feat: ✨ add AuthGuard

apps/gateway/src/app/app.module.ts

@@ -1,4 +1,4 @@
-import { IntrospectAndCompose } from '@apollo/gateway';
+import { IntrospectAndCompose, RemoteGraphQLDataSource } from '@apollo/gateway';
 import { gatewayConfig, userAppConfig } from '@shared/config';
 import { ApolloGatewayDriver, ApolloGatewayDriverConfig } from '@nestjs/apollo';
 import { Module } from '@nestjs/common';
@@ -31,6 +31,20 @@ import { AppService } from './app.service';
                 },
               ],
             }),
+            buildService: ({ url = '' }) => {
+              return new RemoteGraphQLDataSource({
+                url,
+                willSendRequest({ request, context }) {
+                  // rebuild header
+                  if (Object.keys(context).length > 0 && request.http) {
+                    request.http.headers.set(
+                      'Authorization',
+                      context['req']['headers']['authorization'],
+                    );
+                  }
+                },
+              });
+            },
           },
         };
       },

apps/users/src/app/app.module.ts

@@ -37,6 +37,9 @@ import { AppService } from './app.service';
       playground: process.env['NODE_ENV'] !== 'production',
       sortSchema: true,
       plugins: [ApolloServerPluginInlineTrace()],
+      context: ({ req }: { req: Request }) => {
+        return { headers: req?.headers };
+      },
     }),
     UsersModule,
     AuthModule,

libs/auth/interface-adapters/src/index.ts

@@ -1 +1,3 @@
+export * from './lib/guard/auth.guard';
+
 export * from './lib/auth.module';

libs/auth/interface-adapters/src/lib/guard/auth.guard.ts

@@ -0,0 +1,44 @@
+import {
+  CanActivate,
+  ExecutionContext,
+  Injectable,
+  UnauthorizedException,
+} from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import { JwtService } from '@nestjs/jwt';
+import { Request } from 'express';
+
+@Injectable()
+export class AuthGuard implements CanActivate {
+  constructor(
+    private jwtService: JwtService,
+    private configService: ConfigService,
+  ) {}
+
+  async canActivate(context: ExecutionContext): Promise<boolean> {
+    const authConfig = this.configService.get('auth');
+    const request = context.switchToHttp().getRequest();
+    const token = this.extractTokenFromHeader(request);
+
+    if (!token) {
+      throw new UnauthorizedException();
+    }
+
+    try {
+      const payload = await this.jwtService.verifyAsync(token, {
+        secret: authConfig.secret,
+      });
+      // 💡 We're assigning the payload to the request object here
+      // so that we can access it in our route handlers
+      request['user'] = payload;
+    } catch {
+      throw new UnauthorizedException();
+    }
+    return true;
+  }
+
+  private extractTokenFromHeader(request: Request): string | undefined {
+    const [type, token] = request.headers.authorization?.split(' ') ?? [];
+    return type === 'Bearer' ? token : undefined;
+  }
+}

libs/users/interface-adapters/src/lib/resolver/users.resolver.ts

@@ -1,3 +1,5 @@
+import { AuthGuard } from '@auth/interface-adapters';
+import { UseGuards } from '@nestjs/common';
 import { Args, ID, Query, Resolver } from '@nestjs/graphql';
 import { UsersService } from '@users/application';
 import { User } from '@users/domain';
@@ -8,9 +10,12 @@ import { UserDto } from '../dto/user.dto';
 export class UsersResolver {
   constructor(private usersService: UsersService) {}
 
+  @UseGuards(AuthGuard)
   @Query(() => UserDto, { nullable: true })
-  async getUser(@Args({ name: 'id', type: () => ID }) id: string): Promise<UserDto | null> {
-    const user: User| null = await this.usersService.findById(id);
+  async getUser(
+    @Args({ name: 'id', type: () => ID }) id: string,
+  ): Promise<UserDto | null> {
+    const user: User | null = await this.usersService.findById(id);
 
     if (!user) {
       return null;

libs/users/interface-adapters/src/lib/users.module.ts

@@ -1,4 +1,5 @@
 import { Module } from '@nestjs/common';
+import { JwtService } from '@nestjs/jwt';
 import { DatabaseModule } from '@shared/infrastructure-mongoose';
 import { UsersService, GetUserByIdUseCase, GetUserByEmailUseCase } from '@users/application';
 import {
@@ -15,6 +16,7 @@ import { UsersResolver } from './resolver/users.resolver';
   providers: [
     UsersResolver,
     UsersService,
+    JwtService,
     GetUserByIdUseCase,
     GetUserByEmailUseCase,
     {