middleware-service-sdk

Middleware service for which expose rest api

Installation

This module is a part of middleware services. It's library and use it only through node_modules Write in package.json:

  "dependencies": {
    "middleware_service.sdk": "github:chronobank/middleware-service-sdk"

then

npm i

About

This module works on the basis of Node-Red. As is known, Node-red is a programming tool for wiring together hardware devices, APIs and online services. Middleware-service-sdk extends the standard sets of components of Node-red such as.

New components

type of node	name of node	description
input	amqp	AMQP input node. Connects to a server and subscribes to the specified exchange or queue
output	amqp	AMQP output node. Connects to a server and delivers the message payload to the specified exchange or queue
function	async function	A JavaScript function block to run against the messages being received by th node
connectors	mongo	single mongoose query connector
utils	query to mongo	converts query params to mongo like query

How it work

This module uses mongoDB as a database. Module creates 3 collections: migrations, noderedstorage and nodereduser.

Collection 'migrations' keeps id flows which was subjected to migration. Collection 'noderedstorages' keeps all created flows. Collection 'noderedusers' keeps information about an admin.

In order to start a service we tentatively need to add an admin`s record to the noderedusers collection. And after that we can start to work.

After deploying your flow it will save in your project, by default it is a folder 'migration'. Also it saves in a database in the noderedstoreges collection.

After service restart, he will upload earlier created flows.

In the event if you need to import your flows in the another database, there is a migration tool in the service-sdk.

Example

Let`s make simple API where we can register our new wallet addresses.

Step by step:

1. add 'http end-point' component - it is our request and name it 'create addr'

2. add service-sdk - 'amqp in' component to be connected to the rabbitmq queue/exchange, named it 'post addresses'

3. add 'function' component for the 'amqp in'

4. add 'function' component that will allow us to process the request to add new addresses

5. add service-sdk - 'mongo' component that will save our new record in the mongoDB

6. add 'switch' component that will route messages for respond and event in rabbitmq

7. add 'function' component that will forms the answer for responce

8. add 'function' component that will forms event in rabbitmq

9. Finally, add the 'http responce' and 'amqp out' components, where 'http responce' send responce and 'amqp out' send event to rabbitmq

10. We can deploy our flow

сonfigure this module

To apply your configuration, send this variables to redInitter in config.nodered

const config = require('config');
const redInitter = require('middleware_service.sdk').init;
const migrator = require('middleware_service.sdk').migrator;

 if (config.nodered.autoSyncMigrations)
   await migrator.run(config.nodered.mongo.uri, path.join(__dirname, 'migrations'));

 redInitter(config);

What variables you need save in config.nodered

path	type	description
mongo.uri	String	url for connection to mongo, where save migrations, users and flows
mongo.collectionPrefix	String	prefix to collection in mongo, where save migrations, users and flows
autoSyncMigrations	Boolean	auto synchronization migrations in storage or not
customNodesDir	[String]	Array with paths to dir with nodes, that use in this sdk
migrationsInOneFile	Boolean	save migrations and update in one file for one flow, or save update migrations in different files
useLocalStorage	Boolean	use mongo or local file to save migrations, nodes, and users
functionGlobalContext	Object	context with variables, that shares to your functions in nodered

Below is the expamle configuration:

    mongo: {
      uri: process.env.NODERED_MONGO_URI || process.env.MONGO_URI || 'mongodb://localhost:27017/data',
      collectionPrefix: process.env.NODE_RED_MONGO_COLLECTION_PREFIX || '',
    },
    autoSyncMigrations: process.env.NODERED_AUTO_SYNC_MIGRATIONS || true,
    customNodesDir: [path.join(__dirname, '../')],
    migrationsInOneFile: false,
    useLocalStorage: false,
    
    migrationsDir: path.join(__dirname, '../migrations'),
    functionGlobalContext: {
      factories: {
        sm: require('../factories/sc/smartContractsFactory')
      },
      'truffle-contract': require('truffle-contract'),
      connections: {
        primary: mongoose
      },
      settings: {
        mongo: {
          accountPrefix: process.env.MONGO_ACCOUNTS_COLLECTION_PREFIX || process.env.MONGO_COLLECTION_PREFIX || 'eth',
          collectionPrefix: process.env.MONGO_DATA_COLLECTION_PREFIX || process.env.MONGO_COLLECTION_PREFIX || 'eth'
        },
        rabbit: {
          url: process.env.RABBIT_URI || 'amqp://localhost:5672',
          serviceName: process.env.RABBIT_SERVICE_NAME || 'app_eth'
        }
      }
    }

License

GNU AGPLv3

Copyright

LaborX PTY