Add middleware-routerchecker.md to v1.7 (#2623)

* add file

Signed-off-by: Hannah Hunter <hannahhunter@microsoft.com>

* add to table

Signed-off-by: Hannah Hunter <hannahhunter@microsoft.com>

* Update daprdocs/data/components/middleware/http.yaml

Co-authored-by: greenie-msft <56556602+greenie-msft@users.noreply.github.com>
Co-authored-by: Mark Fussell <markfussell@gmail.com>

daprdocs/content/en/reference/components-reference/supported-middleware/middleware-routerchecker.md

@@ -0,0 +1,71 @@
+---
+type: docs
+title: "RouterChecker http request routing"
+linkTitle: "RouterChecker"
+description: "Use routerchecker middleware to block invalid http request routing"
+aliases:
+- /developing-applications/middleware/supported-middleware/middleware-routerchecker/
+---
+
+The RouterChecker HTTP [middleware]({{< ref middleware.md >}}) component leverages regexp to check the validity of HTTP request routing to prevent invalid routers from entering the Dapr cluster. In turn, the RouterChecker component filters out bad requests and reduces noise in the telemetry and log data.
+
+## Component format
+
+The RouterChecker applies a set of rules to the incoming HTTP request. You define these rules in the component metadata using regular expressions. In the following example, the HTTP request RouterChecker is set to validate all requests message against the `^[A-Za-z0-9/._-]+$`: regex.
+
+```yaml
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: routerchecker 
+spec:
+  type: middleware.http.routerchecker
+  version: v1gi
+  metadata:
+  - name: rule
+    value: "^[A-Za-z0-9/._-]+$"
+```
+
+In this example, the above definition would result in the following PASS/FAIL cases:
+
+```shell
+PASS /v1.0/invoke/demo/method/method
+PASS /v1.0/invoke/demo.default/method/method
+PASS /v1.0/invoke/demo.default/method/01
+PASS /v1.0/invoke/demo.default/method/METHOD
+PASS /v1.0/invoke/demo.default/method/user/info
+PASS /v1.0/invoke/demo.default/method/user_info
+PASS /v1.0/invoke/demo.default/method/user-info
+
+FAIL /v1.0/invoke/demo.default/method/cat password
+FAIL /v1.0/invoke/demo.default/method/" AND 4210=4210 limit 1
+FAIL /v1.0/invoke/demo.default/method/"$(curl
+```
+
+## Spec metadata fields
+
+| Field | Details | Example |
+|-------|---------|---------|
+| rule | the regexp expression to be used by the HTTP request RouterChecker | `^[A-Za-z0-9/._-]+$`|
+
+## Dapr configuration
+
+To be applied, the middleware must be referenced in [configuration]({{< ref configuration-concept.md >}}). See [middleware pipelines]({{< ref "middleware.md#customize-processing-pipeline">}}).
+
+```yaml
+apiVersion: dapr.io/v1alpha1
+kind: Configuration
+metadata:
+  name: appconfig
+spec:
+  httpPipeline:
+    handlers:
+    - name: routerchecker 
+      type: middleware.http.routerchecker
+```
+
+## Related links
+
+- [Middleware]({{< ref middleware.md >}})
+- [Configuration concept]({{< ref configuration-concept.md >}})
+- [Configuration overview]({{< ref configuration-overview.md >}})

daprdocs/data/components/middleware/http.yaml

@@ -23,6 +23,11 @@
   state: Alpha
   version: v1
   description: Applies [Rego/OPA Policies](https://www.openpolicyagent.org/) to incoming Dapr HTTP requests
+- component: RouterChecker
+  link: middleware-routerchecker
+  state: Alpha
+  version: v1
+  description: Use RouterChecker middleware to block invalid http request routing
 - component: Uppercase
   link: middleware-uppercase
   state: Stable