Merge pull request #158 from linux-on-ibm-z/cross-compile

Edited Makefile to add cross build support for s390x.

Adding External Metrics Provider

pkg/external-provider/external_series_registry.go

@@ -0,0 +1,109 @@
+package provider
+
+import (
+	"sync"
+
+	"github.com/golang/glog"
+	"github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/provider"
+	apimeta "k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/labels"
+
+	prom "github.com/directxman12/k8s-prometheus-adapter/pkg/client"
+)
+
+// ExternalSeriesRegistry acts as the top-level converter for transforming Kubernetes requests
+// for external metrics into Prometheus queries.
+type ExternalSeriesRegistry interface {
+	// ListAllMetrics lists all metrics known to this registry
+	ListAllMetrics() []provider.ExternalMetricInfo
+	QueryForMetric(namespace string, metricName string, metricSelector labels.Selector) (prom.Selector, bool, error)
+}
+
+// overridableSeriesRegistry is a basic SeriesRegistry
+type externalSeriesRegistry struct {
+	mu sync.RWMutex
+
+	// metrics is the list of all known metrics, ready to return from the API
+	metrics []provider.ExternalMetricInfo
+	// rawMetrics is a lookup from a metric to SeriesConverter for the sake of generating queries
+	rawMetrics map[string]SeriesConverter
+
+	mapper apimeta.RESTMapper
+
+	metricLister MetricListerWithNotification
+}
+
+// NewExternalSeriesRegistry creates an ExternalSeriesRegistry driven by the data from the provided MetricLister.
+func NewExternalSeriesRegistry(lister MetricListerWithNotification, mapper apimeta.RESTMapper) ExternalSeriesRegistry {
+	var registry = externalSeriesRegistry{
+		mapper:       mapper,
+		metricLister: lister,
+		metrics:      make([]provider.ExternalMetricInfo, 0),
+		rawMetrics:   map[string]SeriesConverter{},
+	}
+
+	lister.AddNotificationReceiver(registry.filterAndStoreMetrics)
+
+	return &registry
+}
+
+func (r *externalSeriesRegistry) filterAndStoreMetrics(result MetricUpdateResult) {
+
+	newSeriesSlices := result.series
+	converters := result.converters
+
+	if len(newSeriesSlices) != len(converters) {
+		glog.Errorf("need one set of series per converter")
+	}
+	apiMetricsCache := make([]provider.ExternalMetricInfo, 0)
+	rawMetricsCache := make(map[string]SeriesConverter)
+
+	for i, newSeries := range newSeriesSlices {
+		converter := converters[i]
+		for _, series := range newSeries {
+			identity, err := converter.IdentifySeries(series)
+
+			if err != nil {
+				glog.Errorf("unable to name series %q, skipping: %v", series.String(), err)
+				continue
+			}
+
+			name := identity.name
+			rawMetricsCache[name] = converter
+		}
+	}
+
+	for metricName := range rawMetricsCache {
+		apiMetricsCache = append(apiMetricsCache, provider.ExternalMetricInfo{
+			Metric: metricName,
+		})
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.metrics = apiMetricsCache
+	r.rawMetrics = rawMetricsCache
+}
+
+func (r *externalSeriesRegistry) ListAllMetrics() []provider.ExternalMetricInfo {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+
+	return r.metrics
+}
+
+func (r *externalSeriesRegistry) QueryForMetric(namespace string, metricName string, metricSelector labels.Selector) (prom.Selector, bool, error) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+
+	converter, found := r.rawMetrics[metricName]
+
+	if !found {
+		glog.V(10).Infof("external metric %q not found", metricName)
+		return "", false, nil
+	}
+
+	query, err := converter.QueryForExternalSeries(namespace, metricName, metricSelector)
+	return query, found, err
+}