eip-cloud-services/README.md

Houses a collection of helpers for connecting with Cloud services.

# EIP Cloud Services Module

## Summary

The EIP Cloud Services Module is a comprehensive Node.js package that provides seamless integration with various cloud services, including Redis, AWS S3, CDN, AWS Lambda, and MySQL. This module is designed to simplify the complexities of interacting with these cloud services, offering a range of functionalities from data caching and storage to content delivery and serverless computing.

## Installation and Import

To use this module, first install it in your Node.js project. Then, import the required services as follows:

```javascript
const { redis, cdn, mysql } = require('eip-cloud-services');
```

## Config Example

Here is an example configuration for the EIP Cloud Services Module. Replace the placeholder values with your actual configuration details.

```javascript
const packageJson = require('../package.json');

module.exports = {
    cdn: {
        ['cdnName']: { // e.g. "myCdn"
            ['envName1']: { //e.g. "production"
                type: 'google',
                urlMapName: 'YOUR_GCP_URL_MAP_NAME',
                projectId: 'YOUR_GCP_PROJECT_NAME',
            },
            ['envName2']: { // e.g. "staging"
                type: 'amazon',
                distributionId: 'YOUR_DISTRIBUTION_ID',
            }
        },
    },
    redis: { // For regular redis connections
        port: 'YOUR_REDIS_PORT',
        host: 'YOUR_REDIS_HOST',
        prefix: 'YOUR_REDIS_PREFIX',
    },
    redis: { // For redis cluster instances
        prefix: 'YOUR_REDIS_PREFIX',
        clusterEnabled: true,
        cluster: [
            {
                port: 'YOUR_REDIS_PORT',
                host: 'YOUR_REDIS_HOST',
            },
            {
                port: 'YOUR_REDIS_PORT_2',
                host: 'YOUR_REDIS_HOST_2',
            },
            ...
        ]
    },
    s3: {
        Bucket: 'YOUR_S3_BUCKET',
        logs: "verbose", // "verbose" or "outputs", any other value will not log. verbose will log all activity. outputs will only log when there is a file updated.
        logsFunction: ( message ) => { ... } // Optional, if nothing is provided console.log will be used.
    },
    mysql: {
        connectionLimit: 10, // Max connections
        host: 'my-database.domain.com',
        user: 'user',
        password: 'password',
        database: 'my-database', // defaults to undefined
        multipleStatements: false // defaults to true if not set
    }
};
```

## Table of Contents

1. [Redis Module](#redis-module)
2. [AWS S3 Module](#aws-s3-module)
3. [CDN Module](#cdn-module)
4. [MySQL Module](#mysql-module)
5. [AWS Lambda Module](#aws-lambda-module)

# AWS Lambda Module

## Overview

This module provides an interface for invoking AWS Lambda functions. It simplifies the process of triggering Lambda functions from your Node.js application, with support for both synchronous and asynchronous invocations.

## Installation

Ensure this module is included in your Node.js project. Import the Lambda component as follows:

```javascript
const lambda = require('eip-cloud-services/lambda');
```

## Usage

### Invoking a Lambda Function

You can invoke a Lambda function by specifying the function name and the event payload. The module supports both waiting for the function execution to complete and fire-and-forget invocations.

#### Synchronous Invocation (Wait for Execution to start)

```javascript
const response = await lambda.invokeLambda('yourFunctionName', { key: 'value' }, true);
console.log(response);
```

#### Asynchronous Invocation (Fire-and-Forget)

```javascript
await lambda.invokeLambda('yourFunctionName', { key: 'value' }, false);
```

### Parameters

- `functionName`: The name of the Lambda function to invoke.
- `eventPayload`: The payload to pass to the function. This can be any valid JSON object.
- `waitForExecution` (optional): Set to `true` to wait for the execution to start and receive a response.
- `context` (optional): The client context for the function execution.
- `invocationType` (optional): Defaults to 'Event'. Can be set to 'RequestResponse' for synchronous execution.
- `logType` (optional): The type of logging for the function.

## Configuration

Configure the module with your AWS credentials and Lambda settings.

## Error Handling

The module includes error handling to manage issues related to Lambda invocation, such as network errors or configuration problems.

## Logging

Logging is provided to track the start and completion of Lambda invocations, aiding in debugging and monitoring.

# MySQL Module

## Overview

This MySQL module provides a simple and efficient interface for interacting with MySQL databases. It includes functionalities to manage database connections, execute queries, and handle connection pooling.

## Installation

Ensure this module is included in your Node.js project. Import the MySQL component as follows:

```javascript
const mysql = require('eip-cloud-services/mysql');
```

## Usage

### Executing Queries

You can execute queries using the `query` method. This method automatically handles connections and releases them after query execution.

```javascript
const results = await mysql.query('SELECT * FROM your_table');
console.log(results);
```

### Manually Managing Database Connections

It's not required for you to get connections manually, you can use the methods directly without having to setup connections. Getting a connection should only be used if you need to parse the connection to a third party module for example.

