GCat Service

The gCube Science Catalogue Service is a RESTful web service based on the principles defined in gCube Catalogue

Request

URL

The URL used to interact with the Science Catalogue Service is composed of two parts:

• Base Service URL (e.g. https:/catalogue.d4science.org/science-catalogue)
• Specific API (e.g. /organizations)

D4Science infrastructure uses cloud facilities allowing to replicate a service to achieve failover and load balancing.

Science Catalogue Service instances can be deployed and undeployed dynamically. For such a reason the Base Service URL MUST NOT be hard-cabled in the code because it can change over time.

To dynamically discover the Base Service URL please use the information system.

You need to discover gCore Resource having:

• class : DataCatalogue
• name : science-catalogue

HTTP Headers

gCube Authorization Token

Any request performed to Science Catalogue MUST contains the gCube Authorization Token.

This is done using the HTTP Header gcube-token

gcube-token: YOUR-TOKEN

Retrieve your gCube Authorization Token

the gCube Authorization Token is a UUID bound to yourself and a given Infrastructure context. To retrieve it, you just need to go to a VRE for which you are interested and use the Authorisation Options portlet (see below)

Click on Show button and select the token.

Content Type

Any request must contain the indication of the interested content type.

For any operation returning a result, the client must specify the Accept HTTP Header.

Accept: application/json

For any operation sending content to the service, it is necessary to specify the Content-Type HTTP Header.

Content-Type: application/json

Actually, the service accepts and returns only JSON objects.

Except for a profile which can be also requested in XML.

HTTP Statuses

Any successful operation returns 200 OK status code except for create operation which return 201 Created.

The most common error status a client can obtain are

• 400 Bad Request used to indicate a clients error [tools.ietf.org/html/rfc7231#section-6.5.1 tools.ietf.org/html/rfc7231#section-6.5.1]
• 401 Unauthorized used to indicate that the client does not provided the gcube-token HTTP Header or the clinet has not enough right to perform such request https://tools.ietf.org/html/rfc7235#section-3.1
• 404 Not Found
• 405 Method Not Allowed
• 500 Internal Server Error

A complete list of HTTP Status can be found here: https://httpstatuses.com/

HTTP Methods

To be RESTful compliant Science Catalogue uses standard HTTP Methods to perform a listing of collections and CRUD (Create Read Update Delete) operations on instances.

Operation	HTTP Method	URL	Success HTTP Status
List	GET	/{COLLECTION}	200 OK
Create	POST	/{COLLECTION}	201 Created
Read	GET	/{COLLECTION}/{INSTANCE_ID}	200 OK
Update	PUT	/{COLLECTION}/{INSTANCE_ID}	200 OK
Patch	PATCH	/{COLLECTION}/{INSTANCE_ID}	200 OK
Delete	DELETE	/{COLLECTION}/{INSTANCE_ID}	200 OK
Purge	PURGE	/{COLLECTION}/{INSTANCE_ID}	200 OK
Purge	DELETE	/{COLLECTION}/{INSTANCE_ID}?purge=true	200 OK

Where:

• {COLLECTION} is the plural name of the entity type
• {INSTANCE_ID} is an identification which enables to univocally identify the instance in the collection

You can find more information about this at https://restfulapi.net/http-methods/

PURGE Method is not a standard HTTP Method but is a widely used in service which requires this action (e.g. Varnish, Squid)

The Science Catalogue provide support for this method but to support a wider range of clients it also provides the Purge action via DELETE with the additional get parameter

purge=true

Collections

• Group
• Item
• Resource
• License
• Organization
• User
• Profile
• Namespace

Group Collection

Operation	HTTP Method	URL
List	GET	/groups
Create	POST	/groups
Read	GET	/groups/{NAME}
Update	PUT	/groups/{NAME}
Patch	PATCH	/groups/{NAME}
Delete	DELETE	/groups/{NAME}
Purge	PURGE	/groups/{NAME}
Purge	DELETE	/groups/{NAME}?purge=true

Item Collection

Operation	HTTP Method	URL
List	GET	/items
Create	POST	/items
Read	GET	/items/{NAME}
Update	PUT	/items/{NAME}
Delete	DELETE	/items/{NAME}
Purge	PURGE	/items/{NAME}
Purge	DELETE	/items/{NAME}?purge=true

Resource Collection

Operation	HTTP Method	URL
List	GET	/items/{NAME}/resources
Create	POST	/items/{NAME}/resources
Read	GET	/items/{NAME}/resources/{ID}
Update	PUT	/items/{NAME}/resources/{ID}
Delete	DELETE	/items/{NAME}/resources/{ID}

License Collection

Operation	HTTP Method	URL
List	GET	/licenses

Organization Collection

Operation	HTTP Method	URL
List	GET	/organizations
Create	POST	/organizations
Read	GET	/organizations/{NAME}
Update	PUT	/organizations/{NAME}
Patch	PATCH	/organizations/{NAME}
Delete	DELETE	/organizations/{NAME}
Purge	PURGE	/organizations/{NAME}
Purge	DELETE	/organizations/{NAME}?purge=true

User Collection

Operation	HTTP Method	URL
List	GET	/users
Create	POST	/users
Read	GET	/users/{NAME}
Update	PUT	/users/{NAME}
Delete	DELETE	/users/{NAME}

Profile Collection

Operation	HTTP Method	URL
List	GET	/profiles
Read	GET	/profiles/{NAME}

A profile is defined using XML. It is possible to get the original XML definition using 'Accept' HTTP Header.

Accept : application/xml

instead of

Accept : application/json

Namespace Collection

Operation	HTTP Method	URL
List	GET	/namespaces