@nclabs/nestjs-rpc-module

nestjs-nclabs-rpc-module

Utilitário NestJS para configuração de rotas e cache em microsserviços. Utilizado especificamente para projetos nclabs

Instalação

npm i @nclabs/rpc-module

Configuração

# Environment variables

...

SERVICE_NAME= ## <indicar no environment do docker compose>


# ##################################################################### # 
#                                   NATS                                #
# ##################################################################### # 
NATS_HOST=<host>
NATS_PORT=<port>


# ##################################################################### # 
#                                   REDIS                               #
# ##################################################################### # 
REDIS_HOST=<host>
REDIS_PORT=<port>
REDIS_PASSWORD=<password>


# ##################################################################### # 
#                                   CACHE                               #
# ##################################################################### # 
CACHE_PREFIX=API-CACHE
CACHE_TTL=600
CACHE_HIT_LOG=true

...

Modulo

// app.module.ts

...
import { NclabsRpcModule } from '@nclabs/rpc-module';

@Module({
  imports: [    
    // ...
    NclabsRpcModule.register({ cache: true }),
    // ...
  ],
  // ...
})
export class AppModule {}

Recursos

Recurso	Tipo	Uso	Observação
NclabsAction	Decorator	Controller	Configura requisições RPC e HTTP (opcional)
NclabsEvent	Decorator	Controller	Configura envio de eventos RPC
NclabsCtx	Decorator	Controller Service	Acessa informações do contexto do microserviço
INclabsContext	Interface	*	Tipo de contexto do microserviço
NclabsRpcClientService	Provider	Controller Service	Métodos para requisição de microserviços externos (RPC conf)
NclabsCacherService	Provider	Controller Service	Métodos para o tratamento manual do cache
NclabsException	Lib	Promise Approach	Trata exceções do microserviço
NclabsRxjsErrorHandler	Lib	Observable Approach	Trata exceções do microserviço (catchError)
INclabsException	Interface	*	Tipo de exceção do microserviço

Controller - Method Configuration

// app.controller.ts

...

@Controller()
export class AppController {

  ...

  @NclabsAction({
    name: 'your-action-name',
    rest: {
      methods: ['GET', 'POST'],
      path: '/your-path',
    },
    cache: {
      keys: ['#headers.authorization', '#params.id', 'some-key'],
      ttl: 1200, // seconds
    },
  })
  youMethodName(@NclabsCtx() context: NclabsContext) {
    // Do something
    return;
  }

  ...

• RPC: O método poderá ser requisitado pelo padrão service.name

  Onde:
  
  - service = SERVICE_NAME  (definido no environment do docker compose)
  - name    = your-action-name (configurado no decorator do método)
  

• HTTP: A configuração rest do decorator irá disponibilizar 1 rotas de acesso HTTP para cada method:

  - GET /your-path
  - POST /your-path
  

• CACHE: A configuração cache irá disponibilizar um cache para o retorno da requisição com as chaves especificadas no keys e com o TTL especificado no ttl.

  A chave do cache será criada concatenando:
  
    1. PATTERN       = <SERVICE_NAME.name> ou <SERVICE_NAME.method.path>
    2. authorization = informação do header `authorization`
    3. id            = atributo `id` do objeto `data` do contexto
    4. some-key      = texto estático
  
   KEY GERADA: 
   
      PATTERN.Bearer A8D---.123.some-key
  

Contexto

// app.controller.ts
// app.service.ts

...

@Controller()
// ou
@Injectable()

  ...

  youMethod(@NclabsCtx() context: NclabsContext) {

    const { meta, headers, data } = context;

    // Meta:    Informações do microserviço (handler, subject e cadeia de chamadas)
    // Headers: Header do request
    // Data:    Body do request mesclado com os query parameters

    return;
  }

  ...

Client Service

// app.controller.ts
// app.service.ts

...

@Controller()
// ou
@Injectable()

  ...

  constructor(
    private readonly clientRpc: NclabsRpcClientService,
  ) {}

  ...

  youMethod(@NclabsCtx() context: NclabsContext): Obserable<Person> {

    const payload = { 
      name: 'John' 
    }; 

    return this.clientRpc.call('other-service.action', payload, context); 

  }

  ...

Exceptions

// app.controller.ts
// app.service.ts

...

@Controller()
// ou
@Injectable()

  ...


  /**
   * 
   * 
   */ 
  youMethod(token: string, includeG5 = false): Observable<IUser> {

    const url = `${baseUrl}platform/user/queries/getUser`;

    const headers = {
      Authorization: `Bearer ${token}`,
    };

    return this.httpService.get<IUser>(url, { headers }).pipe(
      // get data
      map((response: AxiosResponse<IUser>) => response.data),
      // append authentication
      map((data: IUser) => ({ ...data, authentication: `Bearer ${token}` })),
      // map response to IUser
      map(this._mapResponseToIUser),
      // generate password for G5
      map((user: IUser) => {
        if (includeG5) {
          const password = this._generateEncryptPassword(user.username);
          user.password = password;
          user.encryption = 2;
        }
        return user;
      }),
      catchError(NclabsRxjsErrorHandler),
    );
  }


  /**
   * 
   *  Generate password for G5
   * 
   */
  private _generateEncryptPassword(username: string): string {

    // create/get password

    if (!password || password === 'null') {
      const error = {
        code: 401,
        type: 'UNAUTHORIZED',
        message: 'Não foi possível gerar a senha encriptada do Senior G5',
        error: {
          jar: 'crypt.jar',
          encrypt: 'CBC',
          user: username,
          date: dt.toLocaleString('pt-BR', options).replace(',', ''),
        },
      };
      throw new NclabsException(error);
    }

    // do something

    return encryptedPassword;
  }

  ...