Add new resources, scale with API (#92)

Can now manage:
- replicasets
- replicationcontrollers
- statefulsets

Scaling now occurs through the scaling API,
rather than manipulating replica count on
resources.

Fix issue with match selector being incorrectly
used, did not match correctly.

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Added
 - Support for other entrypoints other than `/bin/sh`, can specify an entrypoint for the shell command method.
+### Changed
+- Can scale ReplicaSets, ReplicationControllers and StatefulSets alongside Deployments.
+- ResourceMetrics fields have `resourceName` and `resource` rather than `deploymentName` and `deployment`. In JSON this means that only the resource name will be exposed via field `resource`.
+- Uses scaling API rather than manually adjusting replica count on resource.
+- Matches using match selector rather than incorrectly using resource labels and building a different selector.
 
 ## [v0.8.0] - 2019-12-17
 ### Added

api/api.go

@@ -29,22 +29,12 @@ import (
 	"github.com/jthomperoo/custom-pod-autoscaler/config"
 	"github.com/jthomperoo/custom-pod-autoscaler/evaluate"
 	"github.com/jthomperoo/custom-pod-autoscaler/metric"
-	appsv1 "k8s.io/api/apps/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/client-go/kubernetes"
+	"github.com/jthomperoo/custom-pod-autoscaler/resourceclient"
 )
 
 // RunType api marks the metric gathering/evaluation as running during an API request
 const RunType = "api"
 
-type getMetricer interface {
-	GetMetrics(deployment *appsv1.Deployment) (*metric.ResourceMetrics, error)
-}
-
-type getEvaluationer interface {
-	GetEvaluation(resourceMetrics *metric.ResourceMetrics) (*evaluate.Evaluation, error)
-}
-
 // Error is an error response from the API, with the status code and an error message
 type Error struct {
 	Message string `json:"message"`
@@ -55,9 +45,9 @@ type Error struct {
 type API struct {
 	Router          chi.Router
 	Config          *config.Config
-	Clientset       kubernetes.Interface
-	GetMetricer     getMetricer
-	GetEvaluationer getEvaluationer
+	Client          resourceclient.Client
+	GetMetricer     metric.GetMetricer
+	GetEvaluationer evaluate.GetEvaluationer
 }
 
 // Routes sets up routing for the API
@@ -70,17 +60,18 @@ func (api *API) Routes() {
 }
 
 func (api *API) getMetrics(w http.ResponseWriter, r *http.Request) {
-	// Get deployments being managed
-	deployment, err := api.Clientset.AppsV1().Deployments(api.Config.Namespace).Get(api.Config.ScaleTargetRef.Name, metav1.GetOptions{})
+	// Get resource being managed
+	resource, err := api.Client.Get(api.Config.ScaleTargetRef.APIVersion, api.Config.ScaleTargetRef.Kind, api.Config.ScaleTargetRef.Name, api.Config.Namespace)
 	if err != nil {
 		apiError(w, &Error{
 			err.Error(),
 			http.StatusInternalServerError,
 		})
 		return
 	}
+
 	// Get metrics
-	metrics, err := api.GetMetricer.GetMetrics(deployment)
+	metrics, err := api.GetMetricer.GetMetrics(resource)
 	if err != nil {
 		apiError(w, &Error{
 			err.Error(),
@@ -101,17 +92,18 @@ func (api *API) getMetrics(w http.ResponseWriter, r *http.Request) {
 }
 
 func (api *API) getEvaluation(w http.ResponseWriter, r *http.Request) {
-	// Get deployments being managed
-	deployment, err := api.Clientset.AppsV1().Deployments(api.Config.Namespace).Get(api.Config.ScaleTargetRef.Name, metav1.GetOptions{})
+	// Get resource being managed
+	resource, err := api.Client.Get(api.Config.ScaleTargetRef.APIVersion, api.Config.ScaleTargetRef.Kind, api.Config.ScaleTargetRef.Name, api.Config.Namespace)
 	if err != nil {
 		apiError(w, &Error{
 			err.Error(),
 			http.StatusInternalServerError,
 		})
 		return
 	}
+
 	// Get metrics
-	metrics, err := api.GetMetricer.GetMetrics(deployment)
+	metrics, err := api.GetMetricer.GetMetrics(resource)
 	if err != nil {
 		apiError(w, &Error{
 			err.Error(),