package prometheus import ( "errors" "fmt" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/plugins/inputs" "github.com/prometheus/common/expfmt" "github.com/prometheus/common/model" "io" "net/http" "sync" ) type Prometheus struct { Urls []string } var sampleConfig = ` ## An array of urls to scrape metrics from. urls = ["http://localhost:9100/metrics"] ` func (r *Prometheus) SampleConfig() string { return sampleConfig } func (r *Prometheus) Description() string { return "Read metrics from one or many prometheus clients" } var ErrProtocolError = errors.New("prometheus protocol error") // Reads stats from all configured servers accumulates stats. // Returns one of the errors encountered while gather stats (if any). func (g *Prometheus) Gather(acc telegraf.Accumulator) error { var wg sync.WaitGroup var outerr error for _, serv := range g.Urls { wg.Add(1) go func(serv string) { defer wg.Done() outerr = g.gatherURL(serv, acc) }(serv) } wg.Wait() return outerr } func (g *Prometheus) gatherURL(url string, acc telegraf.Accumulator) error { resp, err := http.Get(url) if err != nil { return fmt.Errorf("error making HTTP request to %s: %s", url, err) } defer resp.Body.Close() if resp.StatusCode != http.StatusOK { return fmt.Errorf("%s returned HTTP status %s", url, resp.Status) } format := expfmt.ResponseFormat(resp.Header) decoder := expfmt.NewDecoder(resp.Body, format) options := &expfmt.DecodeOptions{ Timestamp: model.Now(), } sampleDecoder := &expfmt.SampleDecoder{ Dec: decoder, Opts: options, } for { var samples model.Vector err := sampleDecoder.Decode(&samples) if err == io.EOF { break } else if err != nil { return fmt.Errorf("error getting processing samples for %s: %s", url, err) } for _, sample := range samples { tags := make(map[string]string) for key, value := range sample.Metric { if key == model.MetricNameLabel { continue } tags[string(key)] = string(value) } acc.Add("prometheus_"+string(sample.Metric[model.MetricNameLabel]), float64(sample.Value), tags) } } return nil } func init() { inputs.Add("prometheus", func() telegraf.Input { return &Prometheus{} }) }