Building microservices with Node.js involves several steps, namely:
1. Design your microservices: Before you start building, you need to design your microservices. Identify the functionalities that can work independently, and create a design plan for each functionality.
1. Set Up Your Development Environment: You’ll need Node.js installed to use it for your microservices. You can download it from its official site if you haven’t already.
1. Create Your Project: Create a new directory in your system to hold your project. You can use Express.js, a Node.js framework, to create the application. To do this, after creating the directory, go to its location in your terminal, and use npm (node package manager), which is installed automatically with Node.js, to install Express.
\`\`\` mkdir microservice cd microservice npm init —yes npm install express —save \`\`\` Afterwards, create a new file called ‘app.js’. You can use ‘touch’ command on terminal to do this. \`\`\` touch app.js \`\`\`1. Develop Your Microservice: Write a simple microservice in the ‘app.js’. Below is an example of a microservice that will return a simple message.
\`\`\` const express = require(‘express’); const app = express(); const port = 3000; app.get(‘/’, (req, res) => { res.send(‘Hello from Microservice’); }); app.listen(port, () => { console.log(`Microservice listening at http://localhost:${port}`); }); \`\`\` Run your microservice using `node app.js` in the terminal and open your browser to `http://localhost:3000`. You should see `Hello from Microservice`.1. Scaling Your Microservice: You can create more microservices following the steps above. Just make sure to use a different port for each one.
1. Communication Between Microservices: Use HTTP/HTTPS protocols for communication. Calling a service from another can be achieved by sending HTTP requests.
1. Setup Database: Databases can hold the data needed by your microservices. Each microservice should have its own database to ensure they remain decoupled.
1. Implement APIs: APIs can be used to expose your microservices to clients. For each microservice, designate specific routes and handlers.
1. Error Handling: Make sure to catch any promising error and handle it properly.
1. Testing: Use testing tools like Mocha or Jest to write unit tests for each microservice.
1. Deployment: Deploy each microservice separately. Use containers like Docker to encapsulate your microservices, making them easier to manage and deploy. Use orchestration tools like Kubernetes for handling multiple containers.
Remember, the key concept of microservices is decoupling. Each microservice should have a single responsibility and should be able to operate independently.
