pip-services-changescopes-node

Change Scopes Microservice

This is a change scope microservice from Pip.Services library. It detects changes made in a particular scope or element of a scope.

This microservice is intended to implement change detection using simple pull mechanism. For instance: multiple configuration microservices change the scope, and business logic that depends on those configurations periodically reads it to check if anything was changed.

The microservice currently supports the following deployment options:

• Deployment platforms: Standalone Process, Seneca
• External APIs: HTTP/REST, Seneca
• Persistence: Flat Files, MongoDB

This microservice has no dependencies on other microservices.

Quick Links:

• Download Links
• Development Guide
• Configuration Guide
• Deployment Guide
• Client SDKs
  • Node.js SDK
• Communication Protocols
  • HTTP Version 1
  • Seneca Version 1

Contract

Logical contract of the microservice is presented below. For physical implementation (HTTP/REST, Thrift, Seneca, Lambda, etc.), please, refer to documentation of the specific protocol.

class ChangeScopeV1 implements IStringIdentifiable {
    public id: string;
    public change_time: Date;
    public elements: { [element: string]: Date };
}
 
interface IChangeScopesV1 {
    getScopeById(correlationId: string, id: string, 
        callback: (err: any, scope: ChangeScopeV1) => void): void;
 
    changeScope(correlationId: string, id: string,
        callback?: (err: any, scope: ChangeScopeV1) => void): void;
 
    changeScopeElement(correlationId: string, id: string, element: string,
        callback?: (err: any, scope: ChangeScopeV1) => void): void;
 
    deleteScopeById(correlationId: string, id: string, 
        callback?: (err: any, scope: ChangeScopeV1) => void): void;
}

Download

Right now the only way to get the microservice is to check it out directly from github repository

git clone [e-mail]:pip-services-infrastructure/pip-services-changescopes-node.git

Pip.Service team is working to implement packaging and make stable releases available for your as zip downloadable archieves.

Run

Add config.yml file to the root of the microservice folder and set configuration parameters. As the starting point you can use example configuration from config.example.yml file.

Example of microservice configuration

- descriptor: "pip-services-container:container-info:default:default:1.0"
  name: "pip-services-changescopes"
  description: "ChangeScopes microservice"
 
- descriptor: "pip-services-commons:logger:console:default:1.0"
  level: "trace"
 
- descriptor: "pip-services-changescopes:persistence:file:default:1.0"
  path: "./data/settings.json"
 
- descriptor: "pip-services-changescopes:controller:default:default:1.0"
 
- descriptor: "pip-services-changescopes:service:http:default:1.0"
  connection:
    protocol: "http"
    host: "0.0.0.0"
    port: 8080

For more information on the microservice configuration see Configuration Guide.

Start the microservice using the command:

node run

Use

The easiest way to work with the microservice is to use client SDK. The complete list of available client SDKs for different languages is listed in the Quick Links

If you use Node.js then you should add dependency to the client SDK into package.json file of your project

{
    ...
    "dependencies": {
        ....
        "pip-clients-changescopes-node": "^1.0.*",
        ...
    }
}

Inside your code get the reference to the client SDK

var sdk = new require('pip-clients-changescopes-node');

Define client configuration parameters that match configuration of the microservice external API

// Client configuration
var config = {
    connection: {
        protocol: 'http',
        host: 'localhost', 
        port: 8080
    }
};

Instantiate the client and open connection to the microservice

// Create the client instance
var client = sdk.ChangeScopesHttpClientV1(config);
 
// Connect to the microservice
client.open(null, function(err) {
    if (err) {
        console.error('Connection to the microservice failed');
        console.error(err);
        return;
    }
    
    // Work with the microservice
    ...
});

Now the client is ready to perform operations

 
// Changes scope
client.changeScope(
    null,
    '123',
    parameters,
    function (err, scope) {
        ...
    }
);

// Get change scopes
client.getScopeById(
    null,
    '123',
    function(err, scope) {
    ...    
    }
);

Acknowledgements

This microservice was created and currently maintained by Sergey Seroukhov.