package mqtt_consumer import ( "context" "errors" "fmt" "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 `toml:"servers"` Topics []string `toml:"topics"` TopicTag *string `toml:"topic_tag"` Username string `toml:"username"` Password string `toml:"password"` 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 Log telegraf.Logger clientFactory ClientFactory client Client opts *mqtt.ClientOptions acc telegraf.TrackingAccumulator state ConnectionState sem semaphore messages map[telegraf.TrackingID]bool topicTag string 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/#", ] ## The message topic will be stored in a tag specified by this value. If set ## to the empty string no topic tag will be created. # topic_tag = "topic" ## 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 identify ## 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) } m.topicTag = "topic" if m.TopicTag != nil { m.topicTag = *m.TopicTag } 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.sem = make(semaphore, 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 persisted 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 } m.Log.Infof("Connected %v", m.Servers) m.state = Connected m.messages = make(map[telegraf.TrackingID]bool) // Persistent 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() { m.Log.Debugf("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)) m.Log.Debugf("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(): <-m.sem _, ok := m.messages[track.ID()] if !ok { // Added by a previous connection continue } // 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 } if m.topicTag != "" { topic := msg.Topic() for _, metric := range metrics { metric.AddTag(m.topicTag, topic) } } id := acc.AddTrackingMetricGroup(metrics) m.messages[id] = true return nil } func (m *MQTTConsumer) Stop() { if m.state == Connected { m.Log.Debugf("Disconnecting %v", m.Servers) m.client.Disconnect(200) m.Log.Debugf("Disconnected %v", m.Servers) m.state = Disconnected } m.cancel() } func (m *MQTTConsumer) Gather(acc telegraf.Accumulator) error { if m.state == Disconnected { m.state = Connecting m.Log.Debugf("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 informations") } for _, server := range m.Servers { // Preserve support for host:port style servers; deprecated in Telegraf 1.4.4 if !strings.Contains(server, "://") { m.Log.Warnf("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) }) }) }