telegraf/plugins/outputs/mqtt/mqtt.go

241 lines
5.1 KiB
Go

package mqtt
import (
"fmt"
"strings"
"sync"
"time"
paho "github.com/eclipse/paho.mqtt.golang"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/internal/tls"
"github.com/influxdata/telegraf/plugins/outputs"
"github.com/influxdata/telegraf/plugins/serializers"
)
var sampleConfig = `
servers = ["localhost:1883"] # required.
## MQTT outputs send metrics to this topic format
## "<topic_prefix>/<hostname>/<pluginname>/"
## ex: prefix/web01.example.com/mem
topic_prefix = "telegraf"
## QoS policy for messages
## 0 = at most once
## 1 = at least once
## 2 = exactly once
# qos = 2
## username and password to connect MQTT server.
# username = "telegraf"
# password = "metricsmetricsmetricsmetrics"
## client ID, if not set a random ID is generated
# client_id = ""
## Timeout for write operations. default: 5s
# timeout = "5s"
## 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
## When true, metrics will be sent in one MQTT message per flush. Otherwise,
## metrics are written one metric per MQTT message.
# batch = false
## When true, metric will have RETAIN flag set, making broker cache entries until someone
## actually reads it
# retain = false
## Data format to output.
## Each data format has its 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"
`
type MQTT struct {
Servers []string `toml:"servers"`
Username string
Password string
Database string
Timeout internal.Duration
TopicPrefix string
QoS int `toml:"qos"`
ClientID string `toml:"client_id"`
tls.ClientConfig
BatchMessage bool `toml:"batch"`
Retain bool `toml:"retain"`
client paho.Client
opts *paho.ClientOptions
serializer serializers.Serializer
sync.Mutex
}
func (m *MQTT) Connect() error {
var err error
m.Lock()
defer m.Unlock()
if m.QoS > 2 || m.QoS < 0 {
return fmt.Errorf("MQTT Output, invalid QoS value: %d", m.QoS)
}
m.opts, err = m.createOpts()
if err != nil {
return err
}
m.client = paho.NewClient(m.opts)
if token := m.client.Connect(); token.Wait() && token.Error() != nil {
return token.Error()
}
return nil
}
func (m *MQTT) SetSerializer(serializer serializers.Serializer) {
m.serializer = serializer
}
func (m *MQTT) Close() error {
if m.client.IsConnected() {
m.client.Disconnect(20)
}
return nil
}
func (m *MQTT) SampleConfig() string {
return sampleConfig
}
func (m *MQTT) Description() string {
return "Configuration for MQTT server to send metrics to"
}
func (m *MQTT) Write(metrics []telegraf.Metric) error {
m.Lock()
defer m.Unlock()
if len(metrics) == 0 {
return nil
}
hostname, ok := metrics[0].Tags()["host"]
if !ok {
hostname = ""
}
metricsmap := make(map[string][]telegraf.Metric)
for _, metric := range metrics {
var t []string
if m.TopicPrefix != "" {
t = append(t, m.TopicPrefix)
}
if hostname != "" {
t = append(t, hostname)
}
t = append(t, metric.Name())
topic := strings.Join(t, "/")
if m.BatchMessage {
metricsmap[topic] = append(metricsmap[topic], metric)
} else {
buf, err := m.serializer.Serialize(metric)
if err != nil {
return err
}
err = m.publish(topic, buf)
if err != nil {
return fmt.Errorf("Could not write to MQTT server, %s", err)
}
}
}
for key := range metricsmap {
buf, err := m.serializer.SerializeBatch(metricsmap[key])
if err != nil {
return err
}
publisherr := m.publish(key, buf)
if publisherr != nil {
return fmt.Errorf("Could not write to MQTT server, %s", publisherr)
}
}
return nil
}
func (m *MQTT) publish(topic string, body []byte) error {
token := m.client.Publish(topic, byte(m.QoS), m.Retain, body)
token.WaitTimeout(m.Timeout.Duration)
if token.Error() != nil {
return token.Error()
}
return nil
}
func (m *MQTT) createOpts() (*paho.ClientOptions, error) {
opts := paho.NewClientOptions()
opts.KeepAlive = 0
if m.Timeout.Duration < time.Second {
m.Timeout.Duration = 5 * time.Second
}
opts.WriteTimeout = m.Timeout.Duration
if m.ClientID != "" {
opts.SetClientID(m.ClientID)
} else {
opts.SetClientID("Telegraf-Output-" + internal.RandomString(5))
}
tlsCfg, err := m.ClientConfig.TLSConfig()
if err != nil {
return nil, err
}
scheme := "tcp"
if tlsCfg != nil {
scheme = "ssl"
opts.SetTLSConfig(tlsCfg)
}
user := m.Username
if user != "" {
opts.SetUsername(user)
}
password := m.Password
if password != "" {
opts.SetPassword(password)
}
if len(m.Servers) == 0 {
return opts, fmt.Errorf("could not get host infomations")
}
for _, host := range m.Servers {
server := fmt.Sprintf("%s://%s", scheme, host)
opts.AddBroker(server)
}
opts.SetAutoReconnect(true)
return opts, nil
}
func init() {
outputs.Add("mqtt", func() telegraf.Output {
return &MQTT{}
})
}