The nestjs-multer-extended's intro from sdinesh86

Features

Single file upload to an Amazon S3 bucket
Support for dynamic paths, upload files wherever you want!
Generate thumbnail image along with the original
Resize single image or even make it into different sizes
Load AWS S3 configuration at runtime

Installation

NPM

$ npm i -s nestjs-multer-extended

Yarn

$ yarn add nestjs-multer-extended

Getting started

Once the installation process is complete, we can import the module either synchronously or asynchronosly into the root AppModule.

Synchronous configuration

import { Module } from '@nestjs/common';
import { MulterExtendedModule } from 'nestjs-multer-extended';

@Module({
  imports: [
    MulterExtendedModule.register({
      accessKeyId: 'YOUR_AWS_ACCESS_KEY_ID',
      secretAccessKey: 'YOUR_AWS_SECRET_ACCESS_KEY',
      region: 'AWS_REGION_NEAR_TO_YOU',
      bucket: 'YOUR_S3_BUCKET_NAME',
      basePath: 'ROOT_DIR_OF_ASSETS',
      fileSize: 1 * 1024 * 1024,
    }),
  ],
})
export class AppModule {}

Asynchronous configuration

In this example, the module integrates with the awesome nestjs-config package.

useFactory should return an object with MulterExtendedS3Options interface or undefined.

import { Module } from '@nestjs/common';
import { MulterExtendedModule } from 'nestjs-multer-extended';
import { ConfigService } from 'nestjs-config';

@Module({
  imports: [
    MulterExtendedModule.registerAsync({
      useFactory: (config: ConfigService) => config.get('s3'),
      inject: [ConfigService],
    }),
  ],
})
export class AppModule {}

Note: You can import this module from not only the root module of your app but also from other feature modules where you want to use it.

To upload a single file, simply tie the AmazonS3FileInterceptor() interceptor to the route handler and extract file from the request using the @UploadedFile() decorator.

import { Controller, Post, UseInterceptors, UploadedFile } from '@nestjs/common';
import { AmazonS3FileInterceptor } from 'nestjs-multer-extended';

@Controller()
export class AppController {

  @Post('upload')
  @UseInterceptors(AmazonS3FileInterceptor('file'))
  uploadFile(@UploadedFile() file) {
    console.log(file);
  }
}

In this example, uploadFile() method will upload a file under the base path you have configured earlrier.

The AmazonS3FileInterceptor() decorator takes two arguments:

fieldName: string that supplies the name of the field from the HTML form that holds a file.
options: optional object of type MulterExtendedOptions. (mode details here)

What if you wanted to upload a file in a different location under the base path? Thankfully, AmazonS3FileInterceptor() decorator accepts dynamicPath property as a second argument option. Pass the string path as shown below:

@Post('upload')
@UseInterceptors(
  AmazonS3FileInterceptor('file', {
    dynamicPath: 'aec16138-a75a-4961-b8c1-8e803b6bf2cf'
  }),
)
uploadFile(@UploadedFile() file) {
  console.log(file);
}

In this example, uploadFile() method will upload a file in ${basePath}/aec16138-a75a-4961-b8c1-8e803b6bf2cf/${originalname}.

You may want to store the file with an arbitrary name instead of the original file name. You can do this by passing the randomFilename property attribute set to true as follows:

@Post('upload')
@UseInterceptors(
  AmazonS3FileInterceptor('file', {
    randomFilename: true
  }),
)
uploadFile(@UploadedFile() file) {
  console.log(file);
}

If you want to resize the file before the upload, you can pass on the resize property as follows:

@Post('upload')
@UseInterceptors(
  AmazonS3FileInterceptor('file', {
    resize: { width: 500, height: 400 },
  }),
)
uploadFile(@UploadedFile() file) {
  console.log(file);
}

You can pass an array of size options to resize a single image into different sizes as follows:

@Post('upload')
@UseInterceptors(
  AmazonS3FileInterceptor('file', {
    resizeMultiple: [
      { suffix: 'sm', width: 200, height: 200 },
      { suffix: 'md', width: 300, height: 300 },
      { suffix: 'lg', width: 400, height: 400 },
    ],
  }
)
uploadFile(@UploadedFile() file) {
  console.log(file);
}

Not only creating a thumbnail image but also willing to change the file size limit, you can pass the properties as follows:

@Post('upload')
@UseInterceptors(
    AmazonS3FileInterceptor('file', {
      thumbnail: { suffix: 'thumb', width: 200, height: 200 },
      limits: { fileSize: 7 * 1024 * 1024 },
    }),
  )
uploadFile(@UploadedFile() file) {
  console.log(file);
}

In this example, uploadFile() method will upload both thumbnail and original images.

MulterExtendedS3Options

MulterExtendedModule requires an object with the following interface:

interface MulterExtendedS3Options {
  /**
   * AWS Access Key ID
   */
  readonly accessKeyId: string;
  /**
   * AWS Secret Access Key
   */
  readonly secretAccessKey: string;
  /**
   * Default region name
   * default: us-west-2
   */
  readonly region: string;
  /**
   * The name of Amazon S3 bucket
   */
  readonly bucket: string;
  /**
   * The base path where you want to store files in
   */
  readonly basePath: string;
  /**
   * Optional parameter for Access control level for the file
   * default: public-read
   * @see https://docs.aws.amazon.com/AmazonS3/latest/dev/acl-overview.html#canned-acl
   */
  readonly acl?: string;
  /**
   * Optional parameter for the file size
   * default: 3MB
   */
  readonly fileSize?: number | string;
  /**
   * Optional parameter for a custom logger
   * default: NestJS built-in text-based logger
   * @see https://docs.nestjs.com/techniques/logger
   */
  readonly logger?: LoggerService;
}

MulterExtendedOptions

Key	Default	Description	Example
`dynamicPath`	undefined	The name that you assign to an S3 object	"aec16138-a75a-4961-b8c1-8e803b6bf2cf/random/dir"
`fileFilter`	Accepts JPEG, PNG types only	Function to control which files are accepted
`limits`	3MB	Limits of the uploaded data	5242880 (in bytes)
`resize`	undefined	Resize a single file	{ width: 300, height: 350 }
`resizeMultiple`	undefined	Resize a single file into different sizes (`Array<object>`)	[{ suffix: 'md', width: 300, height: 350 }, { suffix: 'sm', width: 200, height: 200 }]
`thumbnail`	undefined	Create a thumbnail image (`object`)	{ suffix: 'thumbnail', width: 200, height: 200 }