| 1 | ## |
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| 2 | |
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| 3 | """ |
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| 4 | The ConfigLoader loads in a particular configuration file that |
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| 5 | specifies the change definition to be run. |
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| 6 | """ |
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| 7 | import re |
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| 8 | import sys |
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| 9 | import os |
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| 10 | |
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| 11 | #from xml.parsers.expat import ParserCreate |
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| 12 | #from xml.dom.minidom import Document, Text |
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| 13 | from lxml import etree |
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| 14 | |
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| 15 | from device import Device |
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| 16 | from change import CHANGE_STATE, ChangeConditionFailure |
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| 17 | from provisioner import UserBailout |
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| 18 | import util |
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| 19 | |
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| 20 | from twisted.internet import defer, reactor |
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| 21 | from twisted.python import log as tlog |
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| 22 | |
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| 23 | import logging |
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| 24 | import debug |
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| 25 | |
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| 26 | log = logging.getLogger('modipy') |
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| 27 | |
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| 28 | xinclude_re = re.compile(r'.*<xi:include href=[\'\"](?P<uri>.*)[\'\"].*') |
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| 29 | |
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| 30 | class Namespace: |
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| 31 | """ |
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| 32 | A cascading namespace object that can refer to items in |
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| 33 | parent namespaces to resolve names if they do not exist |
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| 34 | in the current namespace. |
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| 35 | """ |
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| 36 | def __init__(self, name, namespace={}, parent=None): |
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| 37 | |
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| 38 | self.parent = parent |
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| 39 | self.namespace = namespace |
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| 40 | |
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| 41 | def __getitem__(self, key): |
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| 42 | """ |
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| 43 | Implement dictionary interface |
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| 44 | """ |
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| 45 | try: |
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| 46 | return self.namespace[key] |
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| 47 | except KeyError: |
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| 48 | if self.parent is not None: |
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| 49 | return self.parent[key] |
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| 50 | else: |
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| 51 | raise |
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| 52 | |
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| 53 | def __setitem__(self, key, value): |
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| 54 | self.namespace[key] = value |
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| 55 | |
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| 56 | def keys(self): |
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| 57 | keys = self.namespace.keys() |
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| 58 | |
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| 59 | if self.parent is not None: |
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| 60 | pkeys = self.parent.keys() |
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| 61 | for pkey in pkeys: |
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| 62 | if pkey not in keys: |
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| 63 | keys.append(pkey) |
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| 64 | pass |
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| 65 | pass |
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| 66 | pass |
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| 67 | |
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| 68 | return keys |
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| 69 | |
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| 70 | def has_key(self, key): |
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| 71 | if self.namespace.has_key(key): |
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| 72 | return True |
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| 73 | else: |
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| 74 | if self.parent is not None: |
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| 75 | return self.parent.has_key(key) |
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| 76 | else: |
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| 77 | return False |
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| 78 | pass |
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| 79 | pass |
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| 80 | |
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| 81 | def update(self, dict): |
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| 82 | for key in dict: |
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| 83 | self.namespace[key] = dict[key] |
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| 84 | |
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| 85 | def __iter__(self): |
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| 86 | log.debug("Creating a Namespace iterator") |
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| 87 | |
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| 88 | # initialise iterators |
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| 89 | if self.parent is not None: |
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| 90 | log.debug("started parent iterator") |
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| 91 | return self.parent.__iter__() |
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| 92 | |
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| 93 | self.namespace.__iter__() |
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| 94 | log.debug("started my iterator") |
