renaming plugins -> inputs

plugins/inputs/prometheus/prometheus.go

@@ -0,0 +1,103 @@
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"github.com/influxdb/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 inputs.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 inputs.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() inputs.Input {
+		return &Prometheus{}
+	})
+}

plugins/inputs/prometheus/prometheus_test.go

@@ -0,0 +1,55 @@
+package prometheus
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/influxdb/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const sampleTextFormat = `# HELP go_gc_duration_seconds A summary of the GC invocation durations.
+# TYPE go_gc_duration_seconds summary
+go_gc_duration_seconds{quantile="0"} 0.00010425500000000001
+go_gc_duration_seconds{quantile="0.25"} 0.000139108
+go_gc_duration_seconds{quantile="0.5"} 0.00015749400000000002
+go_gc_duration_seconds{quantile="0.75"} 0.000331463
+go_gc_duration_seconds{quantile="1"} 0.000667154
+go_gc_duration_seconds_sum 0.0018183950000000002
+go_gc_duration_seconds_count 7
+# HELP go_goroutines Number of goroutines that currently exist.
+# TYPE go_goroutines gauge
+go_goroutines 15
+`
+
+func TestPrometheusGeneratesMetrics(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintln(w, sampleTextFormat)
+	}))
+	defer ts.Close()
+
+	p := &Prometheus{
+		Urls: []string{ts.URL},
+	}
+
+	var acc testutil.Accumulator
+
+	err := p.Gather(&acc)
+	require.NoError(t, err)
+
+	expected := []struct {
+		name  string
+		value float64
+		tags  map[string]string
+	}{
+		{"prometheus_go_gc_duration_seconds_count", 7, map[string]string{}},
+		{"prometheus_go_goroutines", 15, map[string]string{}},
+	}
+
+	for _, e := range expected {
+		assert.True(t, acc.HasFloatField(e.name, "value"))
+	}
+}