This is a simple, single threaded Python script that produces JSONs into a Kafka topic. Since in StateFun world, we also require keys (they are used for the initial routing) a JSON path string needs to be provided.
(taken directly from main.py)
APP_PATH = Arg(key="APP_PATH", default="/opt/statefun/example.json", type=str) APP_KAFKA_HOST = Arg(key="APP_KAFKA_HOST", default="kafka-broker:9092", type=str) APP_KAFKA_TOPIC = Arg(key="APP_KAFKA_TOPIC", default="input", type=str) APP_DELAY_SECONDS = Arg(key="APP_DELAY_SECONDS", default="1", type=int) APP_LOOP = Arg(key="APP_LOOP", default="true", type=lambda s: s.lower() == "true") APP_JSON_PATH = Arg(key="APP_JSON_PATH", default="name", type=parse)
Imagine we have the following file at /opt/statefun/example.json
> cat /opt/statefun/example.json
{"name" : "Gorge", "last" : "Costanza"}
{"name" : "Bob", "last" : "Mop"}
Then we need to set:
export APP_PATH=/opt/statefun/example.json export APP_JSON_PATH='name' # note there is no leading dot.
docker build . -t appdocker run -v $(pwd):/mnt -e 'APP_PATH=/mnt/example.json' -it app