project-demo

This is a Moleculer-based microservices project. Generated with the Moleculer CLI.

Template architecture

Moleculer supports different deployment modes. The figures below represent the deployment and production architectures. Switching between the architectures is automatically handled by moleculer. To run in dev mode use npm run dev, for production mode run npm run dc:up.

Development architecture view

flowchart LR
    classDef svc fill:lightblue
    classDef brk fill:#fff2cc
    classDef ext fill:violet

    U(User browser)
    U --> A
    
    subgraph node1 [Monolith Node]
    style node1 fill:#dae8fc,stroke:#c9d7eb
    A("**API Gateway**
    -HTTP Server
    -GraphQL Server
    -Socket.IO Server
    ")
    A --> B

    B((Service Broker))

    G(Greeter Service):::svc
    B <--> G
    
    P(Products Service):::svc
    DA(Database Adapter)
    B <--> P
    P <--> DA
    DB[(MongoDB server)]:::ext
    DA <--> DB
    
    I(Inventory Service):::svc
    CH(Channel Adapter)
    B <--> I
    I <--> CH
    CH <--> Redis:::ext
    
    O(Orders Service):::svc
    WF(Workflow Adapter)
    B <--> O
    O <--> WF
    WF <--> Redis:::ext
    
    end

    style B fill:orange
    style A fill:lightgreen
    style U fill:lightcyan
    style node1 fill:#dae8fc,stroke:#c9d7eb

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Production architecture view

flowchart LR
    classDef svc fill:lightblue
    classDef brk fill:#fff2cc
    classDef ext fill:violet

    TX{ NATS Transporter}:::ext

    subgraph node1 [Node 1]
    style node1 fill:#dae8fc,stroke:#c9d7eb
    A("**API Gateway**
    -HTTP Server
    -GraphQL Server
    -Socket.IO Server
    ")
    style A fill:lightgreen
    B1((Service Broker)):::brk
    A --> B1
    end
    B1 --> TX
    U(User browser)
    style U fill:lightcyan
    U --> A

    subgraph node2 [Node 2]
    style node2 fill:#dae8fc,stroke:#c9d7eb
    B2((Service Broker)):::brk
    G(Greeter Service):::svc
    B2 <--> G
    end
    TX --> B2

    subgraph node3 [Node 3]
    style node3 fill:#dae8fc,stroke:#c9d7eb
    B3((Service Broker)):::brk
    P(Products Service):::svc
    DA(Database Adapter)
    B3 <--> P
    P <--> DA
    end
    TX --> B3
    DB[(MongoDB server)]:::ext
    DA <--> DB

    subgraph node4 [Node 4]
    style node4 fill:#dae8fc,stroke:#c9d7eb
    B4((Service Broker)):::brk
    I(Inventory Service):::svc
    CH(Channel Adapter)
    B4 <--> I
    I <--> CH
    end
    TX --> B4
    CH <--> Redis:::ext

    subgraph node5 [Node 5]
    style node5 fill:#dae8fc,stroke:#c9d7eb
    B5((Service Broker)):::brk
    O(Orders Service):::svc
    WF(Workflow Adapter)
    B5 <--> O
    O <--> WF
    end
    TX --> B5
    WF <--> Redis:::ext

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Usage

Start the project with npm run dev command. After starting, open the http://localhost:3000/ URL in your browser. On the welcome page you can test the generated services via API Gateway and check the nodes & services.

Open the http://localhost:3000/graphql URL in your browser to access the GraphQL Playground.

In the terminal, try using Moleculer REPL by running the following commands:

• nodes - List all connected nodes.
• services - List all the available services.
• actions - List all registered service actions.
• info - List node info (e.g., IP, memory usage).
• call greeter.hello - Call the greeter.hello action.
• call greeter.welcome --name John - Call the greeter.welcome action with the name parameter.
• call products.list - List the products (call the products.list action).

Services

• api: API Gateway services
• greeter: Sample service with hello and welcome actions.
• products: Sample DB service. To use with MongoDB, set DB_URI environment variables and install MongoDB adapter with npm install mongodb.
• inventory: Sample service with a single channel handler that uses persistent queues to reliably process the messages.
• workflows: Workflow sample service.

Mixins

• db.mixin: Database access mixin for services. Based on moleculer/database

Useful links

• Moleculer website: https://moleculer.services/
• Moleculer Documentation: https://moleculer.services/docs/0.15/
• Moleculer Database service: https://github.com/moleculerjs/database
• Moleculer API Gateway: https://moleculer.services/docs/0.15/moleculer-web.html
• Moleculer GraphQL Gateway: https://github.com/moleculerjs/moleculer-apollo-server
• Moleculer Socket.IO Gateway: https://github.com/moleculerjs/moleculer-io
• Moleculer Channels: https://github.com/moleculerjs/moleculer-channels
• Moleculer Workflows: https://github.com/moleculerjs/workflows

NPM scripts

• npm run dev: Start development mode (load all services locally with hot-reload & REPL)
• npm run start: Start production mode (set SERVICES env variable to load certain services)
• npm run cli: Start a CLI and connect to production. Don't forget to set production namespace with --ns argument in script
• npm run lint: Run ESLint
• npm run ci: Run continuous test mode with watching
• npm test: Run tests & generate coverage report
• npm run dc:up: Start the stack with Docker Compose
• npm run dc:down: Stop the stack with Docker Compose