When-Then Engine

A straight forward rule engine build in spring-native with graalvm-native build

Env Setup

Check out BUILD document for setting up dev environment

Build

• Build by running - mvn -Pnative-image clean package
• Binary as target/wte

Test

• Go to target folder and
• Run ./wte -Dserver.port=8081 to verify the system running

Docker build and exe

• Set docker memory to high value, since the compilation is AOT and requires greater memory
  • Check for error 137 - shows memory insufficiency
• Run docker-compose build
• Run docker swarm init
  • Note down the join-token
  • Run docker swarm join-token to get the token again
• Run docker stack deploy -c dcoker-compose.yml re

Scale

• Run docker service ls -> find the running re service
• Run docker service scale <service name>=3
• Run docker service ls to verify new replicas deployed

Sample Requests

{
  "rules" : [
    {
      "when": {
        "lhs": 2,
        "operation": "EQ",
        "rhs": 2
      },
      "then": {
        "id": 2,
        "name" : "Test -2"
      }
    },
    {
      "when": {
        "lhs": "$user.points$",
        "operation": "GTE",
        "rhs": 1000
      },
      "data": {
        "user":{
          "points" : 9999
        }
      },
      "then": {
        "id": 3,
        "name" : "Test - 3"
      }
    }
  ]
}