Add InfluxDB support for traefik metrics

vendor/github.com/influxdata/influxdb/client/v2/udp.go

@@ -0,0 +1,112 @@
+package client
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"time"
+)
+
+const (
+	// UDPPayloadSize is a reasonable default payload size for UDP packets that
+	// could be travelling over the internet.
+	UDPPayloadSize = 512
+)
+
+// UDPConfig is the config data needed to create a UDP Client.
+type UDPConfig struct {
+	// Addr should be of the form "host:port"
+	// or "[ipv6-host%zone]:port".
+	Addr string
+
+	// PayloadSize is the maximum size of a UDP client message, optional
+	// Tune this based on your network. Defaults to UDPPayloadSize.
+	PayloadSize int
+}
+
+// NewUDPClient returns a client interface for writing to an InfluxDB UDP
+// service from the given config.
+func NewUDPClient(conf UDPConfig) (Client, error) {
+	var udpAddr *net.UDPAddr
+	udpAddr, err := net.ResolveUDPAddr("udp", conf.Addr)
+	if err != nil {
+		return nil, err
+	}
+
+	conn, err := net.DialUDP("udp", nil, udpAddr)
+	if err != nil {
+		return nil, err
+	}
+
+	payloadSize := conf.PayloadSize
+	if payloadSize == 0 {
+		payloadSize = UDPPayloadSize
+	}
+
+	return &udpclient{
+		conn:        conn,
+		payloadSize: payloadSize,
+	}, nil
+}
+
+// Close releases the udpclient's resources.
+func (uc *udpclient) Close() error {
+	return uc.conn.Close()
+}
+
+type udpclient struct {
+	conn        io.WriteCloser
+	payloadSize int
+}
+
+func (uc *udpclient) Write(bp BatchPoints) error {
+	var b = make([]byte, 0, uc.payloadSize) // initial buffer size, it will grow as needed
+	var d, _ = time.ParseDuration("1" + bp.Precision())
+
+	var delayedError error
+
+	var checkBuffer = func(n int) {
+		if len(b) > 0 && len(b)+n > uc.payloadSize {
+			if _, err := uc.conn.Write(b); err != nil {
+				delayedError = err
+			}
+			b = b[:0]
+		}
+	}
+
+	for _, p := range bp.Points() {
+		p.pt.Round(d)
+		pointSize := p.pt.StringSize() + 1 // include newline in size
+		//point := p.pt.RoundedString(d) + "\n"
+
+		checkBuffer(pointSize)
+
+		if p.Time().IsZero() || pointSize <= uc.payloadSize {
+			b = p.pt.AppendString(b)
+			b = append(b, '\n')
+			continue
+		}
+
+		points := p.pt.Split(uc.payloadSize - 1) // account for newline character
+		for _, sp := range points {
+			checkBuffer(sp.StringSize() + 1)
+			b = sp.AppendString(b)
+			b = append(b, '\n')
+		}
+	}
+
+	if len(b) > 0 {
+		if _, err := uc.conn.Write(b); err != nil {
+			return err
+		}
+	}
+	return delayedError
+}
+
+func (uc *udpclient) Query(q Query) (*Response, error) {
+	return nil, fmt.Errorf("Querying via UDP is not supported")
+}
+
+func (uc *udpclient) Ping(timeout time.Duration) (time.Duration, string, error) {
+	return 0, "", nil
+}