Add new line protocol parser and serializer, influxdb output (#3924)

plugins/outputs/influxdb/udp.go

@@ -0,0 +1,116 @@
+package influxdb
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/url"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/serializers"
+	"github.com/influxdata/telegraf/plugins/serializers/influx"
+)
+
+const (
+	// DefaultMaxPayloadSize is the maximum length of the UDP data payload
+	DefaultMaxPayloadSize = 512
+)
+
+type Dialer interface {
+	DialContext(ctx context.Context, network, address string) (Conn, error)
+}
+
+type Conn interface {
+	Write(b []byte) (int, error)
+	Close() error
+}
+
+type UDPConfig struct {
+	MaxPayloadSize int
+	URL            *url.URL
+	Serializer     serializers.Serializer
+	Dialer         Dialer
+}
+
+func NewUDPClient(config *UDPConfig) (*udpClient, error) {
+	if config.URL == nil {
+		return nil, ErrMissingURL
+	}
+
+	size := config.MaxPayloadSize
+	if size == 0 {
+		size = DefaultMaxPayloadSize
+	}
+
+	serializer := config.Serializer
+	if serializer == nil {
+		s := influx.NewSerializer()
+		s.SetMaxLineBytes(config.MaxPayloadSize)
+		serializer = s
+	}
+
+	dialer := config.Dialer
+	if dialer == nil {
+		dialer = &netDialer{net.Dialer{}}
+	}
+
+	client := &udpClient{
+		url:        config.URL,
+		serializer: serializer,
+		dialer:     dialer,
+	}
+	return client, nil
+}
+
+type udpClient struct {
+	conn       Conn
+	dialer     Dialer
+	serializer serializers.Serializer
+	url        *url.URL
+}
+
+func (c *udpClient) URL() string {
+	return c.url.String()
+}
+
+func (c *udpClient) Database() string {
+	return ""
+}
+
+func (c *udpClient) Write(ctx context.Context, metrics []telegraf.Metric) error {
+	if c.conn == nil {
+		conn, err := c.dialer.DialContext(ctx, c.url.Scheme, c.url.Host)
+		if err != nil {
+			return fmt.Errorf("error dialing address [%s]: %s", c.url, err)
+		}
+		c.conn = conn
+	}
+
+	for _, metric := range metrics {
+		octets, err := c.serializer.Serialize(metric)
+		if err != nil {
+			return fmt.Errorf("could not serialize metric: %v", err)
+		}
+
+		_, err = c.conn.Write(octets)
+		if err != nil {
+			c.conn.Close()
+			c.conn = nil
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *udpClient) CreateDatabase(ctx context.Context) error {
+	return nil
+}
+
+type netDialer struct {
+	net.Dialer
+}
+
+func (d *netDialer) DialContext(ctx context.Context, network, address string) (Conn, error) {
+	return d.Dialer.DialContext(ctx, network, address)
+}