corbel-composer

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Overview

CompoSR is a nodeJS middleware, built on top of express, for Corbel.

It offers developers the ability to make their own specific application API based in corbel-js

It is responsible for composing phrases of code than can be reused by multiple applications. This way you can keep your code reusable and simplify your API.

wiki: A composer (Latin com+ponere, literally "one who puts together") is a person who creates music.

wiki: In music and music theory, phrase and phrasing are concepts and practices related to grouping consecutive melodic notes, both in their composition and performance. A musical work is typically made up of a melody that consists of numerous consecutive phrases.

Diagram

QuickStart

• install

  npm install -g bq/corbel-composer
  

• run server

  corbel-composer
  

Postman Playground

1. Get postman
2. Import corbel-composer collection:

https://raw.githubusercontent.com/bq/corbel-composer/master/doc/postman/postman.json

1. Import evironment example:

https://raw.githubusercontent.com/bq/corbel-composer/master/doc/postman/environment.example.json

1. Import globals:

https://raw.githubusercontent.com/bq/corbel-composer/master/doc/postman/globals.example.json

1. Enjoy!

Phrase Model

{
    "url": "phraseName",
    "get": {
        "code": "res.render('index', {title: 'hello world'});",
        "doc": {
            "description": "Phrase description",
            "queryParameters": {
                "param1": {
                    "type": "number",
                    "description": "Param description",
                    "default": 0
                }
            },
            "responses": {
                "200": {
                    "body": {
                        "application/json": {
                            "schema": "{\n\t"$schema": "http://json-schema.org/schema",\n\t"type": "object",\n\t"description": "A canonical song",\n\t"properties": {\n\t\t"title": {\n\t\t\t"type": "String"\n\t\t},\n\t\t"artist": {\n\t\t\t"type": "String"\n\t\t}\n\t},\n\t"required": ["title", "artist"]\n}"
                        }
                    }
                }
            }
        }
    }
}

Writting CompoSR phrases

All the phrases are wrapped inside this Function closure, meaning you can access any of it's params:

function phrase(req, res, next, corbelDriver, corbel, ComposerError, domain, _, q, request, compoSR){
  //Your phrase code
}

• q : A library for promises
• _: Lodash, a library for modular utilities
• request: Simplified HTTP request client
• ComposerError: Our custom error manager. new ComposerError('error:undefined:name', 'Please insert a name', 400)
• domain : Your domain name
• req, res, next : express request parameters
• corbel: Corbel JavaScript SDK with an extended corbel.generateDriver function that generates corbelDriver instances with the correct urlBase.
• corbelDriver : An instance of corbelDriver provided by corbel, instantiated with your Authorization header if provided
• compoSR : A snippet runner

count value in collections query

{
    "url": "countExample",
    "get": {
        "code": "CORBEL-JS_SNIPPET"
    }
}

where code should be a string with this corbel-js snippet:

var count;
corbelDriver.resources.collection('test:ComposrTest').get(undefined, {
    aggregation: {
        $count: '*'
    }
}).then(function(response) {
    count = response.data.count;
    return corbelDriver.resources.collection('test:ComposrTest').get();
}).then(function(response) {
    res.send({
        data: response.data,
        'count': count
    });
}).catch(function(error) {
    res.send(error);
});

Path & query parameters

{
    "url": "paramsExample/:pathparam",
    "get": {
        "code": "res.status(200).send('path param: ' + req.params.pathparam + ',  query param: ' + req.query.queryparam);"
    }
}

Reference

• corbel-js API
• Request object
• Response object
• RAML for phrase definition

API design best practices

Naming

• Use nouns not verbs
• Use plural nouns

Resource	GET (read)	POST (create)	PUT (update)	DELETE
/cars	Returns a list of cars	Create a new ticket	Bulk update of cars	Delete all cars
/cars/711	Returns a specific car	Method not allowed (405)	Updates a specific ticket	Deletes a specific ticket
/purchase	Get al purchases	Create a new purchase	Bulk update of purschases	Delete all purchases
/purchase/85	Returns a purchase	Method not allowed (405)	Updates a specific purchase	Delete all purchases

Resource GET read POST create PUT update DELETE /cars Returns a list of cars Create a new ticket Bulk update of cars Delete all cars /cars/711 Returns a specific car Method not allowed (405) Deletes a specific ticket

Versioning your phrases

A simple way to achieve this is definning the phrase version in the url, like this

{
    "url": "v1/paramsExample/:pathparam",
    "get": { ... }
}

A phrase version should change only if the phrase contract is broken

Reference

• APIgee
• Principios de diseño de APIs REST
• Best Practices for Designing a Pragmatic RESTful API
• REST API Resoruces

Run in a docker container

• clone repo

• build image

  docker build -t <username>/corbel-composer .
  

