telegraf/plugins/inputs/influxdb/influxdb.go

244 lines
5.9 KiB
Go

package influxdb
import (
"encoding/json"
"errors"
"fmt"
"net/http"
"strings"
"sync"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
type InfluxDB struct {
URLs []string `toml:"urls"`
}
func (*InfluxDB) Description() string {
return "Read InfluxDB-formatted JSON metrics from one or more HTTP endpoints"
}
func (*InfluxDB) SampleConfig() string {
return `
## Works with InfluxDB debug endpoints out of the box,
## but other services can use this format too.
## See the influxdb plugin's README for more details.
## Multiple URLs from which to read InfluxDB-formatted JSON
urls = [
"http://localhost:8086/debug/vars"
]
`
}
func (i *InfluxDB) Gather(acc telegraf.Accumulator) error {
errorChannel := make(chan error, len(i.URLs))
var wg sync.WaitGroup
for _, u := range i.URLs {
wg.Add(1)
go func(url string) {
defer wg.Done()
if err := i.gatherURL(acc, url); err != nil {
errorChannel <- fmt.Errorf("[url=%s]: %s", url, err)
}
}(u)
}
wg.Wait()
close(errorChannel)
// If there weren't any errors, we can return nil now.
if len(errorChannel) == 0 {
return nil
}
// There were errors, so join them all together as one big error.
errorStrings := make([]string, 0, len(errorChannel))
for err := range errorChannel {
errorStrings = append(errorStrings, err.Error())
}
return errors.New(strings.Join(errorStrings, "\n"))
}
type point struct {
Name string `json:"name"`
Tags map[string]string `json:"tags"`
Values map[string]interface{} `json:"values"`
}
type memstats struct {
Alloc int64 `json:"Alloc"`
TotalAlloc int64 `json:"TotalAlloc"`
Sys int64 `json:"Sys"`
Lookups int64 `json:"Lookups"`
Mallocs int64 `json:"Mallocs"`
Frees int64 `json:"Frees"`
HeapAlloc int64 `json:"HeapAlloc"`
HeapSys int64 `json:"HeapSys"`
HeapIdle int64 `json:"HeapIdle"`
HeapInuse int64 `json:"HeapInuse"`
HeapReleased int64 `json:"HeapReleased"`
HeapObjects int64 `json:"HeapObjects"`
StackInuse int64 `json:"StackInuse"`
StackSys int64 `json:"StackSys"`
MSpanInuse int64 `json:"MSpanInuse"`
MSpanSys int64 `json:"MSpanSys"`
MCacheInuse int64 `json:"MCacheInuse"`
MCacheSys int64 `json:"MCacheSys"`
BuckHashSys int64 `json:"BuckHashSys"`
GCSys int64 `json:"GCSys"`
OtherSys int64 `json:"OtherSys"`
NextGC int64 `json:"NextGC"`
LastGC int64 `json:"LastGC"`
PauseTotalNs int64 `json:"PauseTotalNs"`
NumGC int64 `json:"NumGC"`
GCCPUFraction float64 `json:"GCCPUFraction"`
}
var tr = &http.Transport{
ResponseHeaderTimeout: time.Duration(3 * time.Second),
}
var client = &http.Client{
Transport: tr,
Timeout: time.Duration(4 * time.Second),
}
// Gathers data from a particular URL
// Parameters:
// acc : The telegraf Accumulator to use
// url : endpoint to send request to
//
// Returns:
// error: Any error that may have occurred
func (i *InfluxDB) gatherURL(
acc telegraf.Accumulator,
url string,
) error {
shardCounter := 0
now := time.Now()
resp, err := client.Get(url)
if err != nil {
return err
}
defer resp.Body.Close()
// It would be nice to be able to decode into a map[string]point, but
// we'll get a decoder error like:
// `json: cannot unmarshal array into Go value of type influxdb.point`
// if any of the values aren't objects.
// To avoid that error, we decode by hand.
dec := json.NewDecoder(resp.Body)
// Parse beginning of object
if t, err := dec.Token(); err != nil {
return err
} else if t != json.Delim('{') {
return errors.New("document root must be a JSON object")
}
// Loop through rest of object
for {
// Nothing left in this object, we're done
if !dec.More() {
break
}
// Read in a string key. We don't do anything with the top-level keys,
// so it's discarded.
key, err := dec.Token()
if err != nil {
return err
}
if key.(string) == "memstats" {
var m memstats
if err := dec.Decode(&m); err != nil {
continue
}
acc.AddFields("influxdb_memstats",
map[string]interface{}{
"alloc": m.Alloc,
"total_alloc": m.TotalAlloc,
"sys": m.Sys,
"lookups": m.Lookups,
"mallocs": m.Mallocs,
"frees": m.Frees,
"heap_alloc": m.HeapAlloc,
"heap_sys": m.HeapSys,
"heap_idle": m.HeapIdle,
"heap_inuse": m.HeapInuse,
"heap_released": m.HeapReleased,
"heap_objects": m.HeapObjects,
"stack_inuse": m.StackInuse,
"stack_sys": m.StackSys,
"mspan_inuse": m.MSpanInuse,
"mspan_sys": m.MSpanSys,
"mcache_inuse": m.MCacheInuse,
"mcache_sys": m.MCacheSys,
"buck_hash_sys": m.BuckHashSys,
"gc_sys": m.GCSys,
"other_sys": m.OtherSys,
"next_gc": m.NextGC,
"last_gc": m.LastGC,
"pause_total_ns": m.PauseTotalNs,
"num_gc": m.NumGC,
"gcc_pu_fraction": m.GCCPUFraction,
},
map[string]string{
"url": url,
})
}
// Attempt to parse a whole object into a point.
// It might be a non-object, like a string or array.
// If we fail to decode it into a point, ignore it and move on.
var p point
if err := dec.Decode(&p); err != nil {
continue
}
// If the object was a point, but was not fully initialized,
// ignore it and move on.
if p.Name == "" || p.Tags == nil || p.Values == nil || len(p.Values) == 0 {
continue
}
if p.Name == "shard" {
shardCounter++
}
// Add a tag to indicate the source of the data.
p.Tags["url"] = url
acc.AddFields(
"influxdb_"+p.Name,
p.Values,
p.Tags,
now,
)
}
acc.AddFields("influxdb",
map[string]interface{}{
"n_shards": shardCounter,
},
nil,
now,
)
return nil
}
func init() {
inputs.Add("influxdb", func() telegraf.Input {
return &InfluxDB{}
})
}