telegraf/plugins/inputs/mqtt_consumer/mqtt_consumer.go

371 lines
9.5 KiB
Go

package mqtt_consumer
import (
"context"
"errors"
"fmt"
"log"
"strings"
"time"
"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/inputs"
"github.com/influxdata/telegraf/plugins/parsers"
)
var (
// 30 Seconds is the default used by paho.mqtt.golang
defaultConnectionTimeout = internal.Duration{Duration: 30 * time.Second}
defaultMaxUndeliveredMessages = 1000
)
type ConnectionState int
type empty struct{}
type semaphore chan empty
const (
Disconnected ConnectionState = iota
Connecting
Connected
)
type Client interface {
Connect() mqtt.Token
SubscribeMultiple(filters map[string]byte, callback mqtt.MessageHandler) mqtt.Token
AddRoute(topic string, callback mqtt.MessageHandler)
Disconnect(quiesce uint)
}
type ClientFactory func(o *mqtt.ClientOptions) Client
type MQTTConsumer struct {
Servers []string
Topics []string
Username string
Password string
QoS int `toml:"qos"`
ConnectionTimeout internal.Duration `toml:"connection_timeout"`
MaxUndeliveredMessages int `toml:"max_undelivered_messages"`
parser parsers.Parser
// Legacy metric buffer support; deprecated in v0.10.3
MetricBuffer int
PersistentSession bool
ClientID string `toml:"client_id"`
tls.ClientConfig
clientFactory ClientFactory
client Client
opts *mqtt.ClientOptions
acc telegraf.TrackingAccumulator
state ConnectionState
sem semaphore
messages map[telegraf.TrackingID]bool
ctx context.Context
cancel context.CancelFunc
}
var sampleConfig = `
## MQTT broker URLs to be used. The format should be scheme://host:port,
## schema can be tcp, ssl, or ws.
servers = ["tcp://127.0.0.1:1883"]
## Topics that will be subscribed to.
topics = [
"telegraf/host01/cpu",
"telegraf/+/mem",
"sensors/#",
]
## QoS policy for messages
## 0 = at most once
## 1 = at least once
## 2 = exactly once
##
## When using a QoS of 1 or 2, you should enable persistent_session to allow
## resuming unacknowledged messages.
# qos = 0
## Connection timeout for initial connection in seconds
# connection_timeout = "30s"
## Maximum messages to read from the broker that have not been written by an
## output. For best throughput set based on the number of metrics within
## each message and the size of the output's metric_batch_size.
##
## For example, if each message from the queue contains 10 metrics and the
## output metric_batch_size is 1000, setting this to 100 will ensure that a
## full batch is collected and the write is triggered immediately without
## waiting until the next flush_interval.
# max_undelivered_messages = 1000
## Persistent session disables clearing of the client session on connection.
## In order for this option to work you must also set client_id to identity
## the client. To receive messages that arrived while the client is offline,
## also set the qos option to 1 or 2 and don't forget to also set the QoS when
## publishing.
# persistent_session = false
## If unset, a random client ID will be generated.
# client_id = ""
## Username and password to connect MQTT server.
# username = "telegraf"
# password = "metricsmetricsmetricsmetrics"
## 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
## Data format to consume.
## 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_INPUT.md
data_format = "influx"
`
func (m *MQTTConsumer) SampleConfig() string {
return sampleConfig
}
func (m *MQTTConsumer) Description() string {
return "Read metrics from MQTT topic(s)"
}
func (m *MQTTConsumer) SetParser(parser parsers.Parser) {
m.parser = parser
}
func (m *MQTTConsumer) Init() error {
m.state = Disconnected
if m.PersistentSession && m.ClientID == "" {
return errors.New("persistent_session requires client_id")
}
if m.QoS > 2 || m.QoS < 0 {
return fmt.Errorf("qos value must be 0, 1, or 2: %d", m.QoS)
}
if m.ConnectionTimeout.Duration < 1*time.Second {
return fmt.Errorf("connection_timeout must be greater than 1s: %s", m.ConnectionTimeout.Duration)
}
opts, err := m.createOpts()
if err != nil {
return err
}
m.opts = opts
return nil
}
func (m *MQTTConsumer) Start(acc telegraf.Accumulator) error {
m.state = Disconnected
m.acc = acc.WithTracking(m.MaxUndeliveredMessages)
m.ctx, m.cancel = context.WithCancel(context.Background())
m.client = m.clientFactory(m.opts)
// AddRoute sets up the function for handling messages. These need to be
// added in case we find a persistent session containing subscriptions so we
// know where to dispatch presisted and new messages to. In the alternate
// case that we need to create the subscriptions these will be replaced.
