NodeJS Microservice Remote Middleware lib for Microservices lib

!npm
!GitHub
!GitHub package.json dependency version (dev dep on branch)


Install

``bash
npm i --save @lomray/microservice-remote-middleware
`

Usage

1. Create server remote middleware instance. It might be any microservice but only one.
`typescript
import { Microservice } from '@lomray/microservice-remote-middleware';
import { RemoteMiddlewareServer } from '@lomray/microservice-remote-middleware';
import { createConnection } from 'typeorm';

const microservice = Microservice.create({ name: 'configuration' });

// Add this endpoint for testing remote middleware
microservice.addEndpoint('example-method', ({ hello }) => ({ hello }));

const result = async () => {
try {
// In this case we are use TYPEORM
const connection = await createConnection();
// Get Middleware repository for store middlewares data
const repository = connection.getRepository(Middleware)

// Enable remote middleware
const remoteMiddleware = RemoteMiddlewareServer.create(microservice, repository)
.addRegisterEndpoint()
.addObtainEndpoint();

/**
* Add microservice method like remote middleware.
* In future, you can create CRUD for this actions.
* For example:
*/
// 1. Create method for register like middleware: configuration.middleware-method
microservice.addEndpoint('middleware-method', () => ({ hello: 'middleware world' }), {
isDisableMiddlewares: true,
isPrivate: true,
});
// 2. Register remote middleware on gateway microservice. This middleware will be triggered only for requests to any configuration methods.
await remoteMiddleware.add(
'configuration',
'middleware-method',
'gateway',
'configuration.*',
);

await microservice.start();
} catch (e) {
console.info('\x1b[31m%s\x1b[0m', Failed to start microservice: ${e.message as string});
}
};

export default result();
`
2. Create client remote middleware instance. It might be any microservice.
`typescript
import { Gateway } from '@lomray/microservice-remote-middleware';
import { RemoteMiddlewareClient } from '@lomray/microservice-remote-middleware';

const microservice = Gateway.create({ name: 'gateway' });

const result = async () => {
try {
// Enable remote middleware
await RemoteMiddlewareClient.create(microservice)
.addRegisterEndpoint()
.obtainMiddlewares();

await microservice.start();
} catch (e) {
console.info('\x1b[31m%s\x1b[0m', Failed to start microservice: ${e.message as string});
}
};

export default result();
`
3. That is all. Check it:
`bash
curl -X POST http://127.0.0.1:3000
-H 'Content-Type: application/json'
-d '{"id":"unique-id-1","method":"configuration.example-method","params":{"hello":"world"}}'
`

You can run any microservice and create remote middleware client. Check out the examples below to get the desired result:


`typescript
// Add remote middleware on any microservices methods (note: this is gateway microservice)
await remoteMiddleware.add(
'configuration',
'middleware-method',
'gateway',
'*',
);

// Add remote middleware on specific microservice method (note: this is gateway microservice)
await remoteMiddleware.add(
'configuration',
'middleware-method',
'gateway',
'users.list',
);

// Also you can add remote middleware directly to microservice
await remoteMiddleware.add(
'configuration',
'middleware-method',
'users',
'users.create',
);

// Just one more example :) Add authentication for requests (you should have authentication microservice)
await remoteMiddleware.add(
'authentication',
'middleware-authenticate',
'gateway',
'*',
);

// Or you can chose another middleware response strategy and convert input/output data
await remoteMiddleware.add(
'authentication',
'get-jwt',
'gateway',
'*',
{
type: MiddlewareType.response,
strategy: MiddlewareStrategy.same,
isRequired: true,
convertResult: {
// here we get user id from users microservice response and pass like param to 'get-jwt' method
'user.id': 'userId'
}
}
);
``