• run container

  docker run -d -p 3000:3000 --name="corbel-composer"  <username>/corbel-composer
  

• start/stop container

  docker start/stop corbel-composer
  

Tests

npm test

Coverage

grunt test:coverage

Debug

Requires node-inspector

npm install -g node-inspector

• Server

  npm run debug
  

• Tests

  npm run test:debug
  

Example code for phrases

Login a client/application

Prerequisites for login a client/application: Generate a jwt

NodeJS example

var corbel = require('corbel-js');
 
function generateAssertion(claims, clientSecret) {
  claims.aud = corbel.Iam.AUD;
  return corbel.jwt.generate(claims, clientSecret);
}
 
var claims = {
  iss: credentials.clientId,
  scope: credentials.scopes
};
 
var jwt = generateAssertion(claims, credentials.clientSecret);
 
//Make a POST request to the login client phrase with jwt in the body
/*
 Expect an object containing
  {
    accessToken : '',
    expiresAt : ''
  }
*/

---

Login client/application phrase code

if (!req.body || !req.body.jwt) {
  res.status(401).send(new ComposerError('error:jwt:undefined', '', 401));
}
var corbelDriver = corbel.generateDriver({iamToken: ''});
 
/*
 * Required claims:
 * iss: CLIENT_ID
 * aud: 'http://iam.bqws.io'
 * scope: 'scope1 scope2'
 * exp: epoch + 1h
 */
corbelDriver.iam.token().create({
  jwt: req.body.jwt
}).then(function(response) {
  //Enable assets access
  corbelDriver.assets().access();
  res.send(response.data);
}).catch(function(err){
  compoSR.run('global:parseError', { err : err, res : res});
});

Login a user

Prerequisites for login a user: Generate a jwt

NodeJS example

var corbel = require('corbel-js');
 
function generateAssertion(claims, clientSecret) {
  claims.aud = corbel.Iam.AUD;
  return corbel.jwt.generate(claims, clientSecret);
}
 
//Note that appCredentials contains the credentials of the client app
 
var claims = {
  iss: appCredentials.clientId,
  'basic_auth.username': userCredentials.username,
  'basic_auth.password': userCredentials.password,
  scope: userCredentials.scopes
};
 
var jwt = generateAssertion(claims, appCredentials.clientSecret);
 
//Make a POST request to the login user phrase with jwt in the body
 
/*
 Expect an object containing
  {
    tokenObject: {
      accessToken : '',
      expiresAt : '',
      refreshToken : ''
    },
    user: {
      ...
    }
  }
*/

---

Login user phrase code

if (!req.body || !req.body.jwt) {
  return res.status(401).send(new ComposerError('error:jwt:undefined', '', 401));
}
var corbelDriver = corbel.generateDriver({iamToken: ''});
 
var tokenObject;
 
/*
 * Request a session token for the user
 * Required claims:
 * iss: CLIENT_ID
 * basic_auth.username: USERNAME
 * basic_auth.password: PASSWORD
 * aud: 'http://iam.bqws.io'
 * scope: 'scope1 scope2'
 * exp: epoch + 1h
 */
return corbelDriver.iam.token().create({
  jwt : req.body.jwt
}).then(function(response){
  //Enable assets access (only for users)
  corbelDriver.assets().access();
  
  //Tenemos el token de usuario, asimismo tambien el refresh y el expires
  tokenObject = response.data;
 
  //Recreamos el corbelDriver con los settings del usuario
  corbelDriver = corbel.generateDriver({
    iamToken : tokenObject
  });
 
  //Obtain the logged user data
  return corbelDriver.iam.user('me').get();
}).then(function(response){
  return res.send({
    tokenObject: tokenObject,
    user: response.data
  });
}).catch(function(err){
  return compoSR.run('global:parseError', { err : err, res : res});
});

Refresh a token

Prerequisites for refreshing a user token: Generate a jwt with the refresh token

NodeJS example

var corbel = require('corbel-js');
 
function generateAssertion(claims, clientSecret) {
  claims.aud = corbel.Iam.AUD;
  return corbel.jwt.generate(claims, clientSecret);
}
 
//Note that appCredentials contains the credentials of the client app
 
var claims = {
  iss: appCredentials.clientId,
  'refresh_token': refresh_token,
  scope: userCredentials.scopes
};
 
var jwt = generateAssertion(claims, appCredentials.clientSecret);
 
//Make a POST request to the refresh token phrase with jwt in the body
 
/*
 Expect an object containing
 {
   accessToken : '',
   expiresAt : '',
   refreshToken : ''
 }
*/

---

Refresh token phrase code

if (!req.body || !req.body.jwt) {
  res.status(400).send(new ComposerError('error:jwt:undefined', 'JWT is missing', 400));
  return false;
}
var decoded = corbel.jwt.decode(req.body.jwt);
if(Object.keys(decoded).length === 0){
  res.status(400).send(new ComposerError('error:jwt:malformed', 'Your JWT is malformed', 400));
  return false;
}
 
if(!decoded.refresh_token){
  res.status(400).send(new ComposerError('error:jwt:refresh_token:missing', 'Add the refresh_token property', 400));
  return false;
}else{
 var refreshTokenDecoded = corbel.jwt.decode(decoded.refresh_token);
 if(Object.keys(refreshTokenDecoded).length === 0){
   res.status(400).send(new ComposerError('error:jwt:refresh_token:malformed', 'Your refresh_token is malformed', 400));
  return false;
 }
}
var corbelDriver = corbel.generateDriver({iamToken: ''});
 
