |Match Rules|If empty or without this option, there are no `method` restrictions, and it can be a combination of one or more: `GET`,`POST`,`PUT`,`DELETE`,`PATCH`, `HEAD`,`OPTIONS`,`CONNECT`,`TRACE`.|{"GET", "POST"}|
+|priority  |False |Match Rules|If different routes contain the same `uri`, determine which route is matched first based on the attribute` priority`. Default value is `0`.|priority = 10|
 |vars       |False  |Match Rules (only `radixtree` route is supported)|A list of one or more `{var, operator, val}` elements, like this: `{{var, operator, val}, {var, operator, val}, ...}`. For example: `{"arg_name", "==", "json"}` means that the current request parameter `name` is `json`. The `var` here is consistent with the internal variable name of Nginx, so you can also use `request_uri`, `host`, etc. For the operator part, the currently supported operators are `==`, `~=`,`>`, `<`, and `~~`. For the `>` and `<` operators, the result is first converted to `number` and then compared. See a list of [supported operators](#available-operators) |{{"arg_name", "==", "json"}, {"arg_age", ">", 18}}|
 |filter_func|False|Match Rules|User-defined filtering function. You can use it to achieve matching requirements for special scenarios. This function accepts an input parameter named `vars` by default, which you can use to get Nginx variables.|function(vars) return vars["arg_name"] == "json" end|
 |plugins  |False |Plugin|See [Plugin](architecture-design-cn.md#plugin) for more ||