Refactor functions to not be members of Sink 🚰

Just like with reconcilers / controllers, adding functions of as members
of the Sink (or controller) object itself has some downsides: it's hard
to tell what the responsibilities of the functions are and how they are
coupled to the Sink, and it's harder to write more focused unit tests.

I am working on tektoncd#258 in another branch and in that branch I wanted to
make some updates to the unit tests for this logic; it's easier to do if
it's factored out a bit.

There is more factoring we can do here: now that the functions are moved
out of Sink we can make decisions around their interfaces and maybe make
them even more focused and unit testable.

(Though it was a happy surprise to see they were unit tested even though
they were members of Sink!)

pkg/resources/create.go

@@ -0,0 +1,121 @@
+/*
+Copyright 2019 The Tekton Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package resources
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"k8s.io/client-go/dynamic"
+
+	"go.uber.org/zap"
+
+	"golang.org/x/xerrors"
+
+	triggersv1 "github.com/tektoncd/triggers/pkg/apis/triggers/v1alpha1"
+	"github.com/tidwall/sjson"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	discoveryclient "k8s.io/client-go/discovery"
+)
+
+// FindAPIResource returns the APIResource definition using the discovery client c.
+func FindAPIResource(apiVersion, kind string, c discoveryclient.ServerResourcesInterface) (*metav1.APIResource, error) {
+	//resourceList, err := r.DiscoveryClient.ServerResourcesForGroupVersion(apiVersion)
+	resourceList, err := c.ServerResourcesForGroupVersion(apiVersion)
+	if err != nil {
+		return nil, xerrors.Errorf("Error getting kubernetes server resources for apiVersion %s: %s", apiVersion, err)
+	}
+	for _, apiResource := range resourceList.APIResources {
+		if apiResource.Kind != kind {
+			continue
+		}
+		r := &apiResource
+		// Resolve GroupVersion from parent list to have consistent resource identifiers.
+		if r.Version == "" || r.Group == "" {
+			gv, err := schema.ParseGroupVersion(resourceList.GroupVersion)
+			if err != nil {
+				return nil, xerrors.Errorf("error parsing parsing GroupVersion: %v", err)
+			}
+			r.Group = gv.Group
+			r.Version = gv.Version
+		}
+		return r, nil
+	}
+	return nil, xerrors.Errorf("Error could not find resource with apiVersion %s and kind %s", apiVersion, kind)
+}
+
+// Create uses the kubeClient to create the resource defined in the
+// TriggerResourceTemplate and returns any errors with this process
+func Create(logger *zap.SugaredLogger, rt json.RawMessage, triggerName, eventID, elName, elNamespace string, c discoveryclient.ServerResourcesInterface, dc dynamic.Interface) error {
+	rt, err := AddLabels(rt, map[string]string{
+		triggersv1.EventListenerLabelKey: elName,
+		triggersv1.EventIDLabelKey:       eventID,
+		triggersv1.TriggerLabelKey:       triggerName,
+	})
+	if err != nil {
+		return err
+	}
+
+	// Assume the TriggerResourceTemplate is valid (it has an apiVersion and Kind)
+	data := new(unstructured.Unstructured)
+	if err := data.UnmarshalJSON(rt); err != nil {
+		return err
+	}
+
+	namespace := data.GetNamespace()
+	// Default the resource creation to the EventListenerNamespace if not found in the resource template
+	if namespace == "" {
+		namespace = elNamespace
+	}
+
+	// Resolve resource kind to the underlying API Resource type.
+	apiResource, err := FindAPIResource(data.GetAPIVersion(), data.GetKind(), c)
+	if err != nil {
+		return err
+	}
+
+	name := data.GetName()
+	if name == "" {
+		name = data.GetGenerateName()
+	}
+	logger.Infof("Generating resource: kind: %+v, name: %s", apiResource, name)
+
+	gvr := schema.GroupVersionResource{
+		Group:    apiResource.Group,
+		Version:  apiResource.Version,
+		Resource: apiResource.Name,
+	}
+
+	_, err = dc.Resource(gvr).Namespace(namespace).Create(data, metav1.CreateOptions{})
+	return err
+}
+
+// AddLabels adds autogenerated Tekton labels to created resources.
+func AddLabels(rt json.RawMessage, labels map[string]string) (json.RawMessage, error) {
+	var err error
+	for k, v := range labels {
+		l := fmt.Sprintf("metadata.labels.%s/%s", triggersv1.LabelEscape, strings.TrimLeft(k, "/"))
+		rt, err = sjson.SetBytes(rt, l, v)
+		if err != nil {
+			return rt, err
+		}
+	}
+	return rt, err
+}