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| 95 | return self |
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| 96 | |
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| 97 | def next(self): |
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| 98 | if self.parent is not None: |
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| 99 | try: |
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| 100 | return self.parent.next() |
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| 101 | except StopIteration: |
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| 102 | return self.namespace.next() |
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| 103 | else: |
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| 104 | try: |
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| 105 | return self.namespace.next() |
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| 106 | except AttributeError: |
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| 107 | raise StopIteration |
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| 108 | |
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| 109 | def items(self): |
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| 110 | log.debug("Using namespace.items()!") |
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| 111 | items = [] |
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| 112 | if self.parent is not None: |
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| 113 | items.extend( self.parent.items() ) |
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| 114 | items.extend( self.namespace.items() ) |
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| 115 | |
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| 116 | return items |
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| 117 | |
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| 118 | class ConfigLoader: |
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| 119 | """ |
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| 120 | A ConfigLoader is used to load in a change configuration and |
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| 121 | set up all the objects that define the change. |
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| 122 | """ |
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| 123 | |
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| 124 | def __init__(self, options=None, devices=[]): |
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| 125 | |
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| 126 | self.doc = None |
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| 127 | |
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| 128 | self.options = options |
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| 129 | |
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| 130 | self.provisioners = {} |
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| 131 | self.devices = {} |
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| 132 | self.change_templates = {} |
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| 133 | self.changes = {} |
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| 134 | self.iterators = {} |
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| 135 | |
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| 136 | self.pending_changes = [] |
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| 137 | self.change_success = [] |
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| 138 | self.change_failure = [] |
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| 139 | self.backout_success = [] |
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| 140 | self.backout_failure = [] |
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| 141 | |
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| 142 | log.debug("created ConfigLoader") |
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| 143 | |
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| 144 | if options.configfile: |
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| 145 | self.parse(options.configfile) |
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| 146 | pass |
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| 147 | |
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| 148 | # Add devices specified on the commandline to the active configuration |
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| 149 | if len(devices) != 0: |
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| 150 | for dev in devices: |
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| 151 | # If a device given on the commandline is not present in the |
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| 152 | # configuration file, add it. |
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| 153 | if dev not in self.devices.keys(): |
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| 154 | log.info("Adding commandline specified device: '%s'" % dev) |
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| 155 | self.devices[dev] = Device(dev) |
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| 156 | pass |
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| 157 | pass |
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| 158 | # If devices other than those specified on the commandline |
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| 159 | # ARE present in the config file, remove the extra ones. |
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| 160 | # This means you can run a configuration on a subset of devices |
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| 161 | # by specifying the device name on the commandline. |
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| 162 | |
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| 163 | for dev in self.devices.keys(): |
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| 164 | if dev not in devices: |
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| 165 | log.info("Not using configured device '%s' (not on commandline)", dev) |
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| 166 | del self.devices[dev] |
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| 167 | pass |
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| 168 | |
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| 169 | def parse(self, configfile): |
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| 170 | """ |
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| 171 | Parse my configuration file. |
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| 172 | """ |
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| 173 | self.tree = etree.parse(configfile) |
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| 174 | |
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| 175 | # Process xincludes |
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| 176 | try: |
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| 177 | self.tree.xinclude() |
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| 178 | except etree.XIncludeError: |
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| 179 | log.error("XInclude of a file failed.") |
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| 180 | log.error("Use external tool such as xmllint to figure out why.") |
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| 181 | log.error("Sorry, but lxml.etree won't tell me exactly what went wrong.") |
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| 182 | raise |
