Add AWS S3 storage option

Author: Hein

demos/react-native-supabase-todolist/.env

@@ -1,6 +1,11 @@
 # Replace the credentials below with your Supabase, PowerSync and Expo project details.
 EXPO_PUBLIC_SUPABASE_URL=https://foo.supabase.co
 EXPO_PUBLIC_SUPABASE_ANON_KEY=foo
+EXPO_PUBLIC_ATTACHMENT_STORAGE_OPTION=supabase # Change this to s3 to use AWS S3 storage for attachments
 EXPO_PUBLIC_SUPABASE_BUCKET= # Optional. Only required when syncing attachments and using Supabase Storage. See packages/powersync-attachments.
 EXPO_PUBLIC_POWERSYNC_URL=https://foo.powersync.journeyapps.com
 EXPO_PUBLIC_EAS_PROJECT_ID=foo # Optional. Only required when using EAS.
+EXPO_PUBLIC_AWS_S3_REGION=region
+EXPO_PUBLIC_AWS_S3_BUCKET_NAME=bucket_name
+EXPO_PUBLIC_AWS_S3_ACCESS_KEY_ID=***
+EXPO_PUBLIC_AWS_S3_ACCESS_SECRET_ACCESS_KEY=***

demos/react-native-supabase-todolist/README.md

@@ -2,7 +2,9 @@
 
 ## Overview
 
-Demo app demonstrating use of the [PowerSync SDK for React Native](https://www.npmjs.com/package/@powersync/react-native) together with Supabase.
+Demo app demonstrating the use of the [PowerSync SDK for React Native](https://www.npmjs.com/package/@powersync/react-native) together with Supabase for authentication and two attachment storage options:
+- Supabase (*default*), or
+- [Amazon S3](https://docs.aws.amazon.com/s3/)
 
 A step-by-step guide on Supabase<>PowerSync integration is available [here](https://docs.powersync.com/integration-guides/supabase).
 Follow all the steps until, but not including, [Test Everything (Using Our Demo App)](https://docs.powersync.com/integration-guides/supabase-+-powersync#test-everything-using-our-demo-app).
@@ -30,6 +32,41 @@ cp .env .env.local
 
 And then edit `.env.local` to insert your credentials for Supabase.
 
