Documentation

MQTT Notification Settings

This page documents settings for configuring an MQTT service as a target for Bucket Notifications. See Publish Events to MQTT for a tutorial on using these settings.

You can establish or modify settings by defining:

  • an environment variable on the host system prior to starting or restarting the MinIO Server. Refer to your operating system’s documentation for how to define an environment variable.

  • a configuration setting using mc admin config set.

  • a configuration setting using the MinIO Console’s Administrator > Settings pages.

If you define both an environment variable and the similar configuration setting, MinIO uses the environment variable value.

Some settings have only an environment variable or a configuration setting, but not both.

Important

Each configuration setting controls fundamental MinIO behavior and functionality. MinIO strongly recommends testing configuration changes in a lower environment, such as DEV or QA, before applying to production.

Multiple MQTT Targets

You can specify multiple MQTT service endpoints by appending a unique identifier _ID for each set of related MQTT settings to the top level key. For example, the following commands set two distinct MQTT service endpoints as PRIMARY and SECONDARY, respectively:

set MINIO_NOTIFY_MQTT_ENABLE_PRIMARY="on"
set MINIO_NOTIFY_MQTT_BROKER_PRIMARY="tcp://user:password@mqtt-endpoint.example.net:1883"

set MINIO_NOTIFY_MQTT_ENABLE_SECONDARY="on"
set MINIO_NOTIFY_MQTT_BROKER_SECONDARY="tcp://user:password@mqtt-endpoint.example.net:1883"
mc admin config set notify_mqtt:primary \
   broker="tcp://endpoint:port" \
   topic="minio/bucket-name/events/" \
   username="username" \
   password="password" \
   [ARGUMENT="VALUE"] ... \

mc admin config set notify_mqtt:secondary \
   broker="tcp://endpoint:port" \
   topic="minio/bucket-name/events/" \
   username="username" \
   password="password" \
   [ARGUMENT="VALUE"] ... \

With these settings, MINIO_NOTIFY_MQTT_ENABLE_PRIMARY indicates the environment variable is associated to an MQTT service endpoint with an ID of PRIMARY.

Settings

Enable

Required

MINIO_NOTIFY_MQTT_ENABLE

Specify on to enable publishing bucket notifications to an MQTT endpoint.

Defaults to off.

notify_mqtt

The top-level configuration key for defining an MQTT server/broker endpoint for use with MinIO bucket notifications.

Use mc admin config set to set or update an MQTT server/broker endpoint. The following arguments are required for each endpoint:

  • broker

  • topic

  • username Optional if MQTT server/broker does not enforce authentication/authorization

  • password Optional if MQTT server/broker does not enforce authentication/authorization

Specify additional optional arguments as a whitespace (" ")-delimited list.

mc admin config set notify_mqtt \
   broker="tcp://endpoint:port" \
   topic="minio/bucket-name/events/" \
   username="username" \
   password="password" \
   [ARGUMENT="VALUE"] ... \

Broker

Required

MINIO_NOTIFY_MQTT_BROKER
notify_mqtt broker

Specify the MQTT server/broker endpoint. MinIO supports TCP, TLS, or Websocket connections to the server/broker URL. For example:

  • tcp://mqtt.example.net:1883

  • tls://mqtt.example.net:1883

  • ws://mqtt.example.net:1883

Changed in version RELEASE.2023-05-27T05-56-19Z: MinIO checks the health of the specified URL (if it is resolvable and reachable) prior to adding the target. MinIO no longer blocks adding new notification targets if existing targets are offline.

Topic

Required

MINIO_NOTIFY_MQTT_TOPIC
notify_mqtt topic

Specify the name of the MQTT topic to associate with events published by MinIO to the MQTT endpoint.

Username

Required if the MQTT server/broker enforces authentication/authorization

MINIO_NOTIFY_MQTT_USERNAME
notify_mqtt username

Specify the MQTT username MinIO should use to authenticate to the MQTT server/broker.

Password

Required if the MQTT server/broker enforces authentication/authorization

MINIO_NOTIFY_MQTT_PASSWORD
notify_mqtt password

Specify the password for the MQTT username MinIO uses to authenticate to the MQTT server/broker.

Changed in version RELEASE.2023-06-23T20-26-00Z: MinIO redacts this value when returned as part of mc admin config get.

Quality of Service

Optional

MINIO_NOTIFY_MQTT_QOS
notify_mqtt qos

Specify the Quality of Service priority for the published events.

Defaults to 0.

Keep Alive Interval

Optional

MINIO_NOTIFY_MQTT_KEEP_ALIVE_INTERVAL
notify_mqtt keep_alive_interval

Specify the keep-alive interval for the MQTT connections. MinIO supports the following units of time measurement:

  • s - seconds, “60s”

  • m - minutes, “60m”

  • h - hours, “24h”

  • d - days, “7d”

Reconnect Interval

Optional

MINIO_NOTIFY_MQTT_RECONNECT_INTERVAL
notify_mqtt reconnect_interval

Specify the reconnect interval for the MQTT connections. MinIO supports the following units of time measurement:

  • s - seconds, “60s”

  • m - minutes, “60m”

  • h - hours, “24h”

  • d - days, “7d”

Queue Directory

Optional

MINIO_NOTIFY_MQTT_QUEUE_DIR
notify_mqtt queue_dir

Specify the directory path to enable MinIO’s persistent event store for undelivered messages, such as /opt/minio/events.

MinIO stores undelivered events in the specified store while the MQTT server/broker is offline and replays the stored events when connectivity resumes.

Queue Limit

Optional

MINIO_NOTIFY_MQTT_QUEUE_LIMIT
notify_mqtt queue_limit

Specify the maximum limit for undelivered messages. Defaults to 100000.

Comment

Optional

MINIO_NOTIFY_MQTT_COMMENT
notify_mqtt comment

Specify a comment to associate with the MQTT configuration.