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Buckit Object Storage User Guide

Publish Events to MQTT

Buckit supports publishing bucket notification events to MQTT server/broker endpoint.

Add an MQTT Endpoint to a Buckit Deployment

The following procedure adds a new MQTT service endpoint for supporting bucket notifications in a Buckit deployment.

Prerequisites

MQTT 3.1 or 3.1.1 Server/Broker

This procedure assumes an existing MQTT 3.1 or 3.1.1 server/broker to which the Buckit deployment has connectivity. See the mqtt.org software listing for a list of MQTT-compatible server/brokers.

If the MQTT service requires authentication, you must provide an appropriate username and password during the configuration process to grant Buckit access to the service.

Buckit bm Command Line Tool

This procedure uses the bm command line tool for certain actions. See the bm Quickstart for installation instructions.

1) Add the MQTT Endpoint to Buckit

You can configure a new MQTT service endpoint using either environment variables or by setting runtime configuration settings.

Buckit supports specifying the MQTT service endpoint and associated configuration settings using environment variables. The buckit server process applies the specified settings on its next startup.

The following example code sets all environment variables related to configuring an MQTT service endpoint. The minimum required variables are:

   export MINIO_NOTIFY_MQTT_ENABLE_<IDENTIFIER>="on"
   export MINIO_NOTIFY_MQTT_BROKER_<IDENTIFIER>="ENDPOINT"
   export MINIO_NOTIFY_MQTT_TOPIC_<IDENTIFIER>="TOPIC"
   export MINIO_NOTIFY_MQTT_USERNAME_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_PASSWORD_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_QOS_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_KEEP_ALIVE_INTERVAL_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_RECONNECT_INTERVAL_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_QUEUE_DIR_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_QUEUE_LIMIT_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_MQTT_COMMENT_<IDENTIFIER>="<string>"

  • Replace <IDENTIFIER> with a unique descriptive string for the MQTT service endpoint. Use the same <IDENTIFIER> value for all environment variables related to the new MQTT service endpoint. The following examples assume an identifier of PRIMARY.

    If the specified <IDENTIFIER> matches an existing MQTT service endpoint on the Buckit deployment, the new settings override any existing settings for that endpoint. Use bm admin config get notify_mqtt to review the currently configured MQTT endpoints on the Buckit deployment.

  • Replace <ENDPOINT> with the URL of the MQTT service endpoint. For example:

    tcp://hostname:port

  • Replace TOPIC with the MQTT topic to which Buckit associates events published to the server/broker.

See MQTT Service for Bucket Notifications for complete documentation on each environment variable.

Buckit supports adding or updating MQTT endpoints on a running buckit server process using the bm admin config set command and the notify_mqtt configuration key. You must restart the buckit server process to apply any new or updated configuration settings.

The following example code sets all settings related to configuring an MQTT service endpoint. The following configuration settings are the minimum required for an MQTT server/broker endpoint:

  • broker

  • topic

  • username Required if the MQTT server/broker enforces authentication/authorization

  • password Required if the MQTT server/broker enforces authentication/authorization

bm admin config set ALIAS/ notify_mqtt:IDENTIFIER \
   broker="ENDPOINT" \
   topic="TOPIC" \
   username="username" \
   password="password" \
   qos="<integer>" \
   keep_alive_interval="60s|m|h|d"
   reconnect_interval="60s|m|h|d"
   queue_dir="<string>" \
   queue_limit="<string>" \
   comment="<string>"

  • Replace IDENTIFIER with a unique descriptive string for the MQTT service endpoint. The following examples in this procedure assume an identifier of PRIMARY.

    If the specified IDENTIFIER matches an existing MQTT service endpoint on the Buckit deployment, the new settings override any existing settings for that endpoint. Use bm admin config get notify_mqtt to review the currently configured MQTT endpoints on the Buckit deployment.

  • Replace ENDPOINT with the URL of the MQTT service endpoint. For example:

    tcp://hostname:port

  • Replace TOPIC with the MQTT topic to which Buckit associates events published to the server/broker.

See MQTT Bucket Notification Configuration Settings for complete documentation on each setting.

1) Restart the Buckit Deployment

You must restart the Buckit deployment to apply the configuration changes. Use the bm admin service restart command to restart the deployment.

bm admin service restart ALIAS

Replace ALIAS with the alias of the deployment to restart.

The buckit server process prints a line on startup for each configured MQTT target similar to the following:

SQS ARNs: arn:minio:sqs::primary:mqtt

You must specify the ARN resource when configuring bucket notifications with the associated MQTT deployment as a target.

Identifying the ARN for your bucket notifications

You defined the <IDENTIFIER> to assign to the target ARN for your bucket notifications when creating the endpoint previously. The steps below return the ARNs configured on the deployment. Identify the ARN created previously by looking for the <IDENTIFIER> you specified.

Review the JSON output

  1. Copy and run the following command, replacing ALIAS with the alias of the deployment.

    bm admin info --json ALIAS

  2. In the JSON output, look for the key info.sqsARN.

    The ARN you need is the value of that key that matches the <IDENTIFIER> you specified.

