Add Documentation for NamespacedInterceptor

docs/interceptors.md

@@ -24,7 +24,7 @@ transformation, define and test trigger conditions, and implement other useful p
 the payload data to the `TriggerBinding`. You can also use an `Interceptor` to modify the behavior of the associated `Trigger`.
 
 Tekton Triggers currently supports two distinct `Interceptor` implementations:
-- Standalone `Interceptors`, which are instances of the [`ClusterInterceptor`](./clusterinterceptors.md) Custom Resource Definition (CRD). You specify these `Interceptors` by referencing them,
+- Standalone `Interceptors`, which are instances of the [`Interceptor`](./namespacedinterceptor) or the [`ClusterInterceptor`](./clusterinterceptors.md) Custom Resource Definition (CRD). You specify these `Interceptors` by referencing them,
   along with the desired parameters, within your  `EventListener`. You can use the `ClusterInterceptor` CRD to implement your own custom `Interceptors`.
 - Legacy `Interceptors`, which you define entirely as part of the `EventListener` definition. This implementation will eventually be deprecated, so please consider
   transitioning to standalone `Interceptors` as soon as possible. See [TEP-0026](https://github.com/tektoncd/community/blob/main/teps/0026-interceptor-plugins.md) for more context on this change.
@@ -42,9 +42,9 @@ Tekton Triggers ships with the following `Interceptors` to help you get started:
 
 To specify an `Interceptor` within your `EventListener`, create an `interceptors:` field with the following sub-fields:
 - `name` - (optional) a name that uniquely identifies this `Interceptor` definition
-- `ref` - a reference to a [`ClusterInterceptor`](./clusterinterceptors.md) object with the following fields:
+- `ref` - a reference to a [`ClusterInterceptor`](./clusterinterceptors.md) or [`Interceptor`](./namespacedinterceptors.md) object with the following fields:
   - `name` - the name of the referenced `ClusterInterceptor`
-  - `kind` - (optional) specifies that the referenced Kubernetes object is a `ClusterInterceptor` object
+  - `kind` - (optional) specifies that whether the referenced Kubernetes object is a `ClusterInterceptor` object or `NamespacedInterceptor`. Default value is `ClusterInterceptor`
   - `apiVersion` - (optional) specifies the target API version, for example `triggers.tekton.dev/v1alpha1`
   - `params` - `name`/`value` pairs that specify the parameters you want to pass to the `ClusterInterceptor`
 - `params` - (optional) `name`/`value` pairs that specify the desired parameters for the `Interceptor`;
@@ -565,4 +565,4 @@ field both in the body of the payload as well as via the extra fields added to t
 
 ## Implementing custom `Interceptors`
 
-Tekton Triggers ships with the `ClusterInterceptor` Custom Resource Definition (CRD), which you can use to implement custom `Interceptors`. See [`ClusterInterceptors`](./clusterinterceptors.md) for more information.
+Tekton Triggers ships with the `ClusterInterceptor`and `Interceptor` Custom Resource Definition (CRD), which you can use to implement custom `Interceptors`. See [`ClusterInterceptors`](./clusterinterceptors.md) and [`NamespacedInterceptors`](./namespacedinterceptors.md)  for more information.

