Manager Vending Machines

The Manager Vending Machine is a centrally managed vending system that uses a GRPC server written in Golang. It offers easy setup and maintenance, fast and reliable communication, and efficient vending operations management.

Running Vending Machines

To test the vending machine, follow these steps:

1- Compile the code:

make dependencies
make vendingd

2- Run the vending machine (you can change the config-file and run multiple machines):

./vendingd machine -c  local.vending.1.yaml
./vendingd machine -c  local.vending.2.yaml

3- Run the manager to attach to the machine:

./vendingd manager -c local.sample.yaml

4- Send a command by example (uncomment the command type and change it):

go run ./examples/client.go -b localhost:10000
go run ./examples/client.go -b localhost:10001

Testing and Linting

Before creating a pull request, make sure you run these commands:

make lint-fix && make lint-get && make lint
make test
make race

Running the Project with Docker Compose

To simplify the process of running our project, we have included a docker-compose.yml file that defines the required services and configurations. To start the project, simply run the following command in your terminal:

docker-compose up

This will start all the necessary services and dependencies, allowing you to interact with the program.

To send commands to the program, you can use the client.go file located in the examples directory. Uncomment the command type that you want to use and change the -b flag to the appropriate address.

For example, to send a command to a server running on localhost port 10000, you would run:

go run ./examples/client.go -b localhost:10000

Design Patterns and Architecture

The following design patterns and architecture used for managing a distributed vending machine:

1-Microservices Architecture: A microservices architecture can be used to decompose the vending machine system into small, independent services that can communicate with each other using APIs. This architecture can improve scalability, fault tolerance, and maintainability.

2-Command Design Pattern: The Command design pattern can be used to encapsulate actions taken by the vending machine system in a command object. Each command can represent a specific action, such as adding an item to the inventory, processing a payment, or dispensing an item. This pattern can provide a flexible and extensible way to manage the vending machine's behavior.

3-Observer Design Pattern: The Observer design pattern can be used to notify the vending machine system when an event occurs, such as a payment being processed or an item being dispensed. This pattern can provide a decoupled way to manage the vending machine's behavior and improve maintainability.

4-State Design Pattern: The state pattern can be used to model the different states that a vending machine can be in, such as "idle," "dispensing," and "payment." Each state would be represented by a separate class, and the vending machine object would transition between states as it performs different operations.

5-Domain-Driven Design: Domain-Driven Design (DDD) can be used to model the vending machine system based on its domain concepts, such as items, payments, and dispensing. This approach can help to create a clear understanding of the system's behavior and requirements and can guide the design of the system's architecture and APIs.

6-Load Balancing: Load balancing can be used to distribute the workload across multiple instances of the vending machine system. This can improve scalability and fault tolerance by ensuring that the system can handle a large number of requests and can recover from failures without affecting the user experience.

7-GRPC Service: GRPC is a communication framework that allows vending machines to communicate with a central server or set of servers. The GRPC service would define the messages and operations that the server can perform on the vending devices, such as dispensing products and updating inventory.

These design patterns and architecture can provide a flexible and maintainable way to manage the complex stateful systems of distributed vending machines.