This is vert.x based distributed java stomp websocket gateway server with kafka integration

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Features:

• Websocket
• STOMP
• Apache kafka (for interservice communication)
• Vert.X cluster
• Monitoring (micrometer, prometheus)
• Changelog.md generation (for cicd/release process)
• Conventional commits

Usage

The server sources already contain static html websocket resources demo available at http://localhost:8080. Run all required containers:

docker compose -f ./docker/all.yml up -d

Then run java app. You can produce message to websocket_gateway_output_topic using redpanda console which available at http://localhost:8085

Example of output message:

{
  "sender": "sender sample",
  "stompChannel": "/example_output",
  "message": "message sample",
  "createdAt": "...",
  "recipient": "0a32e82b-45e9-4250-b430-e4acb4980746"
}

Example of input (ws) message:

{
  "sender": "sender sample",
  "message": "message sample",
  "createdAt": "..."
}

Notice, input messages are not conceived to be responded

Recipient is UUID ws session indentifier printed in server console when new client is connected

Metrics

Prometheus metrics are enabled by default and available at /prometheus endpoint JSON-encoded metrics are available at /metrics

Requirements

Kafka topic retention

All kafka topic used by websocket gateway should be adjusted with low retention.ms. One minute is enough

Environment variables

Following variables should be provided:

• KAFKA_BOOTSTRAPSERVERS - optional, required for cloud setup
• APP_INPUT_STOMP_KAFKA_MAPPING - required for stomp-kafka input mapping. Format: "/stomp_channel1:kafka_topic1","/stomp_channel2:kafka_topic2". Example for startup - APP_INPUT_STOMP_KAFKA_MAPPING="/example_input:test_topic"