prometheus-adapter/pkg/custom-provider/external_provider.go
2018-06-28 22:08:21 -04:00

87 lines
3.2 KiB
Go

package provider
import (
"context"
"time"
pmodel "github.com/prometheus/common/model"
conv "github.com/directxman12/k8s-prometheus-adapter/pkg/custom-provider/metric-converter"
"github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/provider"
apimeta "k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/client-go/dynamic"
"k8s.io/metrics/pkg/apis/external_metrics"
prom "github.com/directxman12/k8s-prometheus-adapter/pkg/client"
)
//TODO: Make sure everything has the proper licensing disclosure at the top.
//TODO: I'd like to move these files into another directory, but the compiler was giving me
//some static around unexported types. I'm going to leave things as-is for now, but it
//might be worthwhile to, once the shared components are discovered, move some things around.
//TODO: Some of these members may not be necessary.
//Some of them are definitely duplicated between the
//external and custom providers. They should probably share
//the same instances of these objects (especially the SeriesRegistry)
//to cut down on unnecessary chatter/bookkeeping.
type externalPrometheusProvider struct {
mapper apimeta.RESTMapper
kubeClient dynamic.Interface
promClient prom.Client
queryBuilder ExternalMetricQueryBuilder
metricConverter conv.MetricConverter
SeriesRegistry
}
//TODO: It probably makes more sense to, once this is functional and complete, roll the
//prometheusProvider and externalPrometheusProvider up into a single type
//that implements both interfaces or provide a thin wrapper that composes them.
//Just glancing at start.go looks like it would be much more straightforward
//to do one of those two things instead of trying to run the two providers
//independently.
func NewExternalPrometheusProvider(mapper apimeta.RESTMapper, kubeClient dynamic.Interface, promClient prom.Client, namers []MetricNamer, updateInterval time.Duration, queryBuilder ExternalMetricQueryBuilder, metricConverter conv.MetricConverter) (provider.ExternalMetricsProvider, Runnable) {
lister := &cachingMetricsLister{
updateInterval: updateInterval,
promClient: promClient,
namers: namers,
SeriesRegistry: &basicSeriesRegistry{
mapper: mapper,
},
}
return &externalPrometheusProvider{
mapper: mapper,
kubeClient: kubeClient,
promClient: promClient,
metricConverter: metricConverter,
SeriesRegistry: lister,
}, lister
}
func (p *externalPrometheusProvider) GetExternalMetric(namespace string, metricName string, metricSelector labels.Selector) (*external_metrics.ExternalMetricValueList, error) {
query := p.queryBuilder.BuildPrometheusQuery(namespace, metricName, metricSelector)
selector := prom.Selector(query)
//TODO: I don't yet know what a context is, but apparently I should use a real one.
queryResults, err := p.promClient.Query(context.TODO(), pmodel.Now(), selector)
if err != nil {
//TODO: Is this how folks normally deal w/ errors? Just propagate them upwards?
//I should go look at what the customProvider does.
return nil, err
}
return p.metricConverter.Convert(queryResults)
}
func (p *externalPrometheusProvider) ListAllExternalMetrics() []provider.ExternalMetricInfo {
//TODO: Provide a real response.
return nil
}