Enabling mongo transactions using docker-compose

README.md

If you develop against of containerized mongo instance using the official Docker Mongo image and make attempt to use transactions, you will most probably face the following error:

com.mongodb.MongoCommandException: Command failed with error 20 (IllegalOperation): 'Transaction numbers are only allowed on a replica set member or mongos' on server localhost:28017. The full response is {"ok": 0.0, "errmsg": "Transaction numbers are only allowed on a replica set member or mongos", "code": 20, "codeName": "IllegalOperation"}

This single docker-compose.yaml will solve the problem by creating replica set out of single node.

docker-compose.yaml

version: '3.9'

services:
  mongodb:
    image: mongo:5
    command: --replSet rs0
    ports:
      - "28017:27017"
    environment:
      MONGO_INITDB_DATABASE: attachment-api-local-dev
    healthcheck:
      test: echo 'db.runCommand("ping").ok' | mongo localhost:27017/admin --quiet
      interval: 2s
      timeout: 3s
      retries: 5

  mongo-init:
    image: mongo:5
    restart: "no"
    depends_on:
      mongodb:
        condition: service_healthy
    command: >
      mongo --host mongodb:27017 --eval
      '
      rs.initiate( {
         _id : "rs0",
         members: [
            { _id: 0, host: "localhost:27017" }
         ]
      })
      '