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| 183 | |
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| 184 | # add the global namespace |
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| 185 | try: |
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| 186 | nsnode = self.tree.xpath('/config/namespace')[0] |
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| 187 | self.add_namespace(nsnode) |
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| 188 | except IndexError: |
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| 189 | self.global_namespace = {} |
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| 190 | |
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| 191 | # Add all my node types, in the order specified in the list |
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| 192 | for nodename in [ |
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| 193 | 'iterator', |
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| 194 | 'provisioner', |
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| 195 | 'device', |
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| 196 | 'changetemplate', |
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| 197 | 'change', |
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| 198 | # 'dependencies', |
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| 199 | ]: |
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| 200 | |
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| 201 | for node in self.tree.findall(nodename): |
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| 202 | # Find the function to call based on the name of |
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| 203 | # the object by using dynamic lookup |
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| 204 | # This will call 'add_iterator' for an iterator node, for example. |
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| 205 | funcname = 'add_%s' % nodename |
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| 206 | func = getattr(self, funcname) |
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| 207 | log.debug("calling %s with arg: %s", func, node) |
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| 208 | func(node) |
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| 209 | |
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| 210 | # Find all the prereq definitions |
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| 211 | prereqs = self.tree.findall('prereq') |
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| 212 | for node in prereqs: |
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| 213 | prereq_changename = node.text |
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| 214 | |
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| 215 | try: |
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| 216 | prereq_for = node.attrib['for'] |
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| 217 | except KeyError: |
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| 218 | # See if this prereq node is within a change node |
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| 219 | prereq_for = node.xpath("parent::*/change")[0].attrib['name'] |
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| 220 | log.debug("Using change name of '%s'", prereq_for) |
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| 221 | |
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| 222 | # find the change |
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| 223 | try: |
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| 224 | prereq_change = self.changes[prereq_changename] |
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| 225 | except KeyError: |
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| 226 | log.error("Cannot find change '%s' as prereq for change '%s'", prereq_changename, prereq_for) |
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| 227 | raise |
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| 228 | |
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| 229 | try: |
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| 230 | change_for = self.changes[prereq_for] |
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| 231 | except KeyError: |
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| 232 | log.error("Cannot find change '%s' with prereq of '%s'", prereq_for, prereq_changename) |
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| 233 | raise |
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| 234 | |
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| 235 | # add change as prereq |
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| 236 | change_for.pre_requisites.append(prereq_change) |
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| 237 | log.debug("Added change '%s' as prereq for change '%s'", prereq_changename, prereq_for) |
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| 238 | |
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| 239 | # once the parse has completed, do some post-parse setup |
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| 240 | self.process_dependencies() |
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| 241 | |
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| 242 | def add_iterator(self, node): |
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| 243 | """ |
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| 244 | Add an iterator, which is a list of dictionary name/value pairs |
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| 245 | that will be iterated over for a particular change step. |
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| 246 | """ |
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| 247 | iter_name = node.attrib['name'] |
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| 248 | iterlist = [] |
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| 249 | for ns in node.findall('dict'): |
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| 250 | iter_ns = {} |
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| 251 | for entry in ns.findall('entry'): |
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| 252 | item_name = entry.attrib['name'] |
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| 253 | item_value = entry.text |
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| 254 | iter_ns[item_name] = item_value |
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| 255 | pass |
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| 256 | iterlist.append(iter_ns) |
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| 257 | pass |
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| 258 | self.iterators[iter_name] = iterlist |
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| 259 | log.debug("Added iterator '%s': %s" % (iter_name, iterlist)) |
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| 260 | |
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| 261 | def add_provisioner(self, node): |
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| 262 | """ |
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| 263 | Add a provisioner to my configuration based on the parsed element. |
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| 264 | """ |
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| 265 | # Provisioner type is dynamic, as it supports the loading |
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| 266 | # of plugin modules at runtime, so we look up the type |
