docs: add buffer plugin (#284)

Signed-off-by: spacewander <[email protected]>

site/content/en/docs/reference/plugins/buffer.md

@@ -0,0 +1,76 @@
+---
+title: Buffer
+---
+
+## Description
+
+The `buffer` plugin fully buffers the complete request, by leveraging Envoy's `buffer` filter. It can be used for several purposes, like:
+
+* Protecting applications from high network latency.
+* Some plugins will buffer the whole request, which may trigger a 413 HTTP status code when the max request body size is met. We can set the `maxRequestBytes` larger than `per_connection_buffer_limit_bytes` to increase the max request body size per route.
+
+## Attribute
+
+|       |         |
+|-------|---------|
+| Type  | General |
+| Order | Outer   |
+
+## Configuration
+
+| Name            | Type   | Required | Validation | Description                                                                                |
+|-----------------|--------|----------|------------|--------------------------------------------------------------------------------------------|
+| maxRequestBytes | uint32 | True     |            | The maximum request body size that the filter will buffer before returning a 413 response. |
+
+## Usage
+
+Assumed we have the HTTPRoute below attached to `localhost:10000`, and a backend server listening to port `8080`:
+
+```yaml
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: default
+spec:
+  parentRefs:
+  - name: default
+    namespace: default
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /
+    backendRefs:
+    - name: backend
+      port: 8080
+```
+
+By applying the configuration below, the request to `http://localhost:10000/` is buffered until the body length meets the max requests bytes 4:
+
+```yaml
+apiVersion: mosn.io/v1
+kind: HTTPFilterPolicy
+metadata:
+  name: policy
+spec:
+  targetRef:
+    group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    name: default
+  filters:
+    buffer:
+      config:
+        maxRequestBytes: 4
+```
+
+We can test it out:
+
+```
+$ curl -d "hello" http://localhost:10000/ -i
+HTTP/1.1 413 Payload Too Large
+```
+
+```
+$ curl -d "hell" http://localhost:10000/ -i
+HTTP/1.1 200 OK
+```

site/content/en/docs/reference/plugins/consumer_restriction.md

@@ -17,22 +17,22 @@ The `consumerRestriction` plugin determines whether the current consumer has acc
 
 | Name  | Type  | Required | Validation | Description                          |
 |-------|-------|----------|------------|--------------------------------------|
-| allow | Rules | No       |            | List of rules allowing access access |
-| deny  | Rules | No       |            | List of rules denying access access  |
+| allow | Rules | False    |            | List of rules allowing access access |
+| deny  | Rules | False    |            | List of rules denying access access  |
 
 Only one of `allow` or `deny` can be configured.
 
 ### Rules
 
 | Name  | Type   | Required | Validation     | Description        |
 |-------|--------|----------|----------------|--------------------|
-| rules | Rule[] | Yes      | min_items: 1   | List of rules      |
+| rules | Rule[] | True     | min_items: 1   | List of rules      |
 
 ## Rule
 
 | Name | Type   | Required | Validation   | Description          |
 |------|--------|----------|--------------|----------------------|
-| name | string | Yes      | min_len: 1   | Name of the Consumer |
+| name | string | True     | min_len: 1   | Name of the Consumer |
 
 
 ## Usage
@@ -135,4 +135,4 @@ spec:
         deny:
           rules:
           - name: rick
-```
+```

site/content/zh-hans/docs/reference/plugins/buffer.md

@@ -0,0 +1,75 @@
+---
+title: Buffer
+---
+
+## 说明
+
+`buffer` 插件通过利用 Envoy 的 `buffer` 过滤器完全缓冲整个请求。它可以用于几个目的，比如：
+
+* 保护应用程序免受高网络延迟的影响。
+* 一些插件会缓冲整个请求。当请求体超过最大长度时，将触发 413 HTTP 状态码。我们可以设置 `maxRequestBytes` 大于 `per_connection_buffer_limit_bytes` 来增加单个路由的最大请求体大小。
+
+## 属性
+|       |         |
+|-------|---------|
+| Type  | General |
+| Order | Outer   |
+
+## 配置
+
+| 名称            | 类型   | 必选 | 校验规则 | 说明                                                                                |
+|-----------------|--------|------|----------|-------------------------------------------------------------------------------------|
+| maxRequestBytes | uint32 | 是   |          | 缓冲的请求体最大大小，超过此大小将返回 413 响应。                                      |
+
+## 用法
+
+假设我们有下面附加到 `localhost:10000` 的 HTTPRoute，并且有一个后端服务器监听端口 `8080`：
+
+```yaml
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: default
+spec:
+  parentRefs:
+  - name: default
+    namespace: default
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /
+    backendRefs:
+    - name: backend
+      port: 8080
+```
+
+通过应用下面的配置，发送到 `http://localhost:10000/` 的请求会被缓冲，直到请求体长度达到最大请求字节数 4：
+
+```yaml
+apiVersion: mosn.io/v1
+kind: HTTPFilterPolicy
+metadata:
+  name: policy
+spec:
+  targetRef:
+    group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    name: default
+  filters:
+    buffer:
+      config:
+        maxRequestBytes: 4
+```
+
+我们可以测试一下：
+
+```
+$ curl -d "hello" http://localhost:10000/ -i
+HTTP/1.1 413 Payload Too Large
+```
+
+```
+$ curl -d "hell" http://localhost:10000/ -i
+HTTP/1.1 200 OK
+```