Source code for dgitcore.contrib.metadata.default

#!/usr/bin/env python
"""Adapter to a metadata server that provides dataset tracking and other
services.

* enable: Enable this adapter
* url: URL to which the metadata must be posted
* token: Authentication token for the server

"""
import os, sys, requests, json
from dgitcore.plugins.metadata import MetadataBase
from dgitcore.exceptions import *
from dgitcore.config import get_config, ChoiceValidator, URLValidator, NonEmptyValidator

class BasicMetadata(MetadataBase):
    """
    Metadata backend for the datasets.

    Parameters
    ----------
    Configuration (token)
    """
    def __init__(self):
        self.enable = False
        self.token = None
        self.url = None
        super(BasicMetadata, self).__init__('basic-metadata',
                                              'v0',
                                              "Basic metadata server")

    def config(self, what='get', params=None):

        if what == 'get':
            return {
                'name': 'basic-metadata',
                'nature': 'metadata',
                'variables': ['enable', 'token', 'url'],
                'defaults': {
                    'enable': {
                        'value': "y",
                        "description": "Enable generic Metadata server?",
                        'validator': ChoiceValidator(['y','n'])
                    },
                    'token': {
                        'value': '',
                        'description': 'Provide API token to be used for posting',
                        'validator': NonEmptyValidator(),
                    },
                    'url': {
                        'value': '',
                        'description': 'URL to which metadata should be posted',
                        'validator': URLValidator()
                    },
                }
            }
        else:
            try:
                self.enable = params['basic-metadata']['enable']
            except:
                self.enable = 'n'
                return

            metadata = params['basic-metadata']
            self.enable     = metadata['enable']
            self.token      = metadata.get('token', None)
            self.url        = metadata.get('url', None)
            if self.enable == 'y':
                if self.token is None:
                    raise NetworkInvalidConfiguration("Missing token")
                if self.url is None:
                    raise NetworkInvalidConfiguration("Missing URL")


    def post(self, repo):
        """
        Post to the metadata server

        Parameters
        ----------

        repo
        """

        datapackage = repo.package

        url = self.url
        token = self.token
        headers = {
            'Authorization': 'Token {}'.format(token),
            'Content-Type': 'application/json'
        }

        try:
            r = requests.post(url,
                              data = json.dumps(datapackage),
                              headers=headers)

            return r
        except:
            raise NetworkError()
        return ""

def setup(mgr):

    obj = BasicMetadata()
    mgr.register('metadata', obj)