#### Get a Connection Pool

```javascript
const pool = mysql.getPool();
```

#### Get a Single Connection

```javascript
const connection = await mysql.getConnection();
```


### Closing the Connection Pool

To gracefully close all connections in the pool:

```javascript
await mysql.kill();
```

## Configuration

Configure your MySQL connection settings (like host, user, password, etc.) in the `config` directory.

## Error Handling

The module is designed to handle errors gracefully, providing clear error messages for database connection issues and query errors.

## Pooling

- The module uses connection pooling for efficient database interaction.
- The pool is automatically created and managed by the module.


# CDN Module

## Overview

This module provides functionalities to manage and interact with Content Delivery Networks (CDNs) like Amazon CloudFront and Google Cloud CDN. It includes features for creating invalidations, thereby ensuring that the latest content is served to end-users.

## Installation

Ensure this module is included in your Node.js project. Import the CDN component as follows:

```javascript
const cdn = require('eip-cloud-services/cdn');
```

## Usage

### Create a CDN Invalidation

To invalidate cached content in a CDN, use the `createInvalidation` method. This method supports invalidating content in both Amazon CloudFront and Google Cloud CDN.

#### Invalidate in Amazon CloudFront

```javascript
await cdn.createInvalidation('amazon', 'path/to/your/file.jpg', 'production');
```

#### Invalidate in Google Cloud CDN

```javascript
await cdn.createInvalidation('google', 'path/to/your/file.jpg', 'production');
```

You can also invalidate multiple paths by passing an array of keys:

```javascript
await cdn.createInvalidation('amazon', ['file1.jpg', 'file2.jpg'], 'staging');
```

## Configuration

Configure the module with your CDN settings in the `config` directory. The configuration should include details like project ID, distribution ID, and URL map names for the respective CDNs.

## Error Handling

The module is equipped to handle errors gracefully, including validation of input parameters and handling CDN-specific errors.

## Advanced Features

- Supports both Amazon CloudFront and Google Cloud CDN.
- Validates the key argument to ensure proper formatting.
- Constructs invalidation paths based on the provided keys.
- Initializes Google Auth if Google CDN is used.
- Sends invalidation commands to the CDN client based on the type of CDN and environment.


# AWS S3 Module

## Overview

This module provides an interface for interacting with AWS S3, offering functionalities like object retrieval, storage, deletion, and more. It supports advanced features such as encryption and cache control directives, making it a versatile tool for managing S3 operations efficiently.

## Installation

Ensure this module is included in your Node.js project. Import the S3 component as follows:

```javascript
const s3 = require('eip-cloud-services/s3');
```

## Usage

### Check if an Object Exists

```javascript
const exists = await s3.exists('myObjectKey');
console.log(exists); // true if exists, false otherwise
```

### Retrieve an Object

```javascript
const object = await s3.get('myObjectKey');
console.log(object);
```

### Store an Object

```javascript
await s3.set('myObjectKey', 'myObjectData', { /* options */ });
```

### Delete an Object

```javascript
await s3.del('myObjectKey');
```

### Copy an Object

```javascript
await s3.copy('sourceObjectKey', 'destinationObjectKey');
```

### Move an Object

```javascript
await s3.move('sourceObjectKey', 'destinationObjectKey');
```

### Managing Cache-Control and Encryption

The module provides detailed control over cache behavior and supports encryption for stored objects, allowing you to optimize performance and security.

## Configuration

Configure the module with your AWS credentials and preferred settings in the `config` directory.

## Error Handling

The module includes comprehensive error handling, ensuring robust interaction with AWS S3 even in complex scenarios.



# Redis Module

## Overview

This Redis module provides a robust interface for interacting with Redis, supporting both standard Redis operations and advanced features like Redis Clusters. The module is designed to manage multiple Redis client instances efficiently, allowing seamless operation with different Redis configurations.

## Installation

To use this Redis module, first ensure that it is included in your Node.js project. You can import the module as follows:

```javascript
const redis = require('eip-cloud-services/redis');
```

## Usage

### Standard Redis Operations

You can perform standard Redis operations like setting, getting, deleting keys, etc. Here are some examples:

#### Set a Key

```javascript
await redis.set('myKey', 'myValue');
```

#### Get a Key

```javascript
const value = await redis.get('myKey');
console.log(value); // Outputs: myValue
```

#### Delete a Key

```javascript
await redis.del('myKey');
```

### Advanced Operations

#### Using Redis Cluster

If your Redis setup includes a cluster, the module automatically configures the client for cluster operations based on your configuration.

#### Subscribing to a Channel

```javascript
redis.subscribe('myChannel', (message) => {
  console.log(`Received: ${message}`);
});
```

#### Publishing to a Channel

```javascript
await redis.publish('myChannel', 'Hello, World!');
```

### Managing Redis Clients

The module internally manages multiple Redis clients for different purposes (like separate clients for pub/sub). However, this is abstracted away from the standard use of the module.

## Error Handling

The module is designed to gracefully handle Redis errors, including connection issues and cluster errors.