Refactor to remove duplicate code from boilerplate

This commit switches to using the boilerplate versions of
a couple different utilities, including the metric info normalization
and the common error types.

pkg/custom-provider/metric_namer.go

@@ -127,7 +127,7 @@ func (r *basicSeriesRegistry) QueryForMetric(metricInfo provider.MetricInfo, nam
 		return 0, "", "", false
 	}
 
-	metricInfo, singularResource, err := r.namer.normalizeInfo(metricInfo)
+	metricInfo, singularResource, err := metricInfo.Normalized(r.namer.mapper)
 	if err != nil {
 		glog.Errorf("unable to normalize group resource while producing a query: %v", err)
 		return 0, "", "", false
@@ -167,7 +167,7 @@ func (r *basicSeriesRegistry) MatchValuesToNames(metricInfo provider.MetricInfo,
 	r.mu.RLock()
 	defer r.mu.RUnlock()
 
-	metricInfo, singularResource, err := r.namer.normalizeInfo(metricInfo)
+	metricInfo, singularResource, err := metricInfo.Normalized(r.namer.mapper)
 	if err != nil {
 		glog.Errorf("unable to normalize group resource while matching values to names: %v", err)
 		return nil, false
@@ -212,24 +212,6 @@ type seriesSpec struct {
 	kind SeriesType
 }
 
-// normalizeInfo takes in some metricInfo an "normalizes" it to ensure a common GroupResource form.
-func (r *metricNamer) normalizeInfo(metricInfo provider.MetricInfo) (provider.MetricInfo, string, error) {
-	// NB: we need to "normalize" the metricInfo's GroupResource so we have a consistent pluralization, etc
-	// TODO: move this to the boilerplate
-	normalizedGroupRes, err := r.mapper.ResourceFor(metricInfo.GroupResource.WithVersion(""))
-	if err != nil {
-		return provider.MetricInfo{}, "", err
-	}
-	metricInfo.GroupResource = normalizedGroupRes.GroupResource()
-
-	singularResource, err := r.mapper.ResourceSingularizer(metricInfo.GroupResource.Resource)
-	if err != nil {
-		return provider.MetricInfo{}, "", err
-	}
-
-	return metricInfo, singularResource, nil
-}
-
 // processContainerSeries performs special work to extract metric definitions
 // from cAdvisor-sourced container metrics, which don't particularly follow any useful conventions consistently.
 func (n *metricNamer) processContainerSeries(series prom.Series, infos map[provider.MetricInfo]seriesInfo) {
@@ -323,7 +305,7 @@ func (n *metricNamer) processRootScopedSeries(series prom.Series, infos map[prov
 // going through each label, checking to see if it corresponds to a known resource.  For instance,
 // a series `ingress_http_hits_total{pod="foo",service="bar",ingress="baz",namespace="ns"}`
 // would return three GroupResources: "pods", "services", and "ingresses".
-// Returned MetricInfo is equilavent to the "normalized" info produced by normalizeInfo.
+// Returned MetricInfo is equilavent to the "normalized" info produced by metricInfo.Normalized.
 func (n *metricNamer) groupResourcesFromSeries(series prom.Series) ([]schema.GroupResource, error) {
 	var res []schema.GroupResource
 	for label := range series.Labels {

pkg/custom-provider/provider.go

@@ -20,7 +20,6 @@ import (
 	"context"
 	"fmt"
 	"github.com/golang/glog"
-	"net/http"
 	"time"
 
 	"github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/provider"
@@ -43,28 +42,6 @@ import (
 	prom "github.com/directxman12/k8s-prometheus-adapter/pkg/client"
 )
 
-// newMetricNotFoundError returns a StatusError indicating the given metric could not be found.
-// It is similar to NewNotFound, but more specialized
-func newMetricNotFoundError(resource schema.GroupResource, metricName string) *apierr.StatusError {
-	return &apierr.StatusError{metav1.Status{
-		Status:  metav1.StatusFailure,
-		Code:    int32(http.StatusNotFound),
-		Reason:  metav1.StatusReasonNotFound,
-		Message: fmt.Sprintf("the server could not find the metric %s for %s", metricName, resource.String()),
-	}}
-}
-
-// newMetricNotFoundForError returns a StatusError indicating the given metric could not be found for
-// the given named object. It is similar to NewNotFound, but more specialized
-func newMetricNotFoundForError(resource schema.GroupResource, metricName string, resourceName string) *apierr.StatusError {
-	return &apierr.StatusError{metav1.Status{
-		Status:  metav1.StatusFailure,
-		Code:    int32(http.StatusNotFound),
-		Reason:  metav1.StatusReasonNotFound,
-		Message: fmt.Sprintf("the server could not find the metric %s for %s %s", metricName, resource.String(), resourceName),
-	}}
-}
-
 type prometheusProvider struct {
 	mapper     apimeta.RESTMapper
 	kubeClient dynamic.ClientPool
@@ -128,7 +105,7 @@ func (p *prometheusProvider) metricsFor(valueSet pmodel.Vector, info provider.Me
 
 	values, found := p.MatchValuesToNames(info, valueSet)
 	if !found {
-		return nil, newMetricNotFoundError(info.GroupResource, info.Metric)
+		return nil, provider.NewMetricNotFoundError(info.GroupResource, info.Metric)
 	}
 	res := []custom_metrics.MetricValue{}
 
@@ -158,7 +135,7 @@ func (p *prometheusProvider) metricsFor(valueSet pmodel.Vector, info provider.Me
 func (p *prometheusProvider) buildQuery(info provider.MetricInfo, namespace string, names ...string) (pmodel.Vector, error) {
 	kind, baseQuery, groupBy, found := p.QueryForMetric(info, namespace, names...)
 	if !found {
-		return nil, newMetricNotFoundError(info.GroupResource, info.Metric)
+		return nil, provider.NewMetricNotFoundError(info.GroupResource, info.Metric)
 	}
 
 	fullQuery := baseQuery
@@ -200,12 +177,12 @@ func (p *prometheusProvider) getSingle(info provider.MetricInfo, namespace, name
 	}
 
 	if len(queryResults) < 1 {
-		return nil, newMetricNotFoundForError(info.GroupResource, info.Metric, name)
+		return nil, provider.NewMetricNotFoundForError(info.GroupResource, info.Metric, name)
 	}
 
 	namedValues, found := p.MatchValuesToNames(info, queryResults)
 	if !found {
-		return nil, newMetricNotFoundError(info.GroupResource, info.Metric)
+		return nil, provider.NewMetricNotFoundError(info.GroupResource, info.Metric)
 	}
 
 	if len(namedValues) > 1 {
@@ -215,7 +192,7 @@ func (p *prometheusProvider) getSingle(info provider.MetricInfo, namespace, name
 	resultValue, nameFound := namedValues[name]
 	if !nameFound {
 		glog.Errorf("None of the results returned by when fetching metric %s for %q matched the resource name", info.String(), name)
-		return nil, newMetricNotFoundForError(info.GroupResource, info.Metric, name)
+		return nil, provider.NewMetricNotFoundForError(info.GroupResource, info.Metric, name)
 	}
 
 	return p.metricFor(resultValue, info.GroupResource, "", name, info.Metric)