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| 267 | prov_klass = node.attrib['type'] |
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| 268 | prov_name = node.attrib['name'] |
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| 269 | |
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| 270 | # Copy the attribs into a dictionary for use as kwargs |
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| 271 | kwargs = {} |
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| 272 | for key in node.attrib: |
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| 273 | if key not in ['type', 'name']: |
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| 274 | kwargs[key] = node.attrib[key] |
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| 275 | |
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| 276 | log.debug("Attempting to create a '%s' provisioner", prov_klass) |
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| 277 | prov_module = __import__('provisioner') |
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| 278 | klass = getattr( prov_module, prov_klass ) |
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| 279 | try: |
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| 280 | provisioner = klass(prov_name, authoritarian=self.options.authoritarian, **kwargs) |
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| 281 | except TypeError, e: |
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| 282 | log.error("Incorrect parameter supplied for provisioner of type '%s'", prov_klass) |
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| 283 | raise e |
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| 284 | |
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| 285 | log.debug("created provisioner '%s': %s", prov_name, provisioner) |
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| 286 | |
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| 287 | # If there are further attributes for the provisioner, |
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| 288 | # handle them with the provisioner itself |
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| 289 | for subnode in node.xpath('*'): |
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| 290 | provisioner.parse_config_node(subnode) |
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| 291 | pass |
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| 292 | |
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| 293 | self.provisioners[prov_name] = provisioner |
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| 294 | |
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| 295 | def add_device(self, node): |
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| 296 | """ |
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| 297 | Add a device to my configuration based on the parsed element. |
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| 298 | """ |
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| 299 | device_name = node.attrib['name'] |
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| 300 | device = Device(device_name) |
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| 301 | |
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| 302 | log.debug("created device '%s': %s", device_name, device) |
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| 303 | |
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| 304 | # add an attribute for each sub-element |
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| 305 | for subnode in node.xpath('*'): |
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| 306 | log.debug("processing device subnode: %s", subnode.tag) |
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| 307 | attrib = subnode.tag |
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| 308 | value = subnode.text |
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| 309 | setattr(device, attrib, value) |
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| 310 | pass |
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| 311 | |
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| 312 | log.debug("my ip addr is: %s", device.ipaddress) |
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| 313 | self.devices[device_name] = device |
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| 314 | |
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| 315 | def add_changetemplate(self, node): |
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| 316 | """ |
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| 317 | Add a change template to my list of available templates. |
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| 318 | A change template is a change object that may not have |
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| 319 | all of its parameters set yet. |
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| 320 | """ |
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| 321 | log.debug("Adding change template...") |
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| 322 | # Create the change template object |
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| 323 | change_tmpl = self.create_change_object(node) |
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| 324 | |
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| 325 | # Set any namespaces |
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| 326 | self.set_change_namespace(change_tmpl, node) |
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| 327 | |
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| 328 | # Set change parameters that are common to all changes |
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| 329 | self.set_change_params(change_tmpl, node) |
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| 330 | |
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| 331 | # Set the optional change iterator |
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| 332 | self.set_change_iterator(change_tmpl, node) |
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| 333 | |
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| 334 | # Add an optional onfail mode |
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| 335 | self.set_change_onfail(change_tmpl, node) |
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| 336 | |
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| 337 | self.change_templates[change_tmpl.name] = change_tmpl |
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| 338 | |
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| 339 | return change_tmpl |
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| 340 | |
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| 341 | def add_change(self, node): |
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| 342 | """ |
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| 343 | When adding a change, check for some extra options such as a |
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| 344 | change template, which will cause this change to be based on |
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| 345 | an existing change template. |
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| 346 | """ |
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| 347 | log.debug("Adding change...") |
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| 348 | try: |
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| 349 | tmpl_name = node.attrib['template'] |
