Debug mode

[rwadowski]

I am starting to work on this project and I have question - how to debug the codebase ? - I want to use JetBrains Goland and ideally I want to run the app with the ide in debug mode. I did not find too much info how to run it locally with minimal run. I am not golang expert (I com from the jvm world) so maybe it is not the golang way.

[superrxan]

Hi rwadowski

There is a quick method to play around with eKuiper locally. please refer following steps :

1. Build the binary executable kuiper and kuiperd, where kuiperd is the process engine and kuiper is cli client.
   you can download the source code and just run make, these files will be built and put into the _build/kuiper-*/bin/

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; also set kuiperd to debug mode . Then run the kuiperd

    export MQTT_SOURCE__DEFAULT__SERVERS="[tcp://broker.emqx.io:1883]"
    export KUIPER__BASIC__DEBUG="true"
    #go to the _build/kuiper-*/ and run kuiperd
    ./bin/kuiperd

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.

   # open another shell ,go to the _build/kuiper-*/ and run kuiper cli
   ./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.
   

4. Create a rule by sql, in the same terminal with step3 and type

    ./bin/kuiper query
    kuiper > select * from demo where temperature > 30;
     Query was submit successfully.
   

5. Publish sensor data to topic devices/device_001/messages of server tcp://broker.emqx.io:1883 with any MQTT client tools. You can also use MQTTX . Below sample uses mosquitto_pub.

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

6. 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}]
   

7. you can check the logs in the log directory to debug

Reference:
https://github.com/lf-edge/ekuiper/blob/master/deploy/docker/README.md

[ngjaying]

Thanks @superrxan . I will add some tips about debugging in Goland. The general usage instruction can be found on GoLand help. Specific to eKuiper, you can debug with the same procedure. Just need to find out the entry program:

1. Debug the whole program. Make sure data, plugins/sources, plugins/functions, plugins/sinks, , logs are created in the eKuiper root path. Add your breakpoints. Open cmd/kuiperd/main.go. In the main function, you'll find a green triangle in the ruler, click it and select debug. Then create your stream/rule that would run through your breakpoint, the debugger will pause there.
2. To debug a small portion of code, I recommend to write a unit test and debug it. You can go to any test file and find the same green triangle to run in debug mode. For example, pkg/cast/cast_test.go TestMapConvert_Funcs can run as debug.

[rwadowski]

So the root path is the path of the project ?

[ngjaying]

yes

[rwadowski]

I have deleted KuiperBaseKey env variable and I have something like this conf dir not found, please set KuiperBaseKey program environment variable correctly.

[ngjaying]

make sure you have all the directories listed in line 19 of the Makefile

[rwadowski]

awesome it worked and I was able to catch breakpoint, thanks for help