Revision as of 10:44, 22 December 2017

Overview

A RESTful service providing functions for create, update, read a json object on MongoDB

Key features

The core of the service is java based. It offers a interface for performing CRUD operation through a remote backend over JSON object:

• Create
• Read
• Update
• Delete

Design and Architecture

The architecture implements a multiton pattern. The records are collected in two separated collection: the first one is a collection dedicated to a single SmartApps, the second One is a collection that collects all the records of all the smartApplications.

Access Mode

The Endppoint of the SStorageRest service can be discovered by IS-Collector service under the SmartArea VO. For accessing to the service it's needed to use the ic-client library in the following way:

               SimpleQuery query = queryFor(ServiceInstance.class);
               query.addCondition("$resource/Data/gcube:ServiceClass/text() eq sc").addCondition("$resource/Data/gcube:ServiceName/text() eq sn");
               DiscoveryClient<ServiceInstance> client = clientFor(ServiceInstance.class);
               List<ServiceInstance> resources = client.submit(query);

where "sc" and "sn" are respectively the "ServiceClass" and the "ServiceName" of the resource. In this case the "ServiceClass" should be set to: "content-management", and the "ServiceName" should be set to "storage".

The method client.submit(query) return a List of resources (in this case with only one resource) that match the query parameters.

For retrieving the hostname of the SStorageRest service, it's needed to parse the resource retrieved in the following way:

String server addresses=resource.profile().accessPoints().get(0).address();

where "resource" is the object returned by the query. the field address can contains one or more server separated by comma.

Supported Operations

• create: implemented by http POST method;
• read : implemented by http GET method;
• update: implemented by http PUT method;
• delete: implemented by http DELETE method.

Getting-Started

We introduce the API of the SStorageRest through a set of examples.

Note that, in all the examples, we submit queries to the SStorageRest service. We then need to make sure that we do so in a given scope by a personal gcube-token

Maven artifacts

The service package is downloadable from the following nexus server: http://maven.research-infrastructures.eu/nexus

<groupId>org.gcube.contentmanagement</groupId>
<artifactId>storage-service-rest</artifactId>
<version>...</version>

Usage examples

To insert (create) a new record in the system, we might use:

• POST n039.smart-applications.area.pi.cnr.it:8080/storage/rest/resources?gcube-token=xxxxxxxx

To read a object with ID# 33245:

• GET http://n039.smart-applications.area.pi.cnr.it:8080/storage/rest/resources/33245?gcube-token=xxxxxxxx The same URI would be used for PUT and DELETE, to update and delete, respectively.

Here are proposed URIs for products:

• POST http://n039.smart-applications.area.pi.cnr.it:8080/storage/rest/resources?gcube-token=xxxxxxxx for creating a new object.

• GET|PUT|DELETE http://n039.smart-applications.area.pi.cnr.it:8080/storage/rest/resources/33245?gcube-token=xxxxxxxx

for reading, updating, deleting object with id 66432, respectively.

For deleting all the objects in the collection:

• DELETE http://n039.smart-applications.area.pi.cnr.it:8080/storage/rest/resources?gcube-token=xxxxxxxx