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| 350 | log.debug("Change is based on a template: '%s'", tmpl_name) |
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| 351 | # Do template based processing |
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| 352 | try: |
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| 353 | template = self.change_templates[tmpl_name] |
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| 354 | except KeyError: |
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| 355 | raise ValueError("Change template '%s' is not defined" % tmpl_name) |
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| 356 | |
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| 357 | change = template.copy() |
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| 358 | # Make sure we set the change name to the actual change, |
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| 359 | # not the name of the template |
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| 360 | change.name = node.attrib['name'] |
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| 361 | |
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| 362 | # Now do non-templated specific processing |
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| 363 | self.set_change_namespace(change, node) |
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| 364 | self.set_change_params(change, node) |
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| 365 | self.set_change_iterator(change, node) |
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| 366 | self.set_change_onfail(change, node) |
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| 367 | |
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| 368 | except KeyError: |
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| 369 | # Use the same processing stream as a template, with the |
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| 370 | # assumption that all the required parameters have been |
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| 371 | # defined. If they haven't, the change will fail. |
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| 372 | change = self.add_change_template(node) |
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| 373 | pass |
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| 374 | |
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| 375 | # If the change doesn't have a provisioner, use the first one |
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| 376 | # in our config by default. |
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| 377 | if getattr(change, 'provisioner', None) is None: |
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| 378 | log.info("Change '%s' has no provisioner. Using default.", change.name ) |
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| 379 | # FIXME: This should find the first *compatible* provisioner, |
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| 380 | # rather than just the first one. |
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| 381 | change.provisioner = self.provisioners.values()[0] |
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| 382 | pass |
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| 383 | |
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| 384 | self.changes[change.name] = change |
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| 385 | self.pending_changes.append( change ) |
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| 386 | |
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| 387 | def create_change_object(self, node): |
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| 388 | """ |
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| 389 | Create a change object from a node. |
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| 390 | This may be used as a change template, or a regular change. |
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| 391 | """ |
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| 392 | # Change type is dynamic, as it supports the loading |
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| 393 | # of plugin modules at runtime, so we look up the type |
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| 394 | change_klass = node.attrib['type'] |
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| 395 | change_name = node.attrib['name'] |
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| 396 | |
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| 397 | log.debug("Creating '%s' change", change_klass) |
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| 398 | |
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| 399 | try: |
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| 400 | change_module = sys.modules['change'] |
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| 401 | except KeyError: |
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| 402 | log.info("change module not yet imported. Importing...") |
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| 403 | change_module = __import__('change') |
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| 404 | pass |
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| 405 | |
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| 406 | klass = getattr(change_module, change_klass) |
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| 407 | change = klass(change_name) |
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| 408 | |
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| 409 | log.debug("created change '%s': %s", change_name, change) |
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| 410 | return change |
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| 411 | |
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| 412 | def set_change_namespace(self, change, node): |
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| 413 | """ |
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| 414 | Add a namespace to a change or change template |
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| 415 | """ |
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| 416 | ns = node.find('namespace') |
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| 417 | if ns is None: |
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| 418 | change.namespace = self.global_namespace |
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| 419 | else: |
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| 420 | self.add_namespace(ns, change) |
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| 421 | |
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| 422 | def set_change_provisioner(self, change, node): |
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| 423 | # which provisioner to use for the change |
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| 424 | try: |
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| 425 | provname = node.attrib['provisioner'] |
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| 426 | except KeyError: |
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| 427 | return |
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| 428 | |
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| 429 | provname = util.substituteVariables(provname, change.namespace) |
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| 430 | try: |
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| 431 | change.provisioner = self.provisioners[provname] |