docs/namespacedinterceptors.md

@@ -0,0 +1,76 @@
+<!--
+---
+linkTitle: "Namespaced Interceptors"
+weight: 5
+---
+-->
+# `Interceptors`
+
+Tekton Triggers ships with the `Interceptor` Custom Resource Definition (CRD), which allows you to implement a custom namespaced-scoped Webhook-style `Interceptor`.
+
+A `Interceptor` specifies an external Kubernetes v1 Service running custom business logic that receives the event payload from the
+`EventListener` via an HTTP request and returns a processed version of the payload along with an HTTP 200 response. The `Interceptor` can also
+halt processing if the event payload does not meet criteria you have configured as well as add extra fields that are accessible in the `EventListener's`
+top-level `extensions` field to other [`Interceptors`](interceptors.md) and `Interceptors` chained with it and the associated `TriggerBinding`.
+
+## Structure of a `Interceptor`
+
+A `Interceptor` definition consists of the following fields:
+
+- Required:
+  - [`apiVersion`][kubernetes-overview] - specifies the target API version, for example `triggers.tekton.dev/v1alpha1`
+  - [`kind`][kubernetes-overview] - specifies that this Kubernetes resource is a `Interceptor` object
+  - [`metadata`][kubernetes-overview] - specifies data that uniquely identifies this `Interceptor` object, for example a `name`
+  - [`spec`][kubernetes-overview] - specifies the configuration information for this `Interceptor` object, including:
+    - [`clientConfig`] -  specifies how a client, such as an `EventListener` communicates with this `Interceptor` object
+
+[kubernetes-overview]:
+  https://kubernetes.io/docs/concepts/overview/working-with-objects/kubernetes-objects/#required-fields
+
+## Configuring the client of the `Interceptor`
+
+The `clientConfig` field specifies the client, such as an `EventListener` and how it communicates with the `Interceptor` to exchange
+event payload and other data. You can configure this field in one of the following ways:
+
+- Specify the `url` field and as its value a URL at which the corresponding Kubernetes service listens for incoming requests from this `Interceptor`
+- Specify the `service` field and within it reference the corresponding Kubernetes service that's listening for incoming requests from this `Interceptor`
+
+For example:
+
+```yaml
+spec:
+  clientConfig:
+    url: "http://interceptor-svc.default.svc/"
+---
+spec:
+  clientConfig:
+    service:
+      name: "my-interceptor-svc"
+      namespace: "default"
+      path: "/optional-path" # optional
+      port: 8081 # defaults to 80
+```
+
+## Configuring a Kubernetes Service for the `Interceptor`
+
+The Kubernetes object running the custom business logic for your `Interceptor` must meet the following criteria:
+
+- Fronted by a regular Kubernetes v1 Service listening on an HTTP port (default port is 80)
+- Accepts an HTTP `POST` request that contains an [`InterceptorRequest`](https://pkg.go.dev/github.com/tektoncd/triggers/pkg/apis/triggers/v1alpha1#InterceptorRequest) 
+  as a JSON body
+- Returns an HTTP 200 OK response that contains an [`InterceptorResponse`](https://pkg.go.dev/github.com/tektoncd/triggers/pkg/apis/triggers/v1alpha1#InterceptorResponse) 
+  as a JSON body. If the trigger processing should continue, the interceptor should set the `continue` field in the response to `true`. If the processing should be stopped, the interceptor should set the `continue` field to `false` and also provide additional information detailing the error in the `status` field.
+- Returns a response other than HTTP 200 OK only if payload processing halts due to a catastrophic failure. 
+
+### Running Interceptor as HTTPS
+
+Triggers support writing custom interceptor for both `http` and `https`. Support of `http` for custom interceptor will be removed in future and only `https` will be supported.
+
+End user who write `https` custom interceptor need to pass `caBundle` as well as label
+```yaml
+  labels:
+    server/type: https
+```
+to `Interceptor` in order to make secure connection with eventlistener.
+
+Here is the reference for writing [https server for custom interceptor](https://github.com/tektoncd/triggers/blob/main/cmd/interceptors/main.go). 

docs/triggers.md

@@ -22,6 +22,9 @@ When creating a `Trigger` definition you must specify the required fields and ca
                      definition using a `name`/`value` pair.
     - [`template`] - Specifies the corresponding `TriggerTemplate` either as a reference as an embedded `TriggerTemplate` definition.
     - [`interceptors`] - (Optional) specifies one or more `Interceptors` that will process the payload data before passing it to the `TriggerTemplate`.
+    - `ref` - a reference to a [`ClusterInterceptor`](./clusterinterceptors.md) or [`Interceptor`](./namespacedinterceptors.md) object with the following fields:
+      - `name` - the name of the referenced `ClusterInterceptor`
+      - `kind` - (Optional) specifies that whether the referenced Kubernetes object is a `ClusterInterceptor` object or `NamespacedInterceptor`. Default value is `ClusterInterceptor`
     - [`serviceAccountName`] - (Optional) Specifies the `ServiceAccount` to supply to the `EventListener` to instantiate/execute the target resources.
 
 Below is an example `Trigger` definition: