package graphite import ( "crypto/tls" "errors" "io" "log" "math/rand" "net" "time" "github.com/influxdata/telegraf" tlsint "github.com/influxdata/telegraf/internal/tls" "github.com/influxdata/telegraf/plugins/outputs" "github.com/influxdata/telegraf/plugins/serializers" ) type Graphite struct { GraphiteTagSupport bool // URL is only for backwards compatibility Servers []string Prefix string Template string Timeout int conns []net.Conn tlsint.ClientConfig } var sampleConfig = ` ## TCP endpoint for your graphite instance. ## If multiple endpoints are configured, output will be load balanced. ## Only one of the endpoints will be written to with each iteration. servers = ["localhost:2003"] ## Prefix metrics name prefix = "" ## Graphite output template ## see https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_OUTPUT.md template = "host.tags.measurement.field" ## Enable Graphite tags support # graphite_tag_support = false ## timeout in seconds for the write connection to graphite timeout = 2 ## Optional TLS Config # tls_ca = "/etc/telegraf/ca.pem" # tls_cert = "/etc/telegraf/cert.pem" # tls_key = "/etc/telegraf/key.pem" ## Use TLS but skip chain & host verification # insecure_skip_verify = false ` func (g *Graphite) Connect() error { // Set default values if g.Timeout <= 0 { g.Timeout = 2 } if len(g.Servers) == 0 { g.Servers = append(g.Servers, "localhost:2003") } // Set tls config tlsConfig, err := g.ClientConfig.TLSConfig() if err != nil { return err } // Get Connections var conns []net.Conn for _, server := range g.Servers { // Dialer with timeout d := net.Dialer{Timeout: time.Duration(g.Timeout) * time.Second} // Get secure connection if tls config is set var conn net.Conn if tlsConfig != nil { conn, err = tls.DialWithDialer(&d, "tcp", server, tlsConfig) } else { conn, err = d.Dial("tcp", server) } if err == nil { conns = append(conns, conn) } } g.conns = conns return nil } func (g *Graphite) Close() error { // Closing all connections for _, conn := range g.conns { conn.Close() } return nil } func (g *Graphite) SampleConfig() string { return sampleConfig } func (g *Graphite) Description() string { return "Configuration for Graphite server to send metrics to" } // We need check eof as we can write to nothing without noticing anything is wrong // the connection stays in a close_wait // We can detect that by finding an eof // if not for this, we can happily write and flush without getting errors (in Go) but getting RST tcp packets back (!) // props to Tv via the authors of carbon-relay-ng` for this trick. func checkEOF(conn net.Conn) { b := make([]byte, 1024) conn.SetReadDeadline(time.Now().Add(10 * time.Millisecond)) num, err := conn.Read(b) if err == io.EOF { log.Printf("E! Conn %s is closed. closing conn explicitly", conn) conn.Close() return } // just in case i misunderstand something or the remote behaves badly if num != 0 { log.Printf("I! conn %s .conn.Read data? did not expect that. data: %s\n", conn, b[:num]) } // Log non-timeout errors or close. if e, ok := err.(net.Error); !(ok && e.Timeout()) { log.Printf("E! conn %s checkEOF .conn.Read returned err != EOF, which is unexpected. closing conn. error: %s\n", conn, err) conn.Close() } } // Choose a random server in the cluster to write to until a successful write // occurs, logging each unsuccessful. If all servers fail, return error. func (g *Graphite) Write(metrics []telegraf.Metric) error { // Prepare data var batch []byte s, err := serializers.NewGraphiteSerializer(g.Prefix, g.Template, g.GraphiteTagSupport) if err != nil { return err } for _, metric := range metrics { buf, err := s.Serialize(metric) if err != nil { log.Printf("E! Error serializing some metrics to graphite: %s", err.Error()) } batch = append(batch, buf...) } err = g.send(batch) // try to reconnect and retry to send if err != nil { log.Println("E! Graphite: Reconnecting and retrying: ") g.Connect() err = g.send(batch) } return err } func (g *Graphite) send(batch []byte) error { // This will get set to nil if a successful write occurs err := errors.New("Could not write to any Graphite server in cluster\n") // Send data to a random server p := rand.Perm(len(g.conns)) for _, n := range p { if g.Timeout > 0 { g.conns[n].SetWriteDeadline(time.Now().Add(time.Duration(g.Timeout) * time.Second)) } checkEOF(g.conns[n]) if _, e := g.conns[n].Write(batch); e != nil { // Error log.Println("E! Graphite Error: " + e.Error()) // Close explicitely g.conns[n].Close() // Let's try the next one } else { // Success err = nil break } } return err } func init() { outputs.Add("graphite", func() telegraf.Output { return &Graphite{} }) }