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| 432 | log.debug("change '%s' will use provisioner '%s'", change, provname) |
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| 433 | except KeyError: |
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| 434 | raise KeyError("Provisioner named '%s' is not defined" % provname) |
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| 435 | |
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| 436 | def set_change_params(self, change, node): |
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| 437 | """ |
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| 438 | Set common change parameters, defined in subnodes. |
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| 439 | """ |
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| 440 | for subnode in node.xpath('*'): |
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| 441 | # a target device for the change |
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| 442 | if subnode.tag == 'target': |
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| 443 | targetname = subnode.text |
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| 444 | |
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| 445 | # Parse special targetname ALL_TARGETS |
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| 446 | if targetname == 'ALL_TARGETS': |
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| 447 | change.devices.extend( self.devices.values() ) |
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| 448 | devicenames = ','.join( [ '%s' % x for x in self.devices.keys() ] ) |
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| 449 | log.debug("added target devices '%s' for change '%s'", devicenames, change) |
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| 450 | else: |
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| 451 | # perform variable substitution with global namespace |
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| 452 | log.debug("my namespace: %s", change.namespace) |
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| 453 | targetname = util.substituteVariables(targetname, change.namespace) |
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| 454 | dev = self.devices[targetname] |
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| 455 | log.debug("current target list: %s", change.devices) |
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| 456 | change.devices.append(dev) |
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| 457 | log.debug("added target device '%s' for change '%s'", dev, change) |
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| 458 | pass |
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| 459 | |
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| 460 | elif subnode.tag == 'depends': |
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| 461 | changename = subnode.attrib['on'] |
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| 462 | try: |
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| 463 | change.pre_requisites.append(self.changes[changename]) |
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| 464 | except KeyError: |
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| 465 | if changename == change.name: |
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| 466 | log.error("Change '%s' cannot be a pre-requisite of itself.", changename) |
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| 467 | pass |
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| 468 | else: |
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| 469 | log.error("Configuration error: Unknown pre-requisite '%s' for change '%s'", changename, change.name) |
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| 470 | pass |
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| 471 | raise |
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| 472 | log.debug("added change pre-requisite: '%s' for change '%s'", changename, change) |
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| 473 | |
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| 474 | # |
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| 475 | # The following attributes need to be parsed by the change |
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| 476 | # implementation itself, as the permitted contents of the |
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| 477 | # node varies depending on the change type. For example, |
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| 478 | # the implementation actions for a CommandChange are unix-style |
|---|
| 479 | # commandline invokations, while a ZAPIChange might specify |
|---|
| 480 | # NetApp ZAPI documents |
|---|
| 481 | # |
|---|
| 482 | |
|---|
| 483 | # pre-implementation actions for the change |
|---|
| 484 | elif subnode.tag == 'preimpl': |
|---|
| 485 | log.debug("adding change pre-implementation actions") |
|---|
| 486 | change.parse_node_preimpl(subnode) |
|---|
| 487 | |
|---|
| 488 | elif subnode.tag == 'impl': |
|---|
| 489 | log.debug("adding change implementation actions") |
|---|
| 490 | change.parse_node_impl(subnode) |
|---|
| 491 | |
|---|
| 492 | elif subnode.tag == 'postimpl': |
|---|
| 493 | log.debug("adding change post-implementation actions") |
|---|
| 494 | change.parse_node_postimpl(subnode) |
|---|
| 495 | |
|---|
| 496 | elif subnode.tag == 'prebackout': |
|---|
| 497 | log.debug("adding change pre-backout actions") |
|---|
| 498 | change.parse_node_prebackout(subnode) |
|---|
| 499 | |
|---|
| 500 | elif subnode.tag == 'backout': |
|---|
| 501 | log.debug("adding change backout actions") |
|---|
| 502 | change.parse_node_backout(subnode) |
|---|
| 503 | |
|---|
| 504 | elif subnode.tag == 'postbackout': |
|---|
| 505 | log.debug("adding change post-backout actions") |
|---|
| 506 | change.parse_node_postbackout(subnode) |
|---|
| 507 | pass |
|---|
| 508 | pass |
|---|
| 509 | pass |
|---|
| 510 | |
|---|
| 511 | def set_change_iterator(self, change, node): |
|---|
| 512 | """ |
|---|
| 513 | Set an optional change iterator |
|---|
| 514 | """ |
|---|
| 515 | try: |
|---|
| 516 | itername = node.attrib['iterator'] |
|---|
| 517 | except KeyError: |
|---|
| 518 | itername = None |
|---|
| 519 | |
|---|
| 520 | if itername is not None: |
|---|
| 521 | # Use namespace substitution for the itername to allow templating |
|---|
| 522 | itername = util.substituteVariables(itername, change.namespace) |
|---|
| 523 | try: |
|---|
| 524 | change.iterator = self.iterators[itername] |
|---|
| 525 | log.debug("change '%s' will iterate with iterator '%s'" % (change.name, itername)) |
|---|
| 526 | except KeyError: |
|---|
| 527 | log.error("Iterator '%s' is not defined", itername) |
|---|
| 528 | raise |
|---|
| 529 | pass |
|---|
| 530 | pass |
|---|
| 531 | |
|---|
| 532 | def set_change_onfail(self, change, node): |
|---|
| 533 | """ |
|---|
| 534 | Attempt to add an 'onfail' mode for the change, if defined |
|---|
| 535 | """ |
|---|
| 536 | log.debug("Checking for 'onfail' attribute...") |
|---|
| 537 | try: |
|---|
| 538 | onfail = node.attrib['onfail'] |
|---|
| 539 | log.debug("onfail node found.") |
|---|
| 540 | if onfail == 'continue': |
|---|
| 541 | change.on_fail_continue = True |
|---|
| 542 | log.debug("Processing will continue if this change fails") |
|---|
| 543 | |
|---|
| 544 | elif onfail == 'retry': |
|---|
| 545 | change.on_fail_retry = True |
|---|
