mirror of
https://github.com/kubernetes-sigs/prometheus-adapter.git
synced 2026-04-06 09:47:54 +00:00
347 lines
11 KiB
Go
347 lines
11 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package provider
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import (
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"context"
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"fmt"
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"time"
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"github.com/golang/glog"
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"github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/provider"
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pmodel "github.com/prometheus/common/model"
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apierr "k8s.io/apimachinery/pkg/api/errors"
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apimeta "k8s.io/apimachinery/pkg/api/meta"
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"k8s.io/apimachinery/pkg/api/resource"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
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"k8s.io/apimachinery/pkg/labels"
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"k8s.io/apimachinery/pkg/runtime"
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"k8s.io/apimachinery/pkg/runtime/schema"
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utilruntime "k8s.io/apimachinery/pkg/util/runtime"
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"k8s.io/apimachinery/pkg/util/wait"
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"k8s.io/client-go/dynamic"
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"k8s.io/metrics/pkg/apis/custom_metrics"
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prom "github.com/directxman12/k8s-prometheus-adapter/pkg/client"
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)
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// Runnable represents something that can be run until told to stop.
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type Runnable interface {
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// Run runs the runnable forever.
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Run()
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// RunUntil runs the runnable until the given channel is closed.
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RunUntil(stopChan <-chan struct{})
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}
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type prometheusProvider struct {
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mapper apimeta.RESTMapper
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kubeClient dynamic.Interface
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promClient prom.Client
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SeriesRegistry
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}
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func NewPrometheusProvider(mapper apimeta.RESTMapper, kubeClient dynamic.Interface, promClient prom.Client, namers []MetricNamer, updateInterval time.Duration) (provider.CustomMetricsProvider, Runnable) {
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lister := &cachingMetricsLister{
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updateInterval: updateInterval,
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promClient: promClient,
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namers: namers,
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SeriesRegistry: &basicSeriesRegistry{
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mapper: mapper,
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},
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}
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return &prometheusProvider{
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mapper: mapper,
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kubeClient: kubeClient,
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promClient: promClient,
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SeriesRegistry: lister,
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}, lister
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}
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func (p *prometheusProvider) metricFor(value pmodel.SampleValue, groupResource schema.GroupResource, namespace string, name string, metricName string) (*custom_metrics.MetricValue, error) {
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kind, err := p.mapper.KindFor(groupResource.WithVersion(""))
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if err != nil {
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return nil, err
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}
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return &custom_metrics.MetricValue{
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DescribedObject: custom_metrics.ObjectReference{
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APIVersion: groupResource.Group + "/" + runtime.APIVersionInternal,
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Kind: kind.Kind,
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Name: name,
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Namespace: namespace,
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},
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MetricName: metricName,
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Timestamp: metav1.Time{time.Now()},
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Value: *resource.NewMilliQuantity(int64(value*1000.0), resource.DecimalSI),
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}, nil
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}
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func (p *prometheusProvider) metricsFor(valueSet pmodel.Vector, info provider.CustomMetricInfo, list runtime.Object) (*custom_metrics.MetricValueList, error) {
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if !apimeta.IsListType(list) {
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return nil, apierr.NewInternalError(fmt.Errorf("result of label selector list operation was not a list"))
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}
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values, found := p.MatchValuesToNames(info, valueSet)
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if !found {
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return nil, provider.NewMetricNotFoundError(info.GroupResource, info.Metric)
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}
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res := []custom_metrics.MetricValue{}
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err := apimeta.EachListItem(list, func(item runtime.Object) error {
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objUnstructured := item.(*unstructured.Unstructured)
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objName := objUnstructured.GetName()
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if _, found := values[objName]; !found {
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return nil
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}
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value, err := p.metricFor(values[objName], info.GroupResource, objUnstructured.GetNamespace(), objName, info.Metric)
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if err != nil {
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return err
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}
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res = append(res, *value)
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return nil
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})
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if err != nil {
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return nil, err
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}
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return &custom_metrics.MetricValueList{
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Items: res,
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}, nil
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}
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func (p *prometheusProvider) buildQuery(info provider.CustomMetricInfo, namespace string, names ...string) (pmodel.Vector, error) {
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query, found := p.QueryForMetric(info, namespace, names...)
