From 0084138bc6b1789b63c731abefdbfb3507620868 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pawe=C5=82=20Kraszewski?= Date: Tue, 12 Feb 2019 02:22:31 +0100 Subject: [PATCH] Add option to set retain flag on messages in mqtt output (#4892) --- plugins/outputs/mqtt/README.md | 7 ++++++- plugins/outputs/mqtt/mqtt.go | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/plugins/outputs/mqtt/README.md b/plugins/outputs/mqtt/README.md index 14c166f9e..697418218 100644 --- a/plugins/outputs/mqtt/README.md +++ b/plugins/outputs/mqtt/README.md @@ -32,10 +32,14 @@ This plugin writes to a [MQTT Broker](http://http://mqtt.org/) acting as a mqtt # 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 = flase ## Data format to output. # data_format = "influx" @@ -56,4 +60,5 @@ This plugin writes to a [MQTT Broker](http://http://mqtt.org/) acting as a mqtt * `tls_cert`: TLS CERT * `tls_key`: TLS key * `insecure_skip_verify`: Use TLS but skip chain & host verification (default: false) +* `retain`: Set `retain` flag when publishing, instructing server to cache metric until someone reads it (default: false) * `data_format`: [About Telegraf data formats](https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_OUTPUT.md) diff --git a/plugins/outputs/mqtt/mqtt.go b/plugins/outputs/mqtt/mqtt.go index 18e22daa6..55d9532db 100644 --- a/plugins/outputs/mqtt/mqtt.go +++ b/plugins/outputs/mqtt/mqtt.go @@ -49,6 +49,10 @@ var sampleConfig = ` ## 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 = flase ## Data format to output. ## Each data format has its own unique set of configuration options, read @@ -68,6 +72,7 @@ type MQTT struct { ClientID string `toml:"client_id"` tls.ClientConfig BatchMessage bool `toml:"batch"` + Retain bool client paho.Client opts *paho.ClientOptions @@ -174,7 +179,7 @@ func (m *MQTT) Write(metrics []telegraf.Metric) error { } func (m *MQTT) publish(topic string, body []byte) error { - token := m.client.Publish(topic, byte(m.QoS), false, body) + token := m.client.Publish(topic, byte(m.QoS), m.Retain, body) token.WaitTimeout(m.Timeout.Duration) if token.Error() != nil { return token.Error()