+## Attachment storage options
+
+To configure attachment storage, you can choose between Supabase and AWS S3. 
+In the `.env.local` file, set `EXPO_PUBLIC_ATTACHMENT_STORAGE_OPTION` to either `supabase` or `s3` to configure the attachment storage option.
+
+### AWS S3 Setup
+
+> **_NOTE:_** This guide assumes that you have an AWS account.
+
+To enable attachment storage using AWS S3, set up an S3 bucket by following these steps:
+#### Create an S3 Bucket:
+
+- Go to the [S3 Console](https://s3.console.aws.amazon.com/s3) and click `Create bucket`.
+- Enter a unique bucket name and select your preferred region.
+- Under Object Ownership, set ACLs disabled and ensure the bucket is private.
+- Enable Bucket Versioning if you need to track changes to files (optional).
+
+#### Configure Permissions:
+
+Go to the Permissions tab and set up the following:
+- A **bucket policy** for access control:
+    - Click Bucket policy and enter a policy allowing the necessary actions
+      (e.g., s3:PutObject, s3:GetObject) for the specific users or roles.
+- _**(Optional)**_ Configure CORS (Cross-Origin Resource Sharing) if your app requires it
+
+#### Create IAM User for Access
+
+- Go to the [IAM Console](https://console.aws.amazon.com/iam) and create a new user with programmatic access.
+- Attach an AmazonS3FullAccess policy to this user, or create a custom policy with specific permissions for the bucket.
+- Save the Access Key ID and Secret Access Key.
+
+In your `.env.local` file, add your AWS credentials and S3 bucket name.
+
+## Run app
+
 Run on iOS
 
 ```sh

demos/react-native-supabase-todolist/library/powersync/system.ts

@@ -2,29 +2,32 @@ import '@azure/core-asynciterator-polyfill';
 
 import { PowerSyncDatabase } from '@powersync/react-native';
 import React from 'react';
-import { SupabaseStorageAdapter } from '../storage/SupabaseStorageAdapter';
-
-import { type AttachmentRecord } from '@powersync/attachments';
+import S3 from 'aws-sdk/clients/s3';
+import { type AttachmentRecord, StorageAdapter } from '@powersync/attachments';
 import Logger from 'js-logger';
 import { KVStorage } from '../storage/KVStorage';
 import { AppConfig } from '../supabase/AppConfig';
 import { SupabaseConnector } from '../supabase/SupabaseConnector';
 import { AppSchema } from './AppSchema';
 import { PhotoAttachmentQueue } from './PhotoAttachmentQueue';
+import { createClient } from '@supabase/supabase-js';
+import { SupabaseStorageAdapter } from '../storage/SupabaseStorageAdapter';
+import { AWSConfig } from '../storage/AWSConfig';
+import { AWSStorageAdapter } from '../storage/AWSStorageAdapter';
 
 Logger.useDefaults();
 
 export class System {
   kvStorage: KVStorage;
-  storage: SupabaseStorageAdapter;
+  storage: StorageAdapter;
   supabaseConnector: SupabaseConnector;
   powersync: PowerSyncDatabase;
   attachmentQueue: PhotoAttachmentQueue | undefined = undefined;
 
   constructor() {
     this.kvStorage = new KVStorage();
     this.supabaseConnector = new SupabaseConnector(this);
-    this.storage = this.supabaseConnector.storage;
+    this.storage = getStorageAdapter(this);
     this.powersync = new PowerSyncDatabase({
       schema: AppSchema,
       database: {
@@ -44,7 +47,7 @@ export class System {
      * this.powersync = new PowerSyncDatabase({ database: factory, schema: AppSchema });
      */
 
-    if (AppConfig.supabaseBucket) {
+    if (AppConfig.supabaseBucket || AppConfig.s3bucketName) {
       this.attachmentQueue = new PhotoAttachmentQueue({
         powersync: this.powersync,
         storage: this.storage,
@@ -71,6 +74,31 @@ export class System {
   }
 }
 
+function getStorageAdapter(system: System): StorageAdapter {
+  const storageProvider = AppConfig.storageOption;
+
+  if (storageProvider === 'supabase') {
+    const client = createClient(AppConfig.supabaseUrl, AppConfig.supabaseAnonKey, {
+      auth: {
+        persistSession: true,
+        storage: system.kvStorage
+      }
+    });
+    return new SupabaseStorageAdapter({ client: client });
+  } else if (storageProvider === 's3') {
+    const s3Client = new S3({
+      region: AWSConfig.region,
+      credentials: {
+        accessKeyId: AWSConfig.accessKeyId,
+        secretAccessKey: AWSConfig.secretAccessKey
+      }
+    });
+    return new AWSStorageAdapter({ client: s3Client });