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if !found {
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return nil, provider.NewMetricNotFoundError(info.GroupResource, info.Metric)
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}
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// TODO: use an actual context
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queryResults, err := p.promClient.Query(context.TODO(), pmodel.Now(), query)
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if err != nil {
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glog.Errorf("unable to fetch metrics from prometheus: %v", err)
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// don't leak implementation details to the user
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return nil, apierr.NewInternalError(fmt.Errorf("unable to fetch metrics"))
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}
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if queryResults.Type != pmodel.ValVector {
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glog.Errorf("unexpected results from prometheus: expected %s, got %s on results %v", pmodel.ValVector, queryResults.Type, queryResults)
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return nil, apierr.NewInternalError(fmt.Errorf("unable to fetch metrics"))
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}
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return *queryResults.Vector, nil
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}
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func (p *prometheusProvider) getSingle(info provider.CustomMetricInfo, namespace, name string) (*custom_metrics.MetricValue, error) {
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queryResults, err := p.buildQuery(info, namespace, name)
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if err != nil {
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return nil, err
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}
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if len(queryResults) < 1 {
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return nil, provider.NewMetricNotFoundForError(info.GroupResource, info.Metric, name)
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}
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namedValues, found := p.MatchValuesToNames(info, queryResults)
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if !found {
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return nil, provider.NewMetricNotFoundError(info.GroupResource, info.Metric)
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}
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if len(namedValues) > 1 {
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glog.V(2).Infof("Got more than one result (%v results) when fetching metric %s for %q, using the first one with a matching name...", len(queryResults), info.String(), name)
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}
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resultValue, nameFound := namedValues[name]
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if !nameFound {
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glog.Errorf("None of the results returned by when fetching metric %s for %q matched the resource name", info.String(), name)
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return nil, provider.NewMetricNotFoundForError(info.GroupResource, info.Metric, name)
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}
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return p.metricFor(resultValue, info.GroupResource, "", name, info.Metric)
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}
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func (p *prometheusProvider) getMultiple(info provider.CustomMetricInfo, namespace string, selector labels.Selector) (*custom_metrics.MetricValueList, error) {
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fullResources, err := p.mapper.ResourcesFor(info.GroupResource.WithVersion(""))
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if err == nil && len(fullResources) == 0 {
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err = fmt.Errorf("no fully versioned resources known for group-resource %v", info.GroupResource)
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}
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if err != nil {
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glog.Errorf("unable to find preferred version to list matching resource names: %v", err)
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// don't leak implementation details to the user
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return nil, apierr.NewInternalError(fmt.Errorf("unable to list matching resources"))
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}
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var client dynamic.ResourceInterface
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if namespace != "" {
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client = p.kubeClient.Resource(fullResources[0]).Namespace(namespace)
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} else {
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client = p.kubeClient.Resource(fullResources[0])
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}
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// actually list the objects matching the label selector
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matchingObjectsRaw, err := client.List(metav1.ListOptions{LabelSelector: selector.String()})
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if err != nil {
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glog.Errorf("unable to list matching resource names: %v", err)
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// don't leak implementation details to the user
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return nil, apierr.NewInternalError(fmt.Errorf("unable to list matching resources"))
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}
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// make sure we have a list
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if !apimeta.IsListType(matchingObjectsRaw) {
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return nil, apierr.NewInternalError(fmt.Errorf("result of label selector list operation was not a list"))
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}
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// convert a list of objects into the corresponding list of names
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resourceNames := []string{}
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err = apimeta.EachListItem(matchingObjectsRaw, func(item runtime.Object) error {
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objName := item.(*unstructured.Unstructured).GetName()
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resourceNames = append(resourceNames, objName)
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return nil
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})
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// construct the actual query
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queryResults, err := p.buildQuery(info, namespace, resourceNames...)
