feat(server): add storage adapter for aws dynamodb

Author: Fuss Florian (uid10804)

packages/server/package.json

@@ -10,8 +10,9 @@
   },
   "scripts": {
     "test": "npx jest",
-    "debug": "tsc-watch --onSuccess \"node --inspect-brk ./lib/example/simple.js\"",
-    "start": "tsc-watch --onSuccess \"node ./lib/example/simple.js\"",
+    "debug": "tsc-watch --onSuccess \"node --inspect-brk ./lib/example/simple.s3.js\"",
+    "start": "tsc-watch --onSuccess \"node ./lib/example/simple.s3.js\"",
+    "start:dynamodb": "tsc-watch --onSuccess \"node ./lib/example/simple.dynamodb.js\"",
     "start:advanced": "tsc-watch --onSuccess \"node ./lib/example/advanced.js\"",
     "type-check": "tsc --noEmit",
     "type-check:watch": "npm run type-check -- --watch",

packages/server/src/example/simple.dynamodb.ts

@@ -0,0 +1,50 @@
+import express from 'express';
+import {
+  AppConfig,
+  CoreApp,
+  Environment,
+  PublicStrategy,
+  Swagger,
+  SwaggerConfig,
+} from '../index';
+import { DynamoDBStorageAdapter } from '../storage/dynamodb.storage';
+const server = express();
+const appConfig = new AppConfig();
+
+const environment = new Environment();
+
+const swagger = new Swagger(
+  server,
+  new SwaggerConfig(appConfig.readOnly, appConfig.enableApiKeyAuth),
+  environment.basePath,
+  appConfig.routes.apiRoutePath,
+  './package.json',
+  appConfig.routes.swaggerSpecRoutePath
+);
+
+const core = new CoreApp(
+  appConfig,
+  server,
+  new DynamoDBStorageAdapter(
+    'json-serverless-simple-example1',
+    appConfig.stackName,
+    appConfig.jsonFile,
+    'us-east-1'
+  ),
+  swagger,
+  environment,
+  new PublicStrategy()
+);
+
+const init = async () => {
+  await core!.setup().catch(e => {
+    console.error(e.message);
+  });
+  console.log(
+    'JSON Server is running under port 3000. Use http://localhost:3000/  to access it'
+  );
+
+  server.listen(3000);
+};
+
+init();

packages/server/src/example/simple.ts renamed to packages/server/src/example/simple.s3.ts

@@ -0,0 +1,66 @@
+import { DynamoDB } from 'aws-sdk';
+
+export class DynamoDBLowDBAdapter {
+  dynamo: DynamoDB.DocumentClient;
+  defaultValue: {};
+  table: string;
+  keyId: string;
+  source = '';
+  readonly '@@reference': any;
+  constructor(defaultValue = {}, table: string, keyId: string, region: string) {
+    this.defaultValue = defaultValue;
+    this.dynamo = new DynamoDB.DocumentClient({
+      apiVersion: '2012-08-10',
+      region,
+    });
+    this.table = table;
+    this.keyId = keyId;
+  }
+
+  async read(): Promise<object> {
+    let result = null;
+    try {
+      const params: DynamoDB.DocumentClient.GetItemInput = {
+        TableName: this.table,
+        Key: {
+          keyId: this.keyId,
+        },
+      };
+      console.log(JSON.stringify(params));
+      result = await this.dynamo.get(params).promise();
+    } catch (error) {
+      console.log(error.message);
+      throw error;
+    }
+
+    if (result.Item === undefined || result.Item === null) {
+      this.write(this.defaultValue);
+      return this.defaultValue;
+    }
+    return JSON.parse(result.Item![this.keyId]);
+  }
+
+  async write(data: object) {
+    try {
+      const params: DynamoDB.DocumentClient.PutItemInput = {
+        TableName: this.table,
+        Item: {
+          keyId: this.keyId,
+          jsonsls: JSON.stringify(data),
+        },
+      };
+      await this.dynamo.put(params).promise();
+    } catch (error) {
+      if (
+        error.code === 'ValidationException' &&
+        error.message === 'Item size has exceeded the maximum allowed size'
+      ) {
+        throw new Error(
+          'Item size has exceeded the maximum allowed size (currently 400 kb) - Please use another storage provider e.g. S3 to store large files'
+        );
+      } else {
+        throw new Error(error.message);
+      }
+    }
+  }
+}

packages/server/src/storage/dynamodb.adapter.ts

@@ -0,0 +1,30 @@
+import { StorageAdapter } from './storage';
+import fs from 'fs';
+import { DynamoDBLowDBAdapter } from './dynamodb.adapter';
+import { AdapterAsync } from 'lowdb';
+
+export class DynamoDBStorageAdapter implements StorageAdapter {
+  private table: string;
+  private keyId: string;
+  private jsonFilePath: string;
+  private region: string;
+  constructor(table: string, keyId: string, jsonFilePath: string, region) {
+    this.table = table;
+    this.keyId = keyId;
+    this.jsonFilePath = jsonFilePath;
+    this.region = region;
+  }
+
+  init(): import('lowdb').AdapterAsync {
+    console.log('initController');
+    const db = JSON.parse(fs.readFileSync(this.jsonFilePath, 'UTF-8'));
+    const storageAdapter = new DynamoDBLowDBAdapter(
+      db,
+      this.table,
+      this.keyId,
+      this.region
+    ) as unknown;
+
+    return storageAdapter as AdapterAsync;
+  }
+}

packages/server/src/storage/dynamodb.storage.ts

@@ -1,3 +1,5 @@
 export * from './file.storage';
 export * from './storage';
 export * from './s3.storage';
+export * from './dynamodb.storage';
+export * from './dynamodb.adapter';