Save assets and generate presigned URLs

migrations/1697978452568-createAsset.ts

@@ -0,0 +1,39 @@
+import {
+    MigrationInterface,
+    QueryRunner,
+    Table,
+} from "typeorm"
+
+export class CreateAsset1697978452568 implements MigrationInterface {
+
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.createTable(
+            new Table({
+                name: "asset",
+                columns: [
+                    {
+                        name: "id",
+                        type: "int",
+                        isPrimary: true,
+                        isGenerated: true,
+                        generationStrategy: 'increment',
+                    },
+                    {
+                        name: "filename",
+                        type: "varchar",
+                    },
+                    {
+                        name: "uid",
+                        type: "varchar",
+                    },
+                ],
+            }),
+            true,
+        )
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.dropTable("asset")
+    }
+
+}

package.json

@@ -26,6 +26,7 @@
   },
   "dependencies": {
     "@aws-sdk/client-s3": "^3.433.0",
+    "@aws-sdk/s3-request-presigner": "^3.433.0",
     "@nestjs/common": "^10.0.0",
     "@nestjs/config": "^3.1.1",
     "@nestjs/core": "^10.0.0",

src/companies/assets.service.ts

@@ -0,0 +1,53 @@
+import { Injectable } from '@nestjs/common';
+import { CreateAssetDto } from './dto/create-asset.dto';
+import { EntityManager, Repository } from 'typeorm';
+import { Asset } from './entities/asset.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { getSignedUrl } from '@aws-sdk/s3-request-presigner'
+import { S3Client, GetObjectCommand } from "@aws-sdk/client-s3";
+import { ConfigService } from "@nestjs/config";
+
+@Injectable()
+export class AssetsService {
+  constructor(
+    @InjectRepository(Asset)
+    private readonly assetsRepository: Repository<Asset>,
+    private readonly entityManager: EntityManager,
+    private readonly configService: ConfigService,
+  ) {}
+
+  async create(createAssetDto: CreateAssetDto) {
+    const asset = new Asset({
+      ...createAssetDto,
+    });
+    await this.entityManager.save(asset);
+  }
+
+  async findOne(id: number) {
+    const asset = await this.assetsRepository.findOne({
+      where: { id },
+    });
+
+    const s3 = new S3Client({
+      region: this.configService.getOrThrow('AWS_REGION'),
+      credentials: {
+        accessKeyId: this.configService.getOrThrow('AWS_ACCESS_KEY_ID'),
+        secretAccessKey: this.configService.getOrThrow('AWS_SECRET_KEY_ID'),
+      },
+    });
+
+    const bucketName = this.configService.getOrThrow('AWS_BUCKET');
+    const objectKey = asset.uid;
+    const expirationInSeconds = 3600;
+
+    // Generate the pre-signed URL
+    const command = new GetObjectCommand({
+      Bucket: bucketName,
+      Key: objectKey,
+    });
+
+    const url = await getSignedUrl(s3, command, { expiresIn: expirationInSeconds });
+
+    return { url, filename: asset.filename };
+  }
+}

src/companies/companies.controller.ts

@@ -17,10 +17,13 @@ import { UpdateCompanyDto } from './dto/update-company.dto';
 import { Pagination } from './../paginate';
 import { Company } from './entities/company.entity';
 import { FileInterceptor } from '@nestjs/platform-express';
+import { AssetsService } from './assets.service';
 
 @Controller('companies')
 export class CompaniesController {
-  constructor(private readonly companiesService: CompaniesService, private readonly fileUploadService: FileUploadService) {}
+  constructor(private readonly companiesService: CompaniesService,
+    private readonly fileUploadService: FileUploadService,
+    private readonly assetsService: AssetsService) {}
 
   @Post()
   create(@Body() createCompanyDto: CreateCompanyDto) {
@@ -55,4 +58,9 @@ export class CompaniesController {
   uploadFile(@UploadedFile() file: Express.Multer.File) {
     return this.fileUploadService.uploadFile(file.buffer, file.originalname);
   }
+
+  @Get('assets/:id')
+  findOneAsset(@Param('id') id: string) {
+    return this.assetsService.findOne(+id);
+  }
 }

src/companies/companies.module.ts

@@ -3,11 +3,13 @@ import { CompaniesService } from './companies.service';
 import { CompaniesController } from './companies.controller';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { Company } from './entities/company.entity';
+import { Asset } from './entities/asset.entity';
 import { FileUploadService } from './file.upload.service';
+import { AssetsService } from './assets.service';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Company])],
+  imports: [TypeOrmModule.forFeature([Company, Asset])],
   controllers: [CompaniesController],
-  providers: [CompaniesService, FileUploadService],
+  providers: [CompaniesService, FileUploadService, AssetsService],
 })
 export class CompaniesModule {}

src/companies/dto/create-asset.dto.ts

@@ -0,0 +1,4 @@
+export class CreateAssetDto {
+  filename: string;
+  uid: string;
+}

src/companies/entities/asset.entity.ts

@@ -0,0 +1,17 @@
+import { Column, Entity, PrimaryGeneratedColumn } from 'typeorm';
+
+@Entity()
+export class Asset {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Column()
+  filename: string;
+
+  @Column()
+  uid: string;
+
+  constructor(asset: Partial<Asset>) {
+    Object.assign(this, asset);
+  }
+}

src/companies/file.upload.service.ts

@@ -2,12 +2,13 @@ import { Injectable } from "@nestjs/common";
 import { ConfigService } from "@nestjs/config";
 import { S3Client, PutObjectCommand } from "@aws-sdk/client-s3";
 import { v4 as uuid } from 'uuid';
+import { AssetsService } from './assets.service';
 
 @Injectable()
 export class FileUploadService {
-    constructor(private readonly configService: ConfigService) {}
+    constructor(private readonly configService: ConfigService, private readonly assetsService: AssetsService) {}
 
-    async uploadFile(dataBuffer: Buffer, fileName: string): Promise<string> {
+    async uploadFile(dataBuffer: Buffer, fileName: string) {
       const s3 = new S3Client({
         region: this.configService.getOrThrow('AWS_REGION'),
         credentials: {
@@ -25,6 +26,6 @@ export class FileUploadService {
       });
 
       const result = await s3.send(command);
-      return fileS3Name;
+      return this.assetsService.create({ filename: fileName, uid: fileS3Name });
     }
 }