3 from StringIO import StringIO
4 from datetime import datetime, timedelta
5 from sfa.util.xrn import *
6 from sfa.util.plxrn import hostname_to_urn
7 from sfa.util.enumeration import Enum
8 from sfa.util.faults import SfaNotImplemented, InvalidRSpec, InvalidRSpecElement
17 for (key, value) in filter.items():
22 if isinstance(value, str):
23 filter_list.append('%s="%s"' % (key, value))
24 elif isinstance(value, list):
25 filter_list.append('contains("%s", %s)' % (' '.join(map(str, value)), key))
27 xpath = ' and '.join(filter_list)
28 xpath = '[' + xpath + ']'
31 # recognized top level rspec elements
32 RSpecElements = Enum('NETWORK', 'NODE', 'SLIVER', 'INTERFACE', 'LINK', 'VLINK')
35 def __init__(self, element_type, name, path):
36 if not element_type in RSpecElements:
37 raise InvalidRSpecElement(element_type)
38 self.type = element_type
43 header = '<?xml version="1.0"?>\n'
44 template = """<RSpec></RSpec>"""
51 def __init__(self, rspec="", namespaces={}, type=None, user_options={}):
53 self.user_options = user_options
56 self.parse_rspec(rspec, namespaces)
64 # eg. 2011-03-23T19:53:28Z
65 date_format = '%Y-%m-%dT%H:%M:%SZ'
66 now = datetime.utcnow()
67 generated_ts = now.strftime(date_format)
68 expires_ts = (now + timedelta(hours=1)).strftime(date_format)
69 self.parse_rspec(self.template, self.namespaces)
70 self.xml.set('expires', expires_ts)
71 self.xml.set('generated', generated_ts)
73 def parse_rspec(self, rspec, namespaces={}):
75 parse rspec into etree
77 parser = etree.XMLParser(remove_blank_text=True)
79 tree = etree.parse(rspec, parser)
81 # 'rspec' file doesnt exist. 'rspec' is proably an xml string
83 tree = etree.parse(StringIO(rspec), parser)
85 raise InvalidRSpec(str(e))
86 self.xml = tree.getroot()
88 self.namespaces = namespaces
90 def validate(self, schema):
92 Validate against rng schema
95 relaxng_doc = etree.parse(schema)
96 relaxng = etree.RelaxNG(relaxng_doc)
97 if not relaxng(self.xml):
98 error = relaxng.error_log.last_error
99 message = "%s (line %s)" % (error.message, error.line)
100 raise InvalidRSpec(message)
103 def xpath(self, xpath):
104 return self.xml.xpath(xpath, namespaces=self.namespaces)
106 def register_element_type(self, element_type, element_name, element_path):
107 if element_type not in RSpecElements:
108 raise InvalidRSpecElement(element_type, extra="no such element type: %s. Must specify a valid RSpecElement" % element_type)
109 self.elements[element_type] = RSpecElement(element_type, element_name, element_path)
111 def get_element_type(self, element_type):
112 if element_type not in self.elements:
113 msg = "ElementType %s not registerd for this rspec" % element_type
114 raise InvalidRSpecElement(element_type, extra=msg)
115 return self.elements[element_type]
117 def add_attribute(self, elem, name, value):
119 Add attribute to specified etree element
121 opt = etree.SubElement(elem, name)
124 def add_element(self, name, attrs={}, parent=None, text=""):
126 Generic wrapper around etree.SubElement(). Adds an element to
127 specified parent node. Adds element to root node is parent is
132 element = etree.SubElement(parent, name)
135 if isinstance(attrs, dict):
137 element.set(attr, attrs[attr])
140 def remove_attribute(self, elem, name, value):
142 Removes an attribute from an element
145 opts = elem.iterfind(name)
148 if opt.text == value:
151 def remove_element(self, element_name, root_node = None):
153 Removes all occurences of an element from the tree. Start at
154 specified root_node if specified, otherwise start at tree's root.
159 if not element_name.startswith('//'):
160 element_name = '//' + element_name
162 elements = root_node.xpath('%s ' % element_name, namespaces=self.namespaces)
163 for element in elements:
164 parent = element.getparent()
165 parent.remove(element)
167 def get_element_attributes(self, elem=None, depth=0):
169 elem = self.root_node
170 attrs = dict(elem.attrib)
171 attrs['text'] = str(elem.text).strip()
172 if isinstance(depth, int) and depth > 0:
173 for child_elem in list(elem):
174 key = str(child_elem.tag)
176 attrs[key] = [self.get_element_attributes(child_elem, depth-1)]
178 attrs[key].append(self.get_element_attributes(child_elem, depth-1))
180 attrs['child_nodes'] = list(elem)
183 def find(self, element_type, filter={}, depth=0):
184 elements = [self.get_element_attributes(element, depth=depth) for element in \
185 self.find_elements(element_type, filter)]
188 def find_elements(self, element_type, filter={}):
190 search for a registered element
192 if element_type not in self.elements:
193 msg = "Unable to search for element %s in rspec, expath expression not found." % \
195 raise InvalidRSpecElement(element_type, extra=msg)
196 rspec_element = self.get_element_type(element_type)
197 xpath = rspec_element.path + XpathFilter.xpath(filter)
198 return self.xpath(xpath)
200 def merge(self, in_rspec):
205 Optional method which inheriting classes can choose to implent.
209 def _process_slivers(self, slivers):
211 Creates a dict of sliver details for each sliver host
213 @param slivers a single hostname, list of hostanmes or list of dicts keys on hostname,
214 Returns a list of dicts
216 if not isinstance(slivers, list):
219 for sliver in slivers:
220 if isinstance(sliver, dict):
222 elif isinstance(sliver, basestring):
223 dicts.append({'hostname': sliver})
229 def toxml(self, cleanup=False):
232 return self.header + etree.tostring(self.xml, pretty_print=True)
234 def save(self, filename):
235 f = open(filename, 'w')
236 f.write(self.toxml())
239 if __name__ == '__main__':
240 rspec = RSpec('/tmp/resources.rspec')
242 #rspec.register_element_type(RSpecElements.NETWORK, 'network', '//network')
243 #rspec.register_element_type(RSpecElements.NODE, 'node', '//node')
244 #print rspec.find(RSpecElements.NODE)[0]
245 #print rspec.find(RSpecElements.NODE, depth=1)[0]