fix panic in github interceptor

We were passing the original request where the body had been drained
to the first interceptor meaning that the body to the first interceptor
in the chain was always empty. Further, we were using the `GetBody` which
can sometimes be empty leading to a panic.

wip:
 - tests for HandEventWithSingleInterceptor
 - tests for HandleEventWithMultipleInterceptors

fixes #355

Signed-off-by: Dibyo Mukherjee <[email protected]>

pkg/interceptors/cel/cel.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cel
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -58,12 +59,8 @@ func (w *Interceptor) ExecuteTrigger(request *http.Request) (*http.Response, err
 		return nil, fmt.Errorf("error creating cel environment: %w", err)
 	}
 
-	body, err := request.GetBody()
-	if err != nil {
-		return nil, fmt.Errorf("error getting request body: %w", err)
-	}
-	defer body.Close()
-	payload, err := ioutil.ReadAll(body)
+	defer request.Body.Close()
+	payload, err := ioutil.ReadAll(request.Body)
 	if err != nil {
 		return nil, fmt.Errorf("error reading request body: %w", err)
 	}
@@ -84,7 +81,7 @@ func (w *Interceptor) ExecuteTrigger(request *http.Request) (*http.Response, err
 
 	return &http.Response{
 		Header: request.Header,
-		Body:   request.Body,
+		Body:   ioutil.NopCloser(bytes.NewBuffer(payload)),
 	}, nil
 }
 

pkg/interceptors/github/github.go

@@ -17,6 +17,7 @@ limitations under the License.
 package github
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -46,22 +47,18 @@ func NewInterceptor(gh *triggersv1.GitHubInterceptor, k kubernetes.Interface, ns
 }
 
 func (w *Interceptor) ExecuteTrigger(request *http.Request) (*http.Response, error) {
+	defer request.Body.Close()
+	payload, err := ioutil.ReadAll(request.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read request body: %w", err)
+	}
+
 	// Validate secrets first before anything else, if set
 	if w.GitHub.SecretRef != nil {
 		header := request.Header.Get("X-Hub-Signature")
 		if header == "" {
 			return nil, errors.New("no X-Hub-Signature header set")
 		}
-
-		body, err := request.GetBody()
-		if err != nil {
-			return nil, err
-		}
-		defer body.Close()
-		payload, err := ioutil.ReadAll(body)
-		if err != nil {
-			return nil, err
-		}
 		secretToken, err := interceptors.GetSecretToken(w.KubeClientSet, w.GitHub.SecretRef, w.EventListenerNamespace)
 		if err != nil {
 			return nil, err
@@ -88,6 +85,6 @@ func (w *Interceptor) ExecuteTrigger(request *http.Request) (*http.Response, err
 
 	return &http.Response{
 		Header: request.Header,
-		Body:   request.Body,
+		Body:   ioutil.NopCloser(bytes.NewBuffer(payload)),
 	}, nil
 }

pkg/resources/create.go

@@ -88,7 +88,7 @@ func Create(logger *zap.SugaredLogger, rt json.RawMessage, triggerName, eventID,
 	if name == "" {
 		name = data.GetGenerateName()
 	}
-	logger.Infof("Generating resource: kind: %+v, name: %s", apiResource, name)
+	logger.Infof("Generating resource: kind: %s, name: %s", apiResource, name)
 
 	gvr := schema.GroupVersionResource{
 		Group:    apiResource.Group,

pkg/sink/sink.go

@@ -17,6 +17,7 @@ limitations under the License.
 package sink
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -72,7 +73,6 @@ func (r Sink) HandleEvent(response http.ResponseWriter, request *http.Request) {
 		response.WriteHeader(http.StatusInternalServerError)
 		return
 	}
-
 	event, err := ioutil.ReadAll(request.Body)
 	if err != nil {
 		r.Logger.Errorf("Error reading event body: %s", err)
@@ -158,7 +158,11 @@ func (r Sink) executeInterceptors(t *triggersv1.EventListenerTrigger, in *http.R
 		return event, in.Header, nil
 	}
 
-	request := in
+	// The request body to the first interceptor in the chain should be the received event body.
+	request := &http.Request{
+		Header: in.Header,
+		Body: ioutil.NopCloser(bytes.NewBuffer(event)),
+	}
 	var resp *http.Response
 	for _, i := range t.Interceptors {
 		var interceptor interceptors.Interceptor
@@ -174,7 +178,6 @@ func (r Sink) executeInterceptors(t *triggersv1.EventListenerTrigger, in *http.R
 		default:
 			return nil, nil, fmt.Errorf("unknown interceptor type: %v", i)
 		}
-
 		var err error
 		resp, err = interceptor.ExecuteTrigger(request)
 		if err != nil {
@@ -185,7 +188,7 @@ func (r Sink) executeInterceptors(t *triggersv1.EventListenerTrigger, in *http.R
 		// request chaining.
 		request = &http.Request{
 			Header: resp.Header,
-			Body:   resp.Body,
+			Body:   ioutil.NopCloser(resp.Body),
 		}
 	}
 	payload, err := ioutil.ReadAll(resp.Body)

pkg/sink/sink_test.go

@@ -295,11 +295,11 @@ func TestExecuteInterceptor(t *testing.T) {
 		Interceptors: []*triggersv1.EventInterceptor{a, a},
 	}
 
-	req, err := http.NewRequest(http.MethodPost, "/", bytes.NewBufferString(`{}`))
+	req, err := http.NewRequest(http.MethodPost, "/", nil)
 	if err != nil {
 		t.Fatalf("http.NewRequest: %v", err)
 	}
-	resp, header, err := r.executeInterceptors(trigger, req, nil, "", logger)
+	resp, header, err := r.executeInterceptors(trigger, req, []byte(`{}`), "", logger)
 	if err != nil {
 		t.Fatalf("executeInterceptors: %v", err)
 	}