doc: add routePatch plugin (#790)

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

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

@@ -0,0 +1,137 @@
+---
+title: Route Patch
+---
+
+## Description
+
+The `routePatch` plugin allows users to directly apply patches to one or more Envoy routes corresponding to a VirtualService or HTTPRoute. Note that the TargetRef of the FilterPolicy configured with the `routePatch` plugin can only be a VirtualService or HTTPRoute.
+
+## Attribute
+
+|        |              |
+|--------|--------------|
+| Type   | General      |
+| Order  | Inner        |
+| Status | Experimental |
+
+## Configuration
+
+Please refer to the corresponding [Envoy documentation](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/route/v3/route_components.proto.html#envoy-v3-api-msg-config-route-v3-route).
+
+## Usage
+
+Suppose we have the following HTTPRoute attached to `localhost:10000`, and a backend server listening on port `8080`:
+
+```yaml
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: default
+spec:
+  parentRefs:
+  - name: default
+  rules:
+  - matches:
+    - path:
+        type: Exact
+        value: /reply
+    backendRefs:
+    - name: backend
+      port: 8080
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /
+    backendRefs:
+    - name: backend
+      port: 8080
+```
+
+By applying the following configuration, we can interrupt requests to `http://localhost:10000/` with a custom response:
+
+```yaml
+apiVersion: htnn.mosn.io/v1
+kind: FilterPolicy
+metadata:
+  name: policy
+spec:
+  targetRef:
+    group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    name: default
+  filters:
+    routePatch:
+      config:
+        directResponse:
+          status: 403
+```
+
+At this point, the two routes generated by HTTPRoute `default` will both have the direct_response field:
+
+```yaml
+routes:
+    - directResponse:
+        status: 403
+      match:
+        caseSensitive: true
+        path: /reply
+      name: e2e.default.0
+      ...
+    - directResponse:
+        status: 403
+      match:
+        caseSensitive: true
+        prefix: /
+      name: e2e.default.1
+      ...
+```
+
+We can also specify the names of specific routes so that the modifications only affect specific routes. In the configuration below, only the route named `last` will be patched:
+
+```yaml
+apiVersion: networking.istio.io/v1beta1
+kind: VirtualService
+metadata:
+  name: vs
+  namespace: istio-system
+spec:
+  gateways:
+  - default
+  hosts:
+  - "default.local"
+  http:
+  - match:
+    - uri:
+        prefix: /echo
+    route:
+    - destination:
+        host: backend
+        port:
+          number: 8080
+  - match:
+    - uri:
+        prefix: /
+    name: last
+    route:
+    - destination:
+        host: backend
+        port:
+          number: 8080
+---
+apiVersion: htnn.mosn.io/v1
+kind: FilterPolicy
+metadata:
+  name: policy
+  namespace: istio-system
+spec:
+  targetRef:
+    group: networking.istio.io
+    kind: VirtualService
+    name: vs
+    sectionName: last
+  filters:
+    routePatch:
+      config:
+        directResponse:
+          status: 403
+```

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

@@ -0,0 +1,137 @@
+---
+title: Route Patch
+---
+
+## 说明
+
+`routePatch` 插件允许用户直接给 VirtualService 或 HTTPRoute 对应的一个或多个 Envoy 路由打补丁。注意配置了 `routePatch` 插件的 FilterPolicy 的 TargetRef 只能是 VirtualService 或 HTTPRoute。
+
+## 属性
+
+|        |              |
+|--------|--------------|
+| Type   | General      |
+| Order  | Inner        |
+| Status | Experimental |
+
+## 配置
+
+请查阅对应的 [Envoy 文档](https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/route/v3/route_components.proto.html#envoy-v3-api-msg-config-route-v3-route)。
+
+## 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
+  rules:
+  - matches:
+    - path:
+        type: Exact
+        value: /reply
+    backendRefs:
+    - name: backend
+      port: 8080
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /
+    backendRefs:
+    - name: backend
+      port: 8080
+```
+
+通过应用下面的配置，我们可以用自定义响应中断对 `http://localhost:10000/` 的请求：
+
+```yaml
+apiVersion: htnn.mosn.io/v1
+kind: FilterPolicy
+metadata:
+  name: policy
+spec:
+  targetRef:
+    group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    name: default
+  filters:
+    routePatch:
+      config:
+        directResponse:
+          status: 403
+```
+
+此时由 HTTPRoute `default` 生成的两条路由都会带上 direct_response 字段：
+
+```yaml
+routes:
+    - directResponse:
+        status: 403
+      match:
+        caseSensitive: true
+        path: /reply
+      name: e2e.default.0
+      ...
+    - directResponse:
+        status: 403
+      match:
+        caseSensitive: true
+        prefix: /
+      name: e2e.default.1
+      ...
+```
+
+我们也可以指定具体路由的名字，让修改只对具体路由生效。在下面配置中只有名字为 `last` 的路由才会被打上补丁：
+
+```yaml
+apiVersion: networking.istio.io/v1beta1
+kind: VirtualService
+metadata:
+  name: vs
+  namespace: istio-system
+spec:
+  gateways:
+  - default
+  hosts:
+  - "default.local"
+  http:
+  - match:
+    - uri:
+        prefix: /echo
+    route:
+    - destination:
+        host: backend
+        port:
+          number: 8080
+  - match:
+    - uri:
+        prefix: /
+    name: last
+    route:
+    - destination:
+        host: backend
+        port:
+          number: 8080
+---
+apiVersion: htnn.mosn.io/v1
+kind: FilterPolicy
+metadata:
+  name: policy
+  namespace: istio-system
+spec:
+  targetRef:
+    group: networking.istio.io
+    kind: VirtualService
+    name: vs
+    sectionName: last
+  filters:
+    routePatch:
+      config:
+        directResponse:
+          status: 403
+```

tools/cmd/linter/main.go

@@ -667,7 +667,7 @@ func lintFeatureMaturityLevel() error {
 					break
 				}
 			}
-			if !found && record.Name != "route_patch" { // FIXME: temporary workaround, we don't have time to write its doc yet
+			if !found {
 				return fmt.Errorf("feature maturity record of %s %s is missing in the documentation", category, record.Name)
 			}
 		}