| 546 | log.debug("This change will retry on failure") |
|---|
| 547 | try: |
|---|
| 548 | max_retries = int(node.attrib['max_retries']) |
|---|
| 549 | change.max_retries = max_retries |
|---|
| 550 | except KeyError: |
|---|
| 551 | pass |
|---|
| 552 | log.debug(" This change will retry at most %d times", change.max_retries) |
|---|
| 553 | except KeyError: |
|---|
| 554 | pass |
|---|
| 555 | |
|---|
| 556 | |
|---|
| 557 | def add_namespace(self, node, item=None): |
|---|
| 558 | """ |
|---|
| 559 | Add a namespace, defined by nsnode, to an item (such as a change) |
|---|
| 560 | This is called within an 'add_' method for the other items, |
|---|
| 561 | such as iterators and changes. |
|---|
| 562 | """ |
|---|
| 563 | ns = Namespace(node.tag) |
|---|
| 564 | |
|---|
| 565 | # Find any parent namespaces |
|---|
| 566 | # FIXME: This is harder in an element tree than if |
|---|
| 567 | # we're building as we go. |
|---|
| 568 | |
|---|
| 569 | # Find namespace entries |
|---|
| 570 | for entry in node.findall('entry'): |
|---|
| 571 | key = entry.attrib['name'] |
|---|
| 572 | value = entry.text |
|---|
| 573 | log.debug("Adding namespace entry: %s -> %s", key, value) |
|---|
| 574 | ns[key] = value |
|---|
| 575 | pass |
|---|
| 576 | |
|---|
| 577 | if item is None: |
|---|
| 578 | # This is the global namespace |
|---|
| 579 | self.global_namespace = ns |
|---|
| 580 | else: |
|---|
| 581 | log.debug("Adding namespace to item: %s", item) |
|---|
| 582 | ns.parent = self.global_namespace |
|---|
| 583 | item.namespace = ns |
|---|
| 584 | |
|---|
| 585 | def get_available_changes(self): |
|---|
| 586 | """ |
|---|
| 587 | This returns a list of pending changes that can be performed, |
|---|
| 588 | either because they have no pre-requsites, or all their |
|---|
| 589 | pre-requisistes have been successfully implemented. |
|---|
| 590 | """ |
|---|
| 591 | changelist = [] |
|---|
| 592 | log.debug("pending changes: %s", self.pending_changes) |
|---|
| 593 | for change in self.pending_changes: |
|---|
| 594 | log.debug("testing change %s", change) |
|---|
| 595 | if len(change.pre_requisites) == 0: |
|---|
| 596 | changelist.append(change) |
|---|
| 597 | log.debug("change '%s' has no pre-reqs. Adding to execution queue.", change) |
|---|
| 598 | continue |
|---|
| 599 | |
|---|
| 600 | else: |
|---|
| 601 | all_prereqs = True |
|---|
| 602 | for prereq in change.pre_requisites: |
|---|
| 603 | log.debug("change '%s' has a pre-req of '%s'", change, prereq) |
|---|
| 604 | if prereq not in self.change_success: |
|---|
| 605 | |
|---|
| 606 | # If we're in backout mode, a prereq in 'backout_ok' state |
|---|
| 607 | # is treated as complete. |
|---|
| 608 | if prereq.state in [ CHANGE_STATE['backout_ok'], ]: |
|---|
| 609 | continue |
|---|
| 610 | |
|---|
| 611 | # If a prereq has failed, doesn't need to retry, and is |
|---|
| 612 | # marked as 'onfail:continue', then we treat it as if |
|---|
| 613 | # this prereq has been met. |
|---|
| 614 | elif prereq.state not in [ CHANGE_STATE['pending'], |
|---|
| 615 | CHANGE_STATE['retry'], |
|---|
| 616 | ] and prereq.on_fail_continue: |
|---|
| 617 | log.debug("prereq failed, but is marked onfail:continue.") |
|---|
| 618 | continue |
|---|
| 619 | |
|---|
| 620 | log.debug("pre-req '%s' not complete yet.", prereq) |
|---|
| 621 | all_prereqs = False |
|---|
| 622 | break |
|---|
| 623 | pass |
|---|
| 624 | |
|---|
| 625 | if all_prereqs: |
|---|
| 626 | log.debug("All pre-reqs for '%s' have completed. Adding to execution queue.", change) |
|---|
| 627 | changelist.append(change) |
|---|
| 628 | else: |
|---|
| 629 | log.debug("change '%s' has pending pre-reqs", change) |
|---|
| 630 | |
|---|
| 631 | log.debug("Returning changelist: %s", changelist) |
|---|
| 632 | return changelist |
|---|
| 633 | |
|---|
| 634 | def change_complete(self, change): |
|---|
| 635 | """ |
|---|
| 636 | Move a change from pending to complete. |
|---|
| 637 | """ |
|---|
| 638 | log.info("Change %s completed.", change.name) |
|---|
| 639 | if change.state == CHANGE_STATE['success']: |
|---|
| 640 | self.change_success.append(change) |
|---|
| 641 | self.pending_changes.remove(change) |
|---|
| 642 | |
|---|
| 643 | elif change.state == CHANGE_STATE['partial_failure']: |
|---|
| 644 | self.change_failure.append(change) |
|---|
| 645 | self.pending_changes.remove(change) |
|---|
| 646 | |
|---|
| 647 | elif change.state == CHANGE_STATE['total_failure']: |
|---|
| 648 | self.change_failure.append(change) |
|---|
| 649 | self.pending_changes.remove(change) |
|---|
| 650 | |
|---|
| 651 | elif change.state == CHANGE_STATE['backout_ok']: |
|---|
| 652 | self.change_failure.append(change) |
|---|
| 653 | self.backout_success.append(change) |
|---|
| 654 | self.pending_changes.remove(change) |
|---|
| 655 | |
|---|
| 656 | elif change.state == CHANGE_STATE['backout_failed']: |
|---|
| 657 | self.change_failure.append(change) |
|---|
| 658 | self.backout_failure.append(change) |
|---|
| 659 | self.pending_changes.remove(change) |
|---|
| 660 | |
|---|
| 661 | elif change.state == CHANGE_STATE['retry']: |
|---|
| 662 | # Change will be retried |
|---|
| 663 | pass |
|---|
| 664 | |
|---|
| 665 | else: |
|---|
| 666 | log.error("Unknown/unhandled change state '%s'", change.state) |
|---|
| 667 | self.pending_changes.remove(change) |
|---|
| 668 | raise ValueError("change_complete() cannot handle change state: %s", change.state) |
|---|
| 669 | |
|---|
| 670 | def _apply_namespace(self, string, namespace): |
|---|
| 671 | """ |
|---|
| 672 | Apply a namespace to a string |
|---|
| 673 | Deprecated |
|---|
| 674 | """ |
|---|
| 675 | if namespace is not None: |
|---|
| 676 | string = string % namespace |
|---|
| 677 | |
|---|
| 678 | return string |
|---|
| 679 | |
|---|
| 680 | def process_dependencies(self): |
|---|
| 681 | """ |
|---|
| 682 | Post-process the dependency tree after loading it. |
|---|
| 683 | This sets up the pre-reqs for each change, as specified |
|---|
| 684 | in the dependency tree. |
|---|
| 685 | """ |
|---|
| 686 | # Fetch the list of changes with dependencies |
|---|
| 687 | for node in self.tree.findall('dependencies'): |
|---|
| 688 | log.debug("dependency node: %s", node) |
|---|
| 689 | |
|---|
| 690 | class ChangeController: |
|---|
| 691 | """ |
|---|
| 692 | An overall change controller, to control the changes |
|---|
| 693 | """ |
|---|
| 694 | |
|---|
| 695 | def __init__(self, config_loader): |
|---|
| 696 | |
|---|
| 697 | self.cfgldr = config_loader |
|---|
| 698 | |
|---|
| 699 | self.current_changelist = [] |
|---|
| 700 | |
|---|
| 701 | def do_changes(self): |
|---|
| 702 | self.alldone = defer.Deferred() |
|---|
| 703 | |
|---|
| 704 | self.get_next_changes(None) |
|---|
| 705 | |
|---|
| 706 | # print statistics for what happened, no matter if it's callback or errback |
|---|
| 707 | self.alldone.addCallbacks(self.print_stats, self.print_stats) |
|---|
| 708 | |
|---|
| 709 | # deal with errors in stats |
|---|
| 710 | #self.alldone.addErrback(self.print_stats) |
|---|
| 711 | |
|---|
| 712 | return self.alldone |
|---|
| 713 | |
|---|
| 714 | def get_next_changes(self, results): |
|---|
| 715 | """ |
|---|
| 716 | Fetch the next set of changes to run. |
|---|
| 717 | This collects all changes that don't have any |
|---|
| 718 | pre-requisites (on the first pass), or that have had all |
|---|
| 719 | their pre-requisites complete successfully. |
|---|
| 720 | These changes can therefore all be run together, since they |
|---|
| 721 | have no interdependencies on one another. |
