Remove aws-sdk dependency from AWS Lambda node

packages/nodes-base/nodes/Aws/GenericFunctions.ts

@@ -6,7 +6,7 @@ import {
 
 import { config } from 'aws-sdk';
 import { OptionsWithUri } from 'request';
-
+import { sign } from 'aws4';
 
 export async function awsConfigCredentials(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions): Promise<void> {
 	const credentials = this.getCredentials('aws');
@@ -21,3 +21,48 @@ export async function awsConfigCredentials(this: IHookFunctions | IExecuteFuncti
 		secretAccessKey: `${credentials.secretAccessKey}`,
 	});
 }
+
+export async function awsApiRequest(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions, service: string, method: string, path: string, body?: string, headers?: object): Promise<any> { // tslint:disable-line:no-any
+	const credentials = this.getCredentials('aws');
+
+	if (credentials === undefined) {
+		throw new Error('No credentials got returned!');
+	}
+
+	const endpoint = `${service}.${credentials.region}.amazonaws.com`
+
+	// Sign AWS API request with the user credentials
+	const signOpts = {headers: headers || {}, host: endpoint, method: method, path: path, body: body}
+	sign(signOpts, {accessKeyId: `${credentials.accessKeyId}`, secretAccessKey: `${credentials.secretAccessKey}`})
+
+	const options: OptionsWithUri = {
+		headers: signOpts.headers,
+		method: method,
+		uri: `https://${endpoint}${signOpts.path}`,
+		body: signOpts.body,
+	};
+
+	let response: string
+	try {
+		response = await this.helpers.request!(options);
+	} catch (error) {
+		console.error(error);
+
+		const errorMessage = error.response.body.message || error.response.body.Message;
+		if (error.statusCode === 403) {
+			if (errorMessage == 'The security token included in the request is invalid.') {
+				throw new Error('The AWS credentials are not valid!');
+			} else if (errorMessage.startsWith('The request signature we calculated does not match the signature you provided')) {
+				throw new Error('The AWS credentials are not valid!');
+			}
+		}
+
+		throw errorMessage;
+	}
+
+	try {
+		return JSON.parse(response);
+	} catch (e) {
+		return response
+	}
+}