for _, topic := range m.Topics {
m.client.AddRoute(topic, m.recvMessage)
}
m.state = Connecting
m.connect()
return nil
}
func (m *MQTTConsumer) connect() error {
token := m.client.Connect()
if token.Wait() && token.Error() != nil {
err := token.Error()
m.state = Disconnected
return err
}
log.Printf("I! [inputs.mqtt_consumer] Connected %v", m.Servers)
m.state = Connected
m.sem = make(semaphore, m.MaxUndeliveredMessages)
m.messages = make(map[telegraf.TrackingID]bool)
// Presistent sessions should skip subscription if a session is present, as
// the subscriptions are stored by the server.
type sessionPresent interface {
SessionPresent() bool
}
if t, ok := token.(sessionPresent); ok && t.SessionPresent() {
log.Printf("D! [inputs.mqtt_consumer] Session found %v", m.Servers)
return nil
}
topics := make(map[string]byte)
for _, topic := range m.Topics {
topics[topic] = byte(m.QoS)
}
subscribeToken := m.client.SubscribeMultiple(topics, m.recvMessage)
subscribeToken.Wait()
if subscribeToken.Error() != nil {
m.acc.AddError(fmt.Errorf("subscription error: topics: %s: %v",
strings.Join(m.Topics[:], ","), subscribeToken.Error()))
}
return nil
}
func (m *MQTTConsumer) onConnectionLost(c mqtt.Client, err error) {
m.acc.AddError(fmt.Errorf("connection lost: %v", err))
log.Printf("D! [inputs.mqtt_consumer] Disconnected %v", m.Servers)
m.state = Disconnected
return
}
func (m *MQTTConsumer) recvMessage(c mqtt.Client, msg mqtt.Message) {
for {
select {
case track := <-m.acc.Delivered():
_, ok := m.messages[track.ID()]
if !ok {
// Added by a previous connection
continue
}
<-m.sem
// No ack, MQTT does not support durable handling
delete(m.messages, track.ID())
case m.sem <- empty{}:
err := m.onMessage(m.acc, msg)
if err != nil {
m.acc.AddError(err)
<-m.sem
}
return
}
}
}
func (m *MQTTConsumer) onMessage(acc telegraf.TrackingAccumulator, msg mqtt.Message) error {
metrics, err := m.parser.Parse(msg.Payload())
if err != nil {
return err
}
topic := msg.Topic()
for _, metric := range metrics {
metric.AddTag("topic", topic)
}
id := acc.AddTrackingMetricGroup(metrics)
m.messages[id] = true
return nil
}
func (m *MQTTConsumer) Stop() {
if m.state == Connected {
log.Printf("D! [inputs.mqtt_consumer] Disconnecting %v", m.Servers)
m.client.Disconnect(200)
log.Printf("D! [inputs.mqtt_consumer] Disconnected %v", m.Servers)
m.state = Disconnected
}
m.cancel()
}
func (m *MQTTConsumer) Gather(acc telegraf.Accumulator) error {
if m.state == Disconnected {
m.state = Connecting
log.Printf("D! [inputs.mqtt_consumer] Connecting %v", m.Servers)
m.connect()
}
return nil
}
func (m *MQTTConsumer) createOpts() (*mqtt.ClientOptions, error) {
opts := mqtt.NewClientOptions()
opts.ConnectTimeout = m.ConnectionTimeout.Duration
if m.ClientID == "" {
opts.SetClientID("Telegraf-Consumer-" + internal.RandomString(5))
} else {
opts.SetClientID(m.ClientID)
}
tlsCfg, err := m.ClientConfig.TLSConfig()
if err != nil {
return nil, err
}
if tlsCfg != nil {
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 _, server := range m.Servers {
// Preserve support for host:port style servers; deprecated in Telegraf 1.4.4
if !strings.Contains(server, "://") {
log.Printf("W! [inputs.mqtt_consumer] Server %q should be updated to use `scheme://host:port` format", server)
if tlsCfg == nil {
server = "tcp://" + server
} else {
server = "ssl://" + server
}
}
opts.AddBroker(server)
}
opts.SetAutoReconnect(false)
opts.SetKeepAlive(time.Second * 60)
opts.SetCleanSession(!m.PersistentSession)
opts.SetConnectionLostHandler(m.onConnectionLost)
return opts, nil
}
func New(factory ClientFactory) *MQTTConsumer {
return &MQTTConsumer{
Servers: []string{"tcp://127.0.0.1:1883"},
ConnectionTimeout: defaultConnectionTimeout,
MaxUndeliveredMessages: defaultMaxUndeliveredMessages,
clientFactory: factory,
state: Disconnected,
}
}
func init() {
inputs.Add("mqtt_consumer", func() telegraf.Input {
return New(func(o *mqtt.ClientOptions) Client {
return mqtt.NewClient(o)
})
})
}