|---|
| 722 | """ |
|---|
| 723 | log.debug("Results in get_next_changes are: %s", results) |
|---|
| 724 | log.debug("Fetching outstanding changes...") |
|---|
| 725 | self.current_changelist = self.cfgldr.get_available_changes() |
|---|
| 726 | |
|---|
| 727 | if len(self.current_changelist) == 0: |
|---|
| 728 | if len(self.cfgldr.pending_changes) > 0: |
|---|
| 729 | log.error("Pending changes exist that cannot be executed!") |
|---|
| 730 | self.alldone.errback(ValueError("Pending changes cannot be executed")) |
|---|
| 731 | else: |
|---|
| 732 | # No more changes, all changes completed. |
|---|
| 733 | self.alldone.callback("All changes complete") |
|---|
| 734 | pass |
|---|
| 735 | else: |
|---|
| 736 | # If there are pending changes, add that call to the deferred |
|---|
| 737 | log.debug("Pending changes to be executed. Scheduling.") |
|---|
| 738 | return self.do_pending_changes(None) |
|---|
| 739 | |
|---|
| 740 | def do_pending_changes(self, ignored): |
|---|
| 741 | """ |
|---|
| 742 | This runs all the pending changes that are currently queued. |
|---|
| 743 | It runs all of them simultaneously, since they have been identified |
|---|
| 744 | as changes that can be run together. If you want to run changes |
|---|
| 745 | sequentially, then they should have sequential dependencies. |
|---|
| 746 | """ |
|---|
| 747 | log.debug("Running pending changes...") |
|---|
| 748 | dlist = [] |
|---|
| 749 | |
|---|
| 750 | log.debug("changelist is: %s", self.current_changelist) |
|---|
| 751 | for change in self.current_changelist: |
|---|
| 752 | |
|---|
| 753 | log.debug("adding change '%s' to implementation queue", change.name) |
|---|
| 754 | |
|---|
| 755 | d = change.provisioner.perform_change(None, change, self.cfgldr.global_namespace, backout=self.cfgldr.options.backout) |
|---|
| 756 | d.addCallback(self.change_complete, change) |
|---|
| 757 | d.addErrback(self.change_failure, change) |
|---|
| 758 | dlist.append(d) |
|---|
| 759 | pass |
|---|
| 760 | |
|---|
| 761 | dl = defer.DeferredList(dlist, fireOnOneErrback=True, consumeErrors=True) |
|---|
| 762 | # After the current crop of changes has been completed, find if there are more |
|---|
| 763 | dl.addCallback( self.get_next_changes ) |
|---|
| 764 | dl.addErrback( self.bailout ) |
|---|
| 765 | return dl |
|---|
| 766 | |
|---|
| 767 | def bailout(self, failure): |
|---|
| 768 | """ |
|---|
| 769 | Bailout detects the first error from the deferred list, |
|---|
| 770 | and bails out. |
|---|
| 771 | """ |
|---|
| 772 | log.debug("Running bailout...") |
|---|
| 773 | if failure.value.subFailure.type == UserBailout: |
|---|
| 774 | self.alldone.callback('Bailout') |
|---|
| 775 | |
|---|
| 776 | else: |
|---|
| 777 | log.debug("Unhandled failure: %s", failure) |
|---|
| 778 | self.alldone.errback(failure) |
|---|
| 779 | |
|---|
| 780 | def change_complete(self, ignored, change): |
|---|
| 781 | """ |
|---|
| 782 | Move change from pending to complete |
|---|
| 783 | """ |
|---|
| 784 | self.cfgldr.change_complete(change) |
|---|
| 785 | |
|---|
| 786 | def change_failure(self, failure, change): |
|---|
| 787 | if failure.type == UserBailout: |
|---|
| 788 | log.debug("Controller detected UserBailout.") |
|---|
| 789 | return failure |
|---|
| 790 | |
|---|
| 791 | elif failure.type == ChangeConditionFailure: |
|---|
| 792 | pass |
|---|
| 793 | |
|---|
| 794 | else: |
|---|
| 795 | log.error("Major change failure!") |
|---|
| 796 | tlog.err(failure) |
|---|
| 797 | pass |
|---|
| 798 | |
|---|
| 799 | self.change_complete(failure, change) |
|---|
| 800 | |
|---|
| 801 | def print_stats(self, ignored): |
|---|
| 802 | """ |
|---|
| 803 | We've finished all our work, and now we summarise what happened. |
|---|
| 804 | """ |
|---|
| 805 | success_count = len(self.cfgldr.change_success) |
|---|
| 806 | failure_count = len(self.cfgldr.change_failure) |
|---|
| 807 | backout_success_count = len(self.cfgldr.backout_success) |
|---|
| 808 | backout_failure_count = len(self.cfgldr.backout_failure) |
|---|
| 809 | pending_count = len(self.cfgldr.pending_changes) |
|---|
| 810 | |
|---|
| 811 | log.info("--- Final results ---") |
|---|
| 812 | |
|---|
| 813 | # Don't print some stats when in backout mode |
|---|
| 814 | if not self.cfgldr.options.backout: |
|---|
| 815 | |
|---|
| 816 | if not (success_count > 0 or failure_count > 0): |
|---|
| 817 | log.error("no changes succeeded or failed!") |
|---|
| 818 | else: |
|---|
| 819 | log.info("%d ok, %d failed (%d%% success rate)" % (success_count, failure_count, 100 * success_count / (success_count+failure_count) ) ) |
|---|
| 820 | |
|---|
| 821 | if success_count > 0: |
|---|
| 822 | log.info( "Successful changes: %s" % ', '.join([ x.name for x in self.cfgldr.change_success])) |
|---|
| 823 | |
|---|
| 824 | if failure_count > 0: |
|---|
| 825 | log.info( "Failed changes: %s" % ', '.join([ x.name for x in self.cfgldr.change_failure]) ) |
|---|
| 826 | pass |
|---|
| 827 | pass |
|---|
| 828 | |
|---|
| 829 | # These stats are always printed |
|---|
| 830 | |
|---|
| 831 | if backout_success_count > 0 or backout_failure_count > 0: |
|---|
| 832 | log.info( "%d backed out ok, %d failed (%d%% backout success rate)" % (backout_success_count, backout_failure_count, 100 * backout_success_count / (backout_success_count+backout_failure_count) )) |
|---|
| 833 | |
|---|
| 834 | if backout_success_count > 0: |
|---|
| 835 | log.info( "Changes backed out ok: %s" % ', '.join([ x.name for x in self.cfgldr.backout_success])) |
|---|
| 836 | |
|---|
| 837 | if backout_failure_count > 0: |
|---|
| 838 | log.error( "Changes NOT backed out ok: %s" % ', '.join([ x.name for x in self.cfgldr.backout_failure])) |
|---|
| 839 | |
|---|
| 840 | if pending_count > 0: |
|---|
| 841 | if pending_count > 1: |
|---|
| 842 | plural = 's' |
|---|
| 843 | waswere = 'were' |
|---|
| 844 | else: |
|---|
| 845 | plural = '' |
|---|
| 846 | waswere = 'was' |
|---|
| 847 | pass |
|---|
| 848 | |
|---|
| 849 | log.info( "%d change%s %s not attempted: %s" % (pending_count, plural, waswere, ', '.join([ x.name for x in self.cfgldr.pending_changes ]) ) ) |
|---|
| 850 | |
|---|
| 851 | |
|---|
| 852 | if __name__ == '__main__': |
|---|
| 853 | |
|---|
| 854 | #log.setLevel(logging.DEBUG) |
|---|
| 855 | log.setLevel(logging.INFO) |
|---|
| 856 | |
|---|
| 857 | configfile = 'etc/test_change.conf' |
|---|
| 858 | |
|---|
| 859 | try: |
|---|
| 860 | cfgldr = ConfigLoader(configfile) |
|---|
| 861 | except: |
|---|
| 862 | log.error("Cannot load configuration. Aborting.") |
|---|
| 863 | sys.exit(1) |
|---|
| 864 | |
|---|
| 865 | log.debug("changes to apply: %s", cfgldr.changes) |
|---|
| 866 | log.debug("total devices: %s", cfgldr.devices) |
|---|
| 867 | |
|---|
| 868 | controller = ChangeController(cfgldr) |
|---|
| 869 | |
|---|
| 870 | def mystop(ignored): |
|---|
| 871 | log.debug("finished!") |
|---|
| 872 | reactor.stop() |
|---|
| 873 | pass |
|---|
| 874 | |
|---|
| 875 | def errstop(failure): |
|---|
| 876 | log.error("Changes not implemented ok!") |
|---|
| 877 | tlog.err(failure) |
|---|
| 878 | reactor.stop() |
|---|
| 879 | |
|---|
| 880 | def go(): |
|---|
| 881 | d = controller.do_changes() |
|---|
| 882 | d.addCallbacks(mystop, errstop) |
|---|
| 883 | |
|---|
| 884 | # Use callLater(0) syntax to trigger running of changes once |
|---|
| 885 | # the reactor has actually started, so it can be stopped cleanly. |
|---|
| 886 | reactor.callLater(0, go) |
|---|
| 887 | reactor.run() |
|---|
| 888 | |
|---|
