prometheus/storage/remote/read.go
Julius Volz 8ebeed0b44 remote: Expose ClientConfig type (#3165)
The Client type is already exposed, but can't be used without the config for it
also being exposed. Using the remote.Client from other programs is useful to do
full end-to-end tests of Prometheus's remote protocol against adapter
implementations.
2017-09-14 15:25:09 +02:00

193 lines
5.4 KiB
Go

// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package remote
import (
"fmt"
"sync"
"time"
"github.com/prometheus/common/model"
"golang.org/x/net/context"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/storage/local"
"github.com/prometheus/prometheus/storage/metric"
)
// Reader allows reading from multiple remote sources.
type Reader struct {
mtx sync.Mutex
clients []*Client
externalLabels model.LabelSet
}
// ApplyConfig updates the state as the new config requires.
func (r *Reader) ApplyConfig(conf *config.Config) error {
clients := []*Client{}
for i, rrConf := range conf.RemoteReadConfigs {
c, err := NewClient(i, &ClientConfig{
URL: rrConf.URL,
Timeout: rrConf.RemoteTimeout,
HTTPClientConfig: rrConf.HTTPClientConfig,
})
if err != nil {
return err
}
clients = append(clients, c)
}
r.mtx.Lock()
defer r.mtx.Unlock()
r.clients = clients
r.externalLabels = conf.GlobalConfig.ExternalLabels
return nil
}
// Queriers returns a list of Queriers for the currently configured
// remote read endpoints.
func (r *Reader) Queriers() []local.Querier {
r.mtx.Lock()
defer r.mtx.Unlock()
queriers := make([]local.Querier, 0, len(r.clients))
for _, c := range r.clients {
queriers = append(queriers, &querier{
client: c,
externalLabels: r.externalLabels,
})
}
return queriers
}
// querier is an adapter to make a Client usable as a promql.Querier.
type querier struct {
client *Client
externalLabels model.LabelSet
}
func (q *querier) QueryRange(ctx context.Context, from, through model.Time, matchers ...*metric.LabelMatcher) ([]local.SeriesIterator, error) {
return MatrixToIterators(q.read(ctx, from, through, matchers))
}
func (q *querier) QueryInstant(ctx context.Context, ts model.Time, stalenessDelta time.Duration, matchers ...*metric.LabelMatcher) ([]local.SeriesIterator, error) {
return MatrixToIterators(q.read(ctx, ts.Add(-stalenessDelta), ts, matchers))
}
func (q *querier) read(ctx context.Context, from, through model.Time, matchers metric.LabelMatchers) (model.Matrix, error) {
m, added := q.addExternalLabels(matchers)
res, err := q.client.Read(ctx, from, through, m)
if err != nil {
return nil, err
}
removeLabels(res, added)
err = validateLabelsAndMetricName(res)
if err != nil {
return nil, err
}
return res, err
}
// validateLabelsAndMetricName validates the label names/values and metric names returned from remote read.
func validateLabelsAndMetricName(res model.Matrix) error {
for _, r := range res {
if !model.IsValidMetricName(r.Metric[model.MetricNameLabel]) {
return fmt.Errorf("Invalid metric name: %v", r.Metric[model.MetricNameLabel])
}
for name, value := range r.Metric {
if !name.IsValid() {
return fmt.Errorf("Invalid label name: %v", name)
}
if !value.IsValid() {
return fmt.Errorf("Invalid label value: %v", value)
}
}
}
return nil
}
// addExternalLabels adds matchers for each external label. External labels
// that already have a corresponding user-supplied matcher are skipped, as we
// assume that the user explicitly wants to select a different value for them.
// We return the new set of matchers, along with a map of labels for which
// matchers were added, so that these can later be removed from the result
// time series again.
func (q *querier) addExternalLabels(matchers metric.LabelMatchers) (metric.LabelMatchers, model.LabelSet) {
el := make(model.LabelSet, len(q.externalLabels))
for k, v := range q.externalLabels {
el[k] = v
}
for _, m := range matchers {
if _, ok := el[m.Name]; ok {
delete(el, m.Name)
}
}
for k, v := range el {
m, err := metric.NewLabelMatcher(metric.Equal, k, v)
if err != nil {
panic(err)
}
matchers = append(matchers, m)
}
return matchers, el
}
func removeLabels(m model.Matrix, labels model.LabelSet) {
for _, ss := range m {
for k := range labels {
delete(ss.Metric, k)
}
}
}
// MatrixToIterators returns series iterators for a given matrix.
func MatrixToIterators(m model.Matrix, err error) ([]local.SeriesIterator, error) {
if err != nil {
return nil, err
}
its := make([]local.SeriesIterator, 0, len(m))
for _, ss := range m {
its = append(its, sampleStreamIterator{
ss: ss,
})
}
return its, nil
}
func (q *querier) MetricsForLabelMatchers(ctx context.Context, from, through model.Time, matcherSets ...metric.LabelMatchers) ([]metric.Metric, error) {
// TODO: Implement remote metadata querying.
return nil, nil
}
func (q *querier) LastSampleForLabelMatchers(ctx context.Context, cutoff model.Time, matcherSets ...metric.LabelMatchers) (model.Vector, error) {
// TODO: Implement remote last sample querying.
return nil, nil
}
func (q *querier) LabelValuesForLabelName(ctx context.Context, ln model.LabelName) (model.LabelValues, error) {
// TODO: Implement remote metadata querying.
return nil, nil
}
func (q *querier) Close() error {
return nil
}