+  } else {
+    throw new Error('Invalid storage provider specified in STORAGE_PROVIDER');
+  }
+}
+
 export const system = new System();
 
 export const SystemContext = React.createContext(system);

demos/react-native-supabase-todolist/library/storage/AWSConfig.ts

@@ -0,0 +1,6 @@
+export const AWSConfig = {
+  region: process.env.EXPO_PUBLIC_AWS_S3_REGION,
+  accessKeyId: process.env.EXPO_PUBLIC_AWS_S3_ACCESS_KEY_ID || '',
+  secretAccessKey: process.env.EXPO_PUBLIC_AWS_S3_ACCESS_SECRET_ACCESS_KEY || '',
+  bucketName: process.env.EXPO_PUBLIC_AWS_S3_BUCKET_NAME || ''
+};

demos/react-native-supabase-todolist/library/storage/AWSStorageAdapter.ts

@@ -0,0 +1,94 @@
+import * as FileSystem from 'expo-file-system';
+import { AWSConfig } from './AWSConfig';
+import S3 from 'aws-sdk/clients/s3';
+import { BaseStorageAdapter } from './BaseStorageAdapter';
+
+export interface S3StorageAdapterOptions {
+  client: S3;
+}
+
+export class AWSStorageAdapter extends BaseStorageAdapter {
+  constructor(private options: S3StorageAdapterOptions) {
+    super();
+  }
+
+  async uploadFile(
+    filename: string,
+    data: ArrayBuffer,
+    options?: {
+      mediaType?: string;
+    }
+  ): Promise<void> {
+    if (!AWSConfig.bucketName) {
+      throw new Error('AWS S3 bucket not configured in AppConfig.ts');
+    }
+
+    try {
+      const body = Uint8Array.from(new Uint8Array(data));
+      const params = {
+        Bucket: AWSConfig.bucketName,
+        Key: filename,
+        Body: body,
+        ContentType: options?.mediaType
+      };
+
+      await this.options.client.upload(params).promise();
+      console.log(`File uploaded successfully to ${AWSConfig.bucketName}/${filename}`);
+    } catch (error) {
+      console.error('Error uploading file:', error);
+      throw error;
+    }
+  }
+
+  async downloadFile(filePath: string): Promise<Blob> {
+    const s3 = new S3({
+      region: AWSConfig.region,
+      accessKeyId: AWSConfig.accessKeyId,
+      secretAccessKey: AWSConfig.secretAccessKey
+    });
+
+    const params = {
+      Bucket: AWSConfig.bucketName,
+      Key: filePath
+    };
+
+    try {
+      const obj = await s3.getObject(params).promise();
+      if (obj.Body) {
+        const data = await new Response(obj.Body as ReadableStream).arrayBuffer();
+        return new Blob([data]);
+      } else {
+        throw new Error('Object body is undefined. Could not download file.');
+      }
+    } catch (error) {
+      console.error('Error downloading file:', error);
+      throw error;
+    }
+  }
+
+  async deleteFile(uri: string, options?: { filename?: string }): Promise<void> {
+    if (await this.fileExists(uri)) {
+      await FileSystem.deleteAsync(uri);
+    }
+
+    const { filename } = options ?? {};
+    if (!filename) {
+      return;
+    }
+
+    if (!AWSConfig.bucketName) {
+      throw new Error('Supabase bucket not configured in AppConfig.ts');
+    }
+
+    try {
+      const params = {
+        Bucket: AWSConfig.bucketName,
+        Key: filename
+      };
+      await this.options.client.deleteObject(params).promise();
+      console.log(`${filename} deleted successfully from ${AWSConfig.bucketName}.`);
+    } catch (error) {
+      console.error(`Error deleting ${filename} from ${AWSConfig.bucketName}:`, error);
+    }
+  }
+}

demos/react-native-supabase-todolist/library/storage/BaseStorageAdapter.ts

@@ -0,0 +1,68 @@
+import { StorageAdapter } from '@powersync/attachments';
+import * as FileSystem from 'expo-file-system';
+import { decode as decodeBase64 } from 'base64-arraybuffer';
+
+export abstract class BaseStorageAdapter implements StorageAdapter {
+  async readFile(
+    fileURI: string,
+    options?: { encoding?: FileSystem.EncodingType; mediaType?: string }
+  ): Promise<ArrayBuffer> {
+    const { encoding = FileSystem.EncodingType.UTF8 } = options ?? {};
+    const { exists } = await FileSystem.getInfoAsync(fileURI);
+    if (!exists) {
+      throw new Error(`File does not exist: ${fileURI}`);
+    }
+    const fileContent = await FileSystem.readAsStringAsync(fileURI, options);
+    if (encoding === FileSystem.EncodingType.Base64) {
+      return this.base64ToArrayBuffer(fileContent);
+    }
+    return this.stringToArrayBuffer(fileContent);
+  }
+
+  async writeFile(
+    fileURI: string,
+    base64Data: string,
