isabella232 / mqtt

MQTT Broker ingestion.

MQTT Streaming Source

The MQTT Streaming Source allows you to subscribe to an MQTT broker in a streaming context. You specify the topic to subscribe to as an MQTT client.

Usage Notes

The MQTT Streaming Source will listen to an MQTT broker and subscribe to a given topic. To do this, you need to supply the host and, optionally, the port of the MQTT broker. If the MQTT protocol is TCP, the default port will be 1883. If the MQTT protocol is SSL, the default port is 8889.

When specifying the MQTT Topic, the wildcards '+' and '#' are permitted. The '+' wildcard indicates we are selecting all topics on that level of hierarchy. The '#' wildcard indicates that we are selecting all topics from that level of hierarchy and children of those topics. This also means that if we choose to use it, '#' must be the last character of a topic subscription.

For example, if we have the topic "a/b/c/d", these will match:

• a/b/c/d
• a/+/c/d
• +/+/+/+
• a/b/c/+
• #
• a/#
• a/b/c/#
• +/b/#

While these will not match:

• a/b/c
• +/+/+
• /#

Additionally, the zero-length topic, "", is permitted:

• "a//b" will be matched by "a/+/b"
• "/a/b" will be matched by "+/a/b" and "/#"

Plugin Configuration

Configuration	Required	Default	Description
Broker URL	Y	N/A	Specifies the MQTT broker to listen to. Must be specified in the form of 'tcp://[:]' or 'ssl://[:]'. If the port is not specified, it will default to 1883 for TCP and 8889 for SSL.
MQTT Topic	Y	N/A	Specifies the MQTT topic to subscribe to. Wildcards '+' and '#' are acceptable and used as described above.

Build

To build this plugin:

mvn clean package

The build will create a .jar and .json file under the target directory. These files can be used to deploy your plugin.

Deployment

You can deploy your plugin using the CDAP CLI:

> load artifact <target/mqtt-<version>.jar config-file <target/mqtt-<version>.json>

For example, if your artifact is named 'mqtt-1.0.0':

> load artifact target/mqtt-1.0.0.jar config-file target/mqtt-1.0.0.json

Mailing Lists

CDAP User Group and Development Discussions:

• [email protected] <https://groups.google.com/d/forum/cdap-user>

The cdap-user mailing list is primarily for users using the product to develop applications or building plugins for appplications. You can expect questions from users, release announcements, and any other discussions that we think will be helpful to the users.

Slack Channel

CDAP Slack Channel: http://cdap-users.herokuapp.com/

License and Trademarks

Copyright © 2017 Cask Data, Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Cask is a trademark of Cask Data, Inc. All rights reserved.

Apache, Apache HBase, and HBase are trademarks of The Apache Software Foundation. Used with permission. No endorsement by The Apache Software Foundation is implied by the use of these marks.