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if err != nil {
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return nil, err
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}
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return p.metricsFor(queryResults, info, matchingObjectsRaw)
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}
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func (p *prometheusProvider) GetRootScopedMetricByName(groupResource schema.GroupResource, name string, metricName string) (*custom_metrics.MetricValue, error) {
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info := provider.CustomMetricInfo{
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GroupResource: groupResource,
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Metric: metricName,
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Namespaced: false,
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}
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return p.getSingle(info, "", name)
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}
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func (p *prometheusProvider) GetRootScopedMetricBySelector(groupResource schema.GroupResource, selector labels.Selector, metricName string) (*custom_metrics.MetricValueList, error) {
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info := provider.CustomMetricInfo{
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GroupResource: groupResource,
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Metric: metricName,
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Namespaced: false,
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}
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return p.getMultiple(info, "", selector)
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}
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func (p *prometheusProvider) GetNamespacedMetricByName(groupResource schema.GroupResource, namespace string, name string, metricName string) (*custom_metrics.MetricValue, error) {
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info := provider.CustomMetricInfo{
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GroupResource: groupResource,
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Metric: metricName,
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Namespaced: true,
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}
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return p.getSingle(info, namespace, name)
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}
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func (p *prometheusProvider) GetNamespacedMetricBySelector(groupResource schema.GroupResource, namespace string, selector labels.Selector, metricName string) (*custom_metrics.MetricValueList, error) {
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info := provider.CustomMetricInfo{
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GroupResource: groupResource,
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Metric: metricName,
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Namespaced: true,
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}
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return p.getMultiple(info, namespace, selector)
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}
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type cachingMetricsLister struct {
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SeriesRegistry
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promClient prom.Client
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updateInterval time.Duration
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namers []MetricNamer
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}
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func (l *cachingMetricsLister) Run() {
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l.RunUntil(wait.NeverStop)
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}
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func (l *cachingMetricsLister) RunUntil(stopChan <-chan struct{}) {
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go wait.Until(func() {
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if err := l.updateMetrics(); err != nil {
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utilruntime.HandleError(err)
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}
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}, l.updateInterval, stopChan)
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}
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type selectorSeries struct {
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selector prom.Selector
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series []prom.Series
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}
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func (l *cachingMetricsLister) updateMetrics() error {
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startTime := pmodel.Now().Add(-1 * l.updateInterval)
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// don't do duplicate queries when it's just the matchers that change
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seriesCacheByQuery := make(map[prom.Selector][]prom.Series)
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// these can take a while on large clusters, so launch in parallel
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// and don't duplicate
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selectors := make(map[prom.Selector]struct{})
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selectorSeriesChan := make(chan selectorSeries, len(l.namers))
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errs := make(chan error, len(l.namers))
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for _, namer := range l.namers {
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sel := namer.Selector()
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if _, ok := selectors[sel]; ok {
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errs <- nil
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selectorSeriesChan <- selectorSeries{}
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continue
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}
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selectors[sel] = struct{}{}
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go func() {
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series, err := l.promClient.Series(context.TODO(), pmodel.Interval{startTime, 0}, sel)
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if err != nil {
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errs <- fmt.Errorf("unable to fetch metrics for query %q: %v", sel, err)
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return
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}
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errs <- nil
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selectorSeriesChan <- selectorSeries{
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selector: sel,
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series: series,
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}
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}()
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}
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// iterate through, blocking until we've got all results
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for range l.namers {
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if err := <-errs; err != nil {
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return fmt.Errorf("unable to update list of all metrics: %v", err)
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}
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if ss := <-selectorSeriesChan; ss.series != nil {
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seriesCacheByQuery[ss.selector] = ss.series
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}
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}
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close(errs)
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newSeries := make([][]prom.Series, len(l.namers))
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for i, namer := range l.namers {
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series, cached := seriesCacheByQuery[namer.Selector()]
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if !cached {
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return fmt.Errorf("unable to update list of all metrics: no metrics retrieved for query %q", namer.Selector())
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}
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newSeries[i] = namer.FilterSeries(series)
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}
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glog.V(10).Infof("Set available metric list from Prometheus to: %v", newSeries)
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return l.SetSeries(newSeries, l.namers)
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}
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