From fc8ef3bf3ac8bdc0a3f70b572b15d3b0ac050f74 Mon Sep 17 00:00:00 2001
From: Alvaro Morales <alvaro@asana.com>
Date: Tue, 4 Aug 2015 14:48:13 -0700
Subject: [PATCH] Add httpjson plugin

---
 plugins/all/all.go           |   1 +
 plugins/httpjson/httpjson.go | 110 +++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)
 create mode 100644 plugins/httpjson/httpjson.go

diff --git a/plugins/all/all.go b/plugins/all/all.go
index bc610c39c..8670c3d8b 100644
--- a/plugins/all/all.go
+++ b/plugins/all/all.go
@@ -5,6 +5,7 @@ import (
 	_ "github.com/influxdb/telegraf/plugins/elasticsearch"
 	_ "github.com/influxdb/telegraf/plugins/exec"
 	_ "github.com/influxdb/telegraf/plugins/haproxy"
+	_ "github.com/influxdb/telegraf/plugins/httpjson"
 	_ "github.com/influxdb/telegraf/plugins/kafka_consumer"
 	_ "github.com/influxdb/telegraf/plugins/leofs"
 	_ "github.com/influxdb/telegraf/plugins/lustre2"
diff --git a/plugins/httpjson/httpjson.go b/plugins/httpjson/httpjson.go
new file mode 100644
index 000000000..90af0c1a7
--- /dev/null
+++ b/plugins/httpjson/httpjson.go
@@ -0,0 +1,110 @@
+package httpjson
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/bitly/go-simplejson"
+	"github.com/influxdb/telegraf/plugins"
+	"net/http"
+	"sync"
+)
+
+type HttpJson struct {
+	Servers      []string
+	Measurements map[string]string
+	Method       string
+	Foo          string
+	client       *http.Client
+}
+
+var sampleConfig = `
+# stats url endpoint
+servers = ["http://localhost:5000"]
+
+# a name for server(s)
+foo = "mycluster"
+
+# HTTP method (GET or POST)
+method = "GET"
+
+# Map of key transforms # TODO describe
+[httpjson.measurements]
+stats_measurements_measurement = "my_measurement"
+`
+
+func (h *HttpJson) SampleConfig() string {
+	return sampleConfig
+}
+
+func (h *HttpJson) Description() string {
+	return "Read flattened metrics from one or more JSON HTTP endpoints"
+}
+
+func (h *HttpJson) Gather(acc plugins.Accumulator) error {
+	var wg sync.WaitGroup
+
+	var outerr error
+
+	for _, server := range h.Servers {
+		wg.Add(1)
+		go func(server string) {
+			defer wg.Done()
+			outerr = h.gatherServer(server, acc)
+		}(server)
+	}
+
+	wg.Wait()
+
+	return outerr
+}
+
+func (h *HttpJson) gatherServer(url string, acc plugins.Accumulator) error {
+	r, err := h.client.Get(url)
+	if err != nil {
+		return err
+	}
+
+	if r.StatusCode != http.StatusOK {
+		return fmt.Errorf("httpjson: server '%s' responded with status-code %d, expected %d", r.StatusCode, http.StatusOK)
+	}
+
+	response, err := simplejson.NewFromReader(r.Body)
+
+	if err != nil {
+		return err
+	}
+
+	tags := map[string]string{
+		"server": url,
+	}
+
+	return parseResponse(acc, h.Foo, tags, response.Interface(), h.Measurements)
+}
+
+func parseResponse(acc plugins.Accumulator, prefix string, tags map[string]string, v interface{}, measurements map[string]string) error {
+	switch t := v.(type) {
+	case map[string]interface{}:
+		for k, v := range t {
+			if err := parseResponse(acc, prefix+"_"+k, tags, v, measurements); err != nil {
+				return err
+			}
+		}
+	case json.Number:
+		if transform, ok := measurements[prefix]; ok {
+			prefix = transform
+		}
+		acc.Add(prefix, t, tags)
+	case bool, string, []interface{}:
+		// ignored types
+		return nil
+	default:
+		return fmt.Errorf("httpjson: got unexpected type %T with value %v (%s)", t, v, prefix)
+	}
+	return nil
+}
+
+func init() {
+	plugins.Add("httpjson", func() plugins.Plugin {
+		return &HttpJson{client: http.DefaultClient}
+	})
+}