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1. Pull an eKuiper Docker image from https://hub.docker.com/r/emqxlfedge/kuiperekuiper/tags. It's recommended to use alpine image in this tutorial (refer to eKuiper Docker for the difference of eKuiper Docker image variants).

2. Set eKuiper source to an MQTT server. This sample uses server locating at tcp://broker.emqx.io:1883. broker.emqx.io is a public MQTT test server hosted by EMQ.

   docker run -p 9081:9081 -d --name kuiperekuiper -e MQTT_SOURCE__DEFAULT__SERVERS=[tcp://broker.emqx.io:1883] emqxlfedge/kuiperekuiper:$tag

3. Create a stream - the stream is your stream data schema, similar to table definition in database. Let's say the temperature & humidity data are sent to broker.emqx.io, and those data will be processed in your LOCAL RUN eKuiper docker instance. Below steps will create a stream named demo, and data are sent to devices/device_001/messages topic, while device_001 could be other devices, such as device_002, all of those data will be subscribed and handled by demo stream.

   -- In host
   # docker exec -it kuiperekuiper /bin/sh
   
   -- In docker instance
   # bin/kuiper create stream demo '(temperature float, humidity bigint) WITH (FORMAT="JSON", DATASOURCE="devices/+/messages")'
   Connecting to 127.0.0.1:20498...
   Stream demo is created.
   
   # bin/kuiper query
   Connecting to 127.0.0.1:20498...
   kuiper > select * from demo where temperature > 30;
   Query was submit successfully.
   

4. Publish sensor data to topic devices/device_001/messages of server tcp://broker.emqx.io:1883 with any MQTT client tools. Below sample uses mosquitto_pub.

   # mosquitto_pub -h broker.emqx.io -m '{"temperature": 40, "humidity" : 20}' -t devices/device_001/messages

5. If everything goes well, you can see the message is print on docker bin/kuiper query window. Please try to publish another message with temperature less than 30, and it will be filtered by WHERE condition of the SQL.

   kuiper > select * from demo WHERE temperature > 30;
   [{"temperature": 40, "humidity" : 20}]
   

   If having any problems, please take a look at log/stream.log.

6. To stop the test, just press ctrl + c in bin/kuiper query command console, or input exit and press enter.

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