    For example, arn:minio:sqs::primary:mqtt.

Use jq to parse the JSON for the value

  1. Install jq

  2. Copy and run the following command, replacing ALIAS with the alias of the deployment.

    bm admin info --json ALIAS | jq  .info.sqsARN

    This returns the ARN to use for notifications, such as arn:minio:sqs::primary:mqtt

1) Configure Bucket Notifications using the MQTT Endpoint as a Target

Use the bm event add command to add a new bucket notification event with the configured MQTT service as a target:

bm event add ALIAS/BUCKET arn:minio:sqs::primary:mqtt \
  --event EVENTS

  • Replace ALIAS with the alias of a Buckit deployment.

  • Replace BUCKET with the name of the bucket in which to configure the event.

  • Replace EVENTS with a comma-separated list of events for which Buckit triggers notifications.

Use bm event ls to view all configured bucket events for a given notification target:

bm event ls ALIAS/BUCKET arn:minio:sqs::primary:MQTT

4) Validate the Configured Events

Perform an action on the bucket for which you configured the new event and check the MQTT service for the notification data. The action required depends on which events were specified when configuring the bucket notification.

For example, if the bucket notification configuration includes the s3:ObjectCreated:Put event, you can use the bm cp command to create a new object in the bucket and trigger a notification.

bm cp ~/data/new-object.txt ALIAS/BUCKET

Update an MQTT Endpoint in a Buckit Deployment

The following procedure updates an existing MQTT service endpoint for supporting bucket notifications in a Buckit deployment.

Prerequisites

MQTT 3.1 or 3.1.1 Server/Broker Endpoint

This procedure assumes an existing MQTT 3.1 or 3.1.1 server/broker to which the Buckit deployment has connectivity. See the mqtt.org software listing for a list of MQTT-compatible server/brokers.

If the MQTT service requires authentication, you must provide an appropriate username and password during the configuration process to grant Buckit access to the service.

Buckit bm Command Line Tool

This procedure uses the bm command line tool for certain actions. See the bm Quickstart for installation instructions.

1) List Configured MQTT Endpoints In The Deployment

Use the bm admin config get command to list the currently configured MQTT service endpoints in the deployment:

bm admin config get ALIAS/ notify_mqtt

Replace ALIAS with the alias of the Buckit deployment.

The command output resembles the following:

notify_mqtt:primary  broker="tcp://mqtt-primary.example.net:port" password="" queue_dir="" queue_limit="0" reconnect_interval="0s"  keep_alive_interval="0s" qos="0" topic="" username=""
notify_mqtt:secondary  broker="tcp://mqtt-primary.example.net:port" password="" queue_dir="" queue_limit="0" reconnect_interval="0s"  keep_alive_interval="0s" qos="0" topic="" username=""

The notify_mqtt key is the top-level configuration key for an MQTT Notification Settings. The broker key specifies the MQTT server/broker endpoint for the given notify_mqtt key. The notify_mqtt:<IDENTIFIER> suffix describes the unique identifier for that MQTT service endpoint.

Note the identifier for the MQTT service endpoint you want to update for the next step.

2) Update the MQTT Endpoint

Use the bm admin config set command to set the new configuration for the MQTT service endpoint:

bm admin config set ALIAS/ notify_mqtt:<IDENTIFIER> \
   url="MQTT://user:password@hostname:port" \
   exchange="<string>" \
   exchange_type="<string>" \
   routing_key="<string>" \
   mandatory="<string>" \
   durable="<string>" \
   no_wait="<string>" \
   internal="<string>" \
   auto_deleted="<string>" \
   delivery_mode="<string>" \
   queue_dir="<string>" \
   queue_limit="<string>" \
   comment="<string>"

The following configuration settings are the minimum required for an MQTT server/broker endpoint:

  • broker

  • topic

  • username Required if the MQTT server/broker enforces authentication/authorization

  • password Required if the MQTT server/broker enforces authentication/authorization

All other configuration settings are optional. See MQTT Notification Settings for a complete list of MQTT configuration settings.

3) Restart the Buckit Deployment

You must restart the Buckit deployment to apply the configuration changes. Use the bm admin service restart command to restart the deployment.

bm admin service restart ALIAS

Replace ALIAS with the alias of the deployment to restart.

The buckit server process prints a line on startup for each configured MQTT target similar to the following:

SQS ARNs: arn:minio:sqs::primary:mqtt

3) Validate the Changes

Perform an action on a bucket which has an event configuration using the updated MQTT service endpoint and check the MQTT service for the notification data. The action required depends on which events were specified when configuring the bucket notification.

For example, if the bucket notification configuration includes the s3:ObjectCreated:Put event, you can use the bm cp command to create a new object in the bucket and trigger a notification.

bm cp ~/data/new-object.txt ALIAS/BUCKET
Buckit documentation adapted from MinIO Open Source documentation. Licensed under the Creative Commons Attribution 4.0 International License. Creative Commons License