prometheus/storage/remote/opentsdb/client.go
2015-10-03 10:21:43 +02:00

142 lines
3.4 KiB
Go

// Copyright 2013 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 opentsdb
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"math"
"net/http"
"net/url"
"regexp"
"time"
"github.com/prometheus/common/log"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/util/httputil"
)
const (
putEndpoint = "/api/put"
contentTypeJSON = "application/json"
)
var (
illegalCharsRE = regexp.MustCompile(`[^a-zA-Z0-9_\-./]`)
)
// Client allows sending batches of Prometheus samples to OpenTSDB.
type Client struct {
url string
httpClient *http.Client
}
// NewClient creates a new Client.
func NewClient(url string, timeout time.Duration) *Client {
return &Client{
url: url,
httpClient: httputil.NewDeadlineClient(timeout, nil),
}
}
// StoreSamplesRequest is used for building a JSON request for storing samples
// via the OpenTSDB.
type StoreSamplesRequest struct {
Metric TagValue `json:"metric"`
Timestamp int64 `json:"timestamp"`
Value float64 `json:"value"`
Tags map[string]TagValue `json:"tags"`
}
// tagsFromMetric translates Prometheus metric into OpenTSDB tags.
func tagsFromMetric(m model.Metric) map[string]TagValue {
tags := make(map[string]TagValue, len(m)-1)
for l, v := range m {
if l == model.MetricNameLabel {
continue
}
tags[string(l)] = TagValue(v)
}
return tags
}
// Store sends a batch of samples to OpenTSDB via its HTTP API.
func (c *Client) Store(samples model.Samples) error {
reqs := make([]StoreSamplesRequest, 0, len(samples))
for _, s := range samples {
v := float64(s.Value)
if math.IsNaN(v) || math.IsInf(v, 0) {
log.Warnf("cannot send value %f to OpenTSDB, skipping sample %#v", v, s)
continue
}
metric := TagValue(s.Metric[model.MetricNameLabel])
reqs = append(reqs, StoreSamplesRequest{
Metric: metric,
Timestamp: s.Timestamp.Unix(),
Value: v,
Tags: tagsFromMetric(s.Metric),
})
}
u, err := url.Parse(c.url)
if err != nil {
return err
}
u.Path = putEndpoint
buf, err := json.Marshal(reqs)
if err != nil {
return err
}
resp, err := c.httpClient.Post(
u.String(),
contentTypeJSON,
bytes.NewBuffer(buf),
)
if err != nil {
return err
}
defer resp.Body.Close()
// API returns status code 204 for successful writes.
// http://opentsdb.net/docs/build/html/api_http/put.html
if resp.StatusCode == http.StatusNoContent {
return nil
}
// API returns status code 400 on error, encoding error details in the
// response content in JSON.
buf, err = ioutil.ReadAll(resp.Body)
if err != nil {
return err
}
var r map[string]int
if err := json.Unmarshal(buf, &r); err != nil {
return err
}
return fmt.Errorf("failed to write %d samples to OpenTSDB, %d succeeded", r["failed"], r["success"])
}
// Name identifies the client as an OpenTSDB client.
func (c Client) Name() string {
return "opentsdb"
}