fix sink crashloop when upgrading from 0.1 to 0.2

The crashloop is due to 2 reasons:
1. We deprecated and removed the `params` field from the EventListener. So, when the reconciler tries to  unmarshal an old EventListener, it fails since it cannot parse the deleted `params` field.

2. The new event listener sink image expects `/etc/config-logging` to be mounted. However the reconciler code does not add the `volumeMount` for any existing sink deployments. So, the new pods go into a crashloop

To fix this, this commit does the following:
1. Add back the `params` field. Also, update the mutating webhook to delete any set `params` field in existing eventlisteners.
2. Add volumeMount for existing deployments if not present.

Signed-off-by: Dibyo Mukherjee <dibyo@google.com>

pkg/apis/triggers/v1alpha1/event_listener_defaults.go

@@ -12,6 +12,7 @@ func (el *EventListener) SetDefaults(ctx context.Context) {
 			t := &el.Spec.Triggers[i]
 			upgradeBinding(t)
 			upgradeInterceptor(t)
+			removeParams(t)
 		}
 	}
 }
@@ -41,3 +42,9 @@ func upgradeInterceptor(t *EventListenerTrigger) {
 		t.DeprecatedInterceptor = nil
 	}
 }
+
+func removeParams(t *EventListenerTrigger) {
+	if t.DeprecatedParams != nil {
+		t.DeprecatedParams = nil
+	}
+}

pkg/apis/triggers/v1alpha1/event_listener_defaults_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	pipelinev1 "github.com/tektoncd/pipeline/pkg/apis/pipeline/v1alpha1"
 	"github.com/tektoncd/triggers/pkg/apis/triggers/v1alpha1"
 )
 
@@ -141,8 +142,28 @@ func TestEventListenerSetDefaults(t *testing.T) {
 				},
 			},
 			wc: v1alpha1.WithUpgradeViaDefaulting,
-		},
-	}
+		}, {
+			name: "with upgrade context - deprecated params",
+			in: &v1alpha1.EventListener{
+				Spec: v1alpha1.EventListenerSpec{
+					Triggers: []v1alpha1.EventListenerTrigger{{
+						DeprecatedParams: []pipelinev1.Param{{
+							Name: "param-name",
+							Value: pipelinev1.ArrayOrString{
+								Type:      "string",
+								StringVal: "static",
+							},
+						},
+						}},
+					}},
+			},
+			want: &v1alpha1.EventListener{
+				Spec: v1alpha1.EventListenerSpec{
+					Triggers: []v1alpha1.EventListenerTrigger{{}},
+				},
+			},
+			wc: v1alpha1.WithUpgradeViaDefaulting,
+		}}
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			got := tc.in

pkg/apis/triggers/v1alpha1/event_listener_types.go

@@ -74,6 +74,10 @@ type EventListenerTrigger struct {
 
 	// TODO(#248): Remove this before 0.3 release.
 	DeprecatedBinding *EventListenerBinding `json:"binding,omitempty"`
+
+	// TODO(#): Remove this before 0.3 release
+	// DEPRECATED: Use TriggerBindings with static values instead
+	DeprecatedParams []pipelinev1.Param `json:"params,omitempty"`
 }
 
 // EventInterceptor provides a hook to intercept and pre-process events

pkg/reconciler/v1alpha1/eventlistener/eventlistener.go

@@ -354,6 +354,10 @@ func (c *Reconciler) reconcileDeployment(el *v1alpha1.EventListener) error {
 				existingDeployment.Spec.Template.Spec.Containers[0].Command = nil
 				updated = true
 			}
+			if len(existingDeployment.Spec.Template.Spec.Containers[0].VolumeMounts) == 0 {
+				existingDeployment.Spec.Template.Spec.Containers[0].VolumeMounts = container.VolumeMounts
+				updated = true
+			}
 		}
 		if updated {
 			if _, err := c.KubeClientSet.AppsV1().Deployments(el.Namespace).Update(existingDeployment); err != nil {

pkg/reconciler/v1alpha1/eventlistener/eventlistener_test.go

@@ -260,6 +260,7 @@ func Test_reconcileDeployment(t *testing.T) {
 	eventListener4.Spec.ServiceAccountName = updatedSa
 
 	var replicas int32 = 1
+	// deployment1 == initial deployment
 	deployment1 := &appsv1.Deployment{
 		ObjectMeta: generateObjectMeta(eventListener0),
 		Spec: appsv1.DeploymentSpec{
@@ -329,18 +330,23 @@ func Test_reconcileDeployment(t *testing.T) {
 		},
 	}
 
+	// deployment 2 == initial deployment + labels from eventListener
 	deployment2 := deployment1.DeepCopy()
 	deployment2.Labels = mergeLabels(generatedLabels, updateLabel)
 	deployment2.Spec.Selector.MatchLabels = mergeLabels(generatedLabels, updateLabel)
 	deployment2.Spec.Template.Labels = mergeLabels(generatedLabels, updateLabel)
 
+	// deployment 3 == initial deployment + updated replicas
 	deployment3 := deployment1.DeepCopy()
 	var updateReplicas int32 = 5
 	deployment3.Spec.Replicas = &updateReplicas
 
 	deployment4 := deployment1.DeepCopy()
 	deployment4.Spec.Template.Spec.ServiceAccountName = updatedSa
 
+	deploymentMissingVolumeMount := deployment1.DeepCopy()
+	deploymentMissingVolumeMount.Spec.Template.Spec.Containers[0].VolumeMounts = nil
+
 	tests := []struct {
 		name           string
 		startResources test.Resources
@@ -422,6 +428,18 @@ func Test_reconcileDeployment(t *testing.T) {
 				EventListeners: []*v1alpha1.EventListener{eventListener4},
 				Deployments:    []*appsv1.Deployment{deployment4},
 			},
+		}, {
+			name: "eventlistener-config-volume-mount-update",
+			startResources: test.Resources{
+				Namespaces:     []*corev1.Namespace{namespaceResource},
+				EventListeners: []*v1alpha1.EventListener{eventListener2},
+				Deployments:    []*appsv1.Deployment{deploymentMissingVolumeMount},
+			},
+			endResources: test.Resources{
+				Namespaces:     []*corev1.Namespace{namespaceResource},
+				EventListeners: []*v1alpha1.EventListener{eventListener2},
+				Deployments:    []*appsv1.Deployment{deployment2},
+			},
 		},
 	}
 	for i := range tests {