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{} }) }