Deploying

Docker deployment

The example below shows how to use moleculer-runner and Docker to deploy Moleculer services across multiple containers.

Note that moleculer-runner is capable of reading environment variables, which are heavily used in Docker deployments. More info about runner’s configuration loading logic.

The Docker files shown here are from moleculer-demo project.

For mode detailed info about Docker and Kubernetes please check the docker demo repository.

Dockerfile

Dockerfile to run Moleculer services

FROM node:current-alpine

ENV NODE_ENV=production

RUN mkdir /app
WORKDIR /app

COPY package.json package-lock.json ./

RUN npm ci --omit=dev

COPY . .

CMD ["npm", "start"]

Docker Compose

Docker compose files to run Moleculer services with NATS & Traefik (load balancing the API Gateway)

Set the necessary environment variables.
docker-compose.env

NAMESPACE=
LOGGER=true
LOGLEVEL=info
SERVICEDIR=services # Inform moleculer runner about the location of service files

TRANSPORTER=nats://nats:4222 # Set transporter in all containers
MONGO_URI=mongodb://mongo/project-demo # Set MongoDB URI

Configure the containers.
docker-compose.yml

services:

  api:
    build:
      context: .
    image: project-demo
    env_file: docker-compose.env
    environment:
      SERVICES: api # Moleculer Runner will start only the 'api' service in this container
      PORT: 3000    # Port of API gateway
    depends_on:
      - nats
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.api-gw.rule=PathPrefix(`/`)"
      - "traefik.http.services.api-gw.loadbalancer.server.port=3000"
    networks:
      - internal

  greeter:
    build:
      context: .
    image: project-demo
    env_file: docker-compose.env
    environment:
      SERVICES: greeter # Moleculer Runner will start only the 'greeter' service in this container
    depends_on:
      - nats
    networks:
      - internal

  products:
    build:
      context: .
    image: project-demo
    env_file: docker-compose.env
    environment:
      SERVICES: products # Moleculer Runner will start only the 'products' service in this container
    depends_on:
      - mongo
      - nats
    networks:
      - internal

  mongo:
    image: mongo:4
    volumes:
      - data:/data/db
    networks:
      - internal

  nats:
    image: nats:2
    networks:
      - internal

  traefik:
    image: traefik:v3
    command:
      - "--api.insecure=true" # Don't do that in production!
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
    ports:
      - 3000:80
      - 3001:8080
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
    networks:
      - internal
      - default

networks:
  internal:

volumes:
  data:

Start containers

$ docker compose up -d

Access your app on http://<docker-host>:3000/. Traefik dashboard UI on http://<docker-host>:3001/

Kubernetes deployment

Moleculer needs no special Kubernetes integration: a Moleculer node is a plain container (like the one built from the Dockerfile above), so you deploy it as a regular Deployment and let the nodes find each other through the transporter (e.g. a NATS service in the cluster). For community examples see dkuida‘s step by step tutorial, lehno‘s code samples, tobydeh‘s deployment guide and the related discussion.