telegraf/plugins/outputs/nats/nats.go

140 lines
3.0 KiB
Go

package nats
import (
"crypto/tls"
"crypto/x509"
"fmt"
"io/ioutil"
nats_client "github.com/nats-io/nats"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/outputs"
"github.com/influxdata/telegraf/plugins/serializers"
)
type NATS struct {
// Servers is the NATS server pool to connect to
Servers []string
// Credentials
Username string
Password string
// NATS subject to publish metrics to
Subject string
// Path to CA file
CAFile string `toml:"tls_ca"`
// Skip SSL verification
InsecureSkipVerify bool
conn *nats_client.Conn
serializer serializers.Serializer
}
var sampleConfig = `
## URLs of NATS servers
servers = ["nats://localhost:4222"]
## Optional credentials
# username = ""
# password = ""
## NATS subject for producer messages
subject = "telegraf"
## Optional TLS Config
## CA certificate used to self-sign NATS server(s) TLS certificate(s)
# tls_ca = "/etc/telegraf/ca.pem"
## Use TLS but skip chain & host verification
# insecure_skip_verify = false
## Data format to output.
## Each data format has it's own unique set of configuration options, read
## more about them here:
## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_OUTPUT.md
data_format = "influx"
`
func (n *NATS) SetSerializer(serializer serializers.Serializer) {
n.serializer = serializer
}
func (n *NATS) Connect() error {
// set NATS connection options
opts := nats_client.DefaultOptions
opts.Servers = n.Servers
if n.Username != "" {
opts.User = n.Username
opts.Password = n.Password
}
// is TLS enabled?
var tlsConfig tls.Config
tlsConfig.InsecureSkipVerify = n.InsecureSkipVerify
if n.CAFile != "" {
rootPEM, err := ioutil.ReadFile(n.CAFile)
if err != nil || rootPEM == nil {
return fmt.Errorf("FAILED to connect to NATS (can't read root certificate): %s", err)
}
pool := x509.NewCertPool()
ok := pool.AppendCertsFromPEM([]byte(rootPEM))
if !ok {
return fmt.Errorf("FAILED to connect to NATS (can't parse root certificate): %s", err)
}
tlsConfig.RootCAs = pool
// set NATS connection TLS options
opts.Secure = true
opts.TLSConfig = &tlsConfig
}
// try and connect
var err error
n.conn, err = opts.Connect()
return err
}
func (n *NATS) Close() error {
n.conn.Close()
return nil
}
func (n *NATS) SampleConfig() string {
return sampleConfig
}
func (n *NATS) Description() string {
return "Send telegraf measurements to NATS"
}
func (n *NATS) Write(metrics []telegraf.Metric) error {
if len(metrics) == 0 {
return nil
}
for _, metric := range metrics {
values, err := n.serializer.Serialize(metric)
if err != nil {
return err
}
var pubErr error
for _, value := range values {
err = n.conn.Publish(n.Subject, []byte(value))
if err != nil {
pubErr = err
}
}
if pubErr != nil {
return fmt.Errorf("FAILED to send NATS message: %s", err)
}
}
return nil
}
func init() {
outputs.Add("nats", func() telegraf.Output {
return &NATS{}
})
}