add RethinkDB plugin

plugins/rethinkdb/rethinkdb.go

@@ -0,0 +1,92 @@
+package rethinkdb
+
+import (
+	"fmt"
+	"net/url"
+	"sync"
+
+	"github.com/influxdb/telegraf/plugins"
+
+	"gopkg.in/dancannon/gorethink.v1"
+)
+
+type RethinkDB struct {
+	Servers []string
+}
+
+var sampleConfig = `
+# An array of URI to gather stats about. Specify an ip or hostname
+# with optional port add password. ie rethinkdb://user:auth_key@10.10.3.30:28105,
+# rethinkdb://10.10.3.33:18832, 10.0.0.1:10000, etc.
+#
+# If no servers are specified, then 127.0.0.1 is used as the host and 28015 as the port.
+servers = ["127.0.0.1:28015"]`
+
+func (r *RethinkDB) SampleConfig() string {
+	return sampleConfig
+}
+
+func (r *RethinkDB) Description() string {
+	return "Read metrics from one or many RethinkDB servers"
+}
+
+var localhost = &Server{Url: &url.URL{Host: "127.0.0.1:28015"}}
+
+// Reads stats from all configured servers accumulates stats.
+// Returns one of the errors encountered while gather stats (if any).
+func (r *RethinkDB) Gather(acc plugins.Accumulator) error {
+	if len(r.Servers) == 0 {
+		r.gatherServer(localhost, acc)
+		return nil
+	}
+
+	var wg sync.WaitGroup
+
+	var outerr error
+
+	for _, serv := range r.Servers {
+		u, err := url.Parse(serv)
+		if err != nil {
+			return fmt.Errorf("Unable to parse to address '%s': %s", serv, err)
+		} else if u.Scheme == "" {
+			// fallback to simple string based address (i.e. "10.0.0.1:10000")
+			u.Host = serv
+		}
+		wg.Add(1)
+		go func(serv string) {
+			defer wg.Done()
+			outerr = r.gatherServer(&Server{Url: u}, acc)
+		}(serv)
+	}
+
+	wg.Wait()
+
+	return outerr
+}
+
+func (r *RethinkDB) gatherServer(server *Server, acc plugins.Accumulator) error {
+	var err error
+	connectOpts := gorethink.ConnectOpts{
+		Address:       server.Url.Host,
+		DiscoverHosts: false,
+	}
+	if server.Url.User != nil {
+		pwd, set := server.Url.User.Password()
+		if set && pwd != "" {
+			connectOpts.AuthKey = pwd
+		}
+	}
+	server.session, err = gorethink.Connect(connectOpts)
+	if err != nil {
+		return fmt.Errorf("Unable to connect to RethinkDB, %s\n", err.Error())
+	}
+	defer server.session.Close()
+
+	return server.gatherData(acc)
+}
+
+func init() {
+	plugins.Add("rethinkdb", func() plugins.Plugin {
+		return &RethinkDB{}
+	})
+}