root / api / util.py @ 4cf8adf8
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#
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# Copyright (c) 2010 Greek Research and Technology Network
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#
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from datetime import timedelta, tzinfo |
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from functools import wraps |
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from random import choice |
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from string import ascii_letters, digits |
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from time import time |
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from traceback import format_exc |
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from wsgiref.handlers import format_date_time |
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from django.conf import settings |
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from django.http import HttpResponse |
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from django.template.loader import render_to_string |
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from django.utils import simplejson as json |
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from synnefo.api.faults import Fault, BadRequest, ItemNotFound, ServiceUnavailable |
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from synnefo.db.models import SynnefoUser, Image, ImageMetadata, VirtualMachine, VirtualMachineMetadata |
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import datetime |
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import dateutil.parser |
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import logging |
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class UTC(tzinfo): |
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def utcoffset(self, dt): |
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return timedelta(0) |
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def tzname(self, dt): |
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return 'UTC' |
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def dst(self, dt): |
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return timedelta(0) |
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def isoformat(d): |
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"""Return an ISO8601 date string that includes a timezon."""
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return d.replace(tzinfo=UTC()).isoformat()
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def isoparse(s): |
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"""Parse an ISO8601 date string into a datetime object."""
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if not s: |
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return None |
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try:
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since = dateutil.parser.parse(s) |
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utc_since = since.astimezone(UTC()).replace(tzinfo=None)
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except ValueError: |
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raise BadRequest('Invalid changes-since parameter.') |
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now = datetime.datetime.now() |
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if utc_since > now:
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raise BadRequest('changes-since value set in the future.') |
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if now - utc_since > timedelta(seconds=settings.POLL_LIMIT):
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raise BadRequest('Too old changes-since value.') |
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return utc_since
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def random_password(length=8): |
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pool = ascii_letters + digits |
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return ''.join(choice(pool) for i in range(length)) |
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def get_user(): |
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# XXX Placeholder function, everything belongs to a single SynnefoUser for now
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try:
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return SynnefoUser.objects.all()[0] |
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except IndexError: |
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raise Unauthorized
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def get_vm(server_id): |
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"""Return a VirtualMachine instance or raise ItemNotFound."""
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try:
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server_id = int(server_id)
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return VirtualMachine.objects.get(id=server_id)
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except ValueError: |
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raise BadRequest('Invalid server ID.') |
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except VirtualMachine.DoesNotExist:
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raise ItemNotFound('Server not found.') |
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def get_vm_meta(server_id, key): |
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"""Return a VirtualMachineMetadata instance or raise ItemNotFound."""
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try:
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server_id = int(server_id)
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return VirtualMachineMetadata.objects.get(meta_key=key, vm=server_id)
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except VirtualMachineMetadata.DoesNotExist:
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raise ItemNotFound('Metadata key not found.') |
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def get_image(image_id): |
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"""Return an Image instance or raise ItemNotFound."""
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try:
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image_id = int(image_id)
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return Image.objects.get(id=image_id)
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except Image.DoesNotExist:
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raise ItemNotFound('Image not found.') |
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def get_image_meta(image_id, key): |
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"""Return a ImageMetadata instance or raise ItemNotFound."""
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try:
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image_id = int(image_id)
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return ImageMetadata.objects.get(meta_key=key, image=image_id)
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except ImageMetadata.DoesNotExist:
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raise ItemNotFound('Metadata key not found.') |
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def get_request_dict(request): |
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"""Returns data sent by the client as a python dict."""
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data = request.raw_post_data |
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if request.META.get('CONTENT_TYPE').startswith('application/json'): |
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try:
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return json.loads(data)
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except ValueError: |
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raise BadRequest('Invalid JSON data.') |
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else:
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raise BadRequest('Unsupported Content-Type.') |
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def update_response_headers(request, response): |
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if request.serialization == 'xml': |
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response['Content-Type'] = 'application/xml' |
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elif request.serialization == 'atom': |
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response['Content-Type'] = 'application/atom+xml' |
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else:
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response['Content-Type'] = 'application/json' |
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if settings.TEST:
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response['Date'] = format_date_time(time())
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def render_metadata(request, metadata, use_values=False, status=200): |
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if request.serialization == 'xml': |
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data = render_to_string('metadata.xml', {'metadata': metadata}) |
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else:
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d = {'metadata': {'values': metadata}} if use_values else {'metadata': metadata} |
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data = json.dumps(d) |
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return HttpResponse(data, status=status)
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def render_meta(request, meta, status=200): |
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if request.serialization == 'xml': |
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data = render_to_string('meta.xml', {'meta': meta}) |
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else:
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data = json.dumps({'meta': {meta.meta_key: meta.meta_value}})
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return HttpResponse(data, status=status)
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def render_fault(request, fault): |
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if settings.DEBUG or settings.TEST: |
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fault.details = format_exc(fault) |
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if request.serialization == 'xml': |
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data = render_to_string('fault.xml', {'fault': fault}) |
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else:
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d = {fault.name: {'code': fault.code, 'message': fault.message, 'details': fault.details}} |
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data = json.dumps(d) |
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resp = HttpResponse(data, status=fault.code) |
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update_response_headers(request, resp) |
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return resp
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def request_serialization(request, atom_allowed=False): |
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"""Return the serialization format requested.
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Valid formats are 'json', 'xml' and 'atom' if `atom_allowed` is True.
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"""
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path = request.path |
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if path.endswith('.json'): |
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return 'json' |
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elif path.endswith('.xml'): |
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return 'xml' |
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elif atom_allowed and path.endswith('.atom'): |
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return 'atom' |
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for item in request.META.get('HTTP_ACCEPT', '').split(','): |
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accept, sep, rest = item.strip().partition(';')
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if accept == 'application/json': |
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return 'json' |
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elif accept == 'application/xml': |
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return 'xml' |
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elif atom_allowed and accept == 'application/atom+xml': |
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return 'atom' |
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return 'json' |
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def api_method(http_method=None, atom_allowed=False): |
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"""Decorator function for views that implement an API method."""
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def decorator(func): |
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@wraps(func)
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def wrapper(request, *args, **kwargs): |
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try:
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request.serialization = request_serialization(request, atom_allowed) |
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if http_method and request.method != http_method: |
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raise BadRequest('Method not allowed.') |
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resp = func(request, *args, **kwargs) |
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update_response_headers(request, resp) |
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return resp
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except Fault, fault:
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return render_fault(request, fault)
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except BaseException, e: |
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logging.exception('Unexpected error: %s' % e)
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fault = ServiceUnavailable('Unexpected error')
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return render_fault(request, fault)
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return wrapper
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return decorator
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