/*
 * Required claims:
 * iss: CLIENT_ID
 * refresh_token: REFRESH_TOKEN
 * aud: 'http://iam.bqws.io'
 * scope: 'scope1 scope2'
 * exp: epoch + 1h
 */
corbelDriver.iam.token().create({
    jwt : req.body.jwt
  })
  .then(function(response){
    res.send(response.data);
  })
  .catch(function(err){
    compoSR.run('global:parseError', { err : err, res : res});
  });

Logout a user

Prerequisites for login out a user: have an accessToken

NodeJS example

var http = require('http');
 
var accessToken = "xxxxx":
 
var post_options = {
  host: 'composrendpoint.composr',
  path: '/logoutuser',
  method: 'POST',
  headers: {
    'Authorization': accessToken
  }
};
 
 
//Make a POST request to the logout user phrase with an Authorization header
http.request(post_options, function(res) {
  //Expect 204 for a good logout, 401 for unauthorized
});
 

---

Logout user phrase code

if (!req.get('Authorization')) {
  res.status(401).send(new ComposerError('error:unauthorized', 'Authorization missing', 401));
}
 
var method =  req.params.type && req.params.type === 'all' ? 'disconnect' : 'signOut';
 
/*
 * Disconnects a user session
 */
corbelDriver.iam.user('me')[method]()
  .then(function(response){
    res.send(response.data);
  }).catch(function(err){
    compoSR.run('global:parseError', { err : err, res : res});
  });

Logout a user from all devices:

if (!req.get('Authorization')) {
  throw new ComposerError('error:unauthorized', 'Authorization missing', 401);
}
 
/*
 * Disconnects a user session
 */
 
corbelDriver.iam.user('me')
  .disconnect()
  .then(function(response){
    res.send(response.data);
  }).catch(function(err){
    compoSR.run('global:parseError', { err : err, res : res});
  });

Return current user info

corbelDriver.iam.user('me').get();

Library

Get library phrase code

if (!req.get('Authorization')) {
  throw new ComposerError('error:authorization:undefined', '', 401);
}
 
var books = [];
 
for( var i = 0; i < 20; i++){
  books.push({
     _id: Date.now(),
     _createdAt: new Date("2015-05-08T14:37:37.628Z"),
     _src_id: "Libranda",
     _dst_id: "books:Book/7004c092",
     isbn: "9788415564430",
     distributorId: "LIBR",
     title: "Remedio: la geografía",
     synopsis: "",
     authors: [
         {
             name: "Luigi Pirandello",
             biographicalNote: ""
         }
     ],
     rawCategories: [
         "FA"
     ],
     storeCategories: [
         "F",
         "FA"
     ],
     cover: "http://www.nordicalibros.com/upload/fgr02102012145613.jpg",
     format: "epub",
     language: "spa",
     publisherGroupName: "Nordica Libros",
     publishingTime: 1347753600000,
     _updatedAt: new Date("2015-05-08T14:37:37.628Z"),
     _order: 1
  });
}
 
res.send({
  data : books,
  count : books.length
});

Code snippets

Code snippets are a minor form of phrases, they are accesible through the compoSR object on your phrases.

You can run your code snippets by executing compoSR.run('snippetName', params); where params is anything you want it to be. From your snippets you will be allowed to access to the params variable and the compoSR object itself.

compoSR will be allowed to access any snippets defined in your domain and your parent domains.

For example, _silkroad:composer will be able to access all the _silkroad:composer snippets and all the _silkroad snippets. If a snippet has the same name on both of the domains, the one with a deepest hierarchy will overwrite the first one.

Let's take a look at it:

• Given this snippets:

var snippets = {
  'domainName' : [
    {
      name : 'myFunction',
      code : 'compoSR.run("hello", "world")'
    },
    {
      name : 'hello',
      code: 'console.log(params);'
    }
  ],
  'domainName:childDomain' : [
    {
      name : 'hello',
      code: 'console.log("I am the child: ", params);'
    }
  ],
}

• If we run the myFunction snippet, accesing from a client that belongs to the domain named domainName:childDomain it will show this:

compoSR.run('myFunction');
//=> I am the child: world

• If the client or user belongs to the domain named domainName and we execute the same function we'll get:

compoSR.run('myFunction');
//=> hello world

Logs

Logs are written to the linux syslog and in the logs folder.

You can set logFile and logLevel in your config file.

Available log levels can be found at winston's npm page:

• debug
• info
• warn
• error

You can disable syslog by setting syslog property to false in the config file.