+    options?: {
+      encoding?: FileSystem.EncodingType;
+    }
+  ): Promise<void> {
+    const { encoding = FileSystem.EncodingType.UTF8 } = options ?? {};
+    await FileSystem.writeAsStringAsync(fileURI, base64Data, { encoding });
+  }
+
+  async fileExists(fileURI: string): Promise<boolean> {
+    const { exists } = await FileSystem.getInfoAsync(fileURI);
+    return exists;
+  }
+
+  async makeDir(uri: string): Promise<void> {
+    const { exists } = await FileSystem.getInfoAsync(uri);
+    if (!exists) {
+      await FileSystem.makeDirectoryAsync(uri, { intermediates: true });
+    }
+  }
+
+  async copyFile(sourceUri: string, targetUri: string): Promise<void> {
+    await FileSystem.copyAsync({ from: sourceUri, to: targetUri });
+  }
+
+  getUserStorageDirectory(): string {
+    return FileSystem.documentDirectory!;
+  }
+
+  async stringToArrayBuffer(str: string): Promise<ArrayBuffer> {
+    const encoder = new TextEncoder();
+    return encoder.encode(str).buffer;
+  }
+
+  /**
+   * Converts a base64 string to an ArrayBuffer
+   */
+  async base64ToArrayBuffer(base64: string): Promise<ArrayBuffer> {
+    return decodeBase64(base64);
+  }
+
+  abstract uploadFile(filePath: string, data: ArrayBuffer, options?: { mediaType?: string }): Promise<void>;
+  abstract downloadFile(filePath: string): Promise<Blob>;
+  abstract deleteFile(uri: string, options?: { filename?: string }): Promise<void>;
+}

demos/react-native-supabase-todolist/library/storage/SupabaseStorageAdapter.ts

@@ -1,15 +1,16 @@
 import { SupabaseClient } from '@supabase/supabase-js';
-import { decode as decodeBase64 } from 'base64-arraybuffer';
 import * as FileSystem from 'expo-file-system';
 import { AppConfig } from '../supabase/AppConfig';
-import { StorageAdapter } from '@powersync/attachments';
+import { BaseStorageAdapter } from './BaseStorageAdapter';
 
 export interface SupabaseStorageAdapterOptions {
   client: SupabaseClient;
 }
 
-export class SupabaseStorageAdapter implements StorageAdapter {
-  constructor(private options: SupabaseStorageAdapterOptions) {}
+export class SupabaseStorageAdapter extends BaseStorageAdapter {
+  constructor(private options: SupabaseStorageAdapterOptions) {
+    super();
+  }
 
   async uploadFile(
     filename: string,
@@ -55,21 +56,6 @@ export class SupabaseStorageAdapter implements StorageAdapter {
     const { encoding = FileSystem.EncodingType.UTF8 } = options ?? {};
     await FileSystem.writeAsStringAsync(fileURI, base64Data, { encoding });
   }
-  async readFile(
-    fileURI: string,
-    options?: { encoding?: FileSystem.EncodingType; mediaType?: string }
-  ): Promise<ArrayBuffer> {
-    const { encoding = FileSystem.EncodingType.UTF8 } = options ?? {};
-    const { exists } = await FileSystem.getInfoAsync(fileURI);
-    if (!exists) {
-      throw new Error(`File does not exist: ${fileURI}`);
-    }
-    const fileContent = await FileSystem.readAsStringAsync(fileURI, options);
-    if (encoding === FileSystem.EncodingType.Base64) {
-      return this.base64ToArrayBuffer(fileContent);
-    }
-    return this.stringToArrayBuffer(fileContent);
-  }
 
   async deleteFile(uri: string, options?: { filename?: string }): Promise<void> {
     if (await this.fileExists(uri)) {
@@ -93,36 +79,4 @@ export class SupabaseStorageAdapter implements StorageAdapter {
 
     console.debug('Deleted file from storage', data);
   }
-
-  async fileExists(fileURI: string): Promise<boolean> {
-    const { exists } = await FileSystem.getInfoAsync(fileURI);
-    return exists;
-  }
-
-  async makeDir(uri: string): Promise<void> {
-    const { exists } = await FileSystem.getInfoAsync(uri);
-    if (!exists) {
-      await FileSystem.makeDirectoryAsync(uri, { intermediates: true });
-    }
-  }
-
-  async copyFile(sourceUri: string, targetUri: string): Promise<void> {
-    await FileSystem.copyAsync({ from: sourceUri, to: targetUri });
-  }
-
-  getUserStorageDirectory(): string {
-    return FileSystem.documentDirectory!;
-  }
-
-  async stringToArrayBuffer(str: string): Promise<ArrayBuffer> {
-    const encoder = new TextEncoder();
-    return encoder.encode(str).buffer;
-  }
-
-  /**
-   * Converts a base64 string to an ArrayBuffer
-   */
-  async base64ToArrayBuffer(base64: string): Promise<ArrayBuffer> {
-    return decodeBase64(base64);
-  }
 }