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Diffstat (limited to 'lookup_plugins/sequence.py')
| -rw-r--r-- | lookup_plugins/sequence.py | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/lookup_plugins/sequence.py b/lookup_plugins/sequence.py new file mode 100644 index 000000000..8ca9e7b39 --- /dev/null +++ b/lookup_plugins/sequence.py @@ -0,0 +1,215 @@ +# (c) 2013, Jayson Vantuyl <jayson@aggressive.ly> +# +# This file is part of Ansible +# +# Ansible is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# Ansible is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with Ansible. If not, see <http://www.gnu.org/licenses/>. + +from ansible.errors import AnsibleError +import ansible.utils as utils +from re import compile as re_compile, IGNORECASE + +# shortcut format +NUM = "(0?x?[0-9a-f]+)" +SHORTCUT = re_compile( + "^(" + # Group 0 + NUM + # Group 1: Start + "-)?" + + NUM + # Group 2: End + "(/" + # Group 3 + NUM + # Group 4: Stride + ")?" + + "(:(.+))?$", # Group 5, Group 6: Format String + IGNORECASE +) + + +class LookupModule(object): + """ + sequence lookup module + + Used to generate some sequence of items. Takes arguments in two forms. + + The simple / shortcut form is: + + [start-]end[/stride][:format] + + As indicated by the brackets: start, stride, and format string are all + optional. The format string is in the style of printf. This can be used + to pad with zeros, format in hexadecimal, etc. All of the numerical values + can be specified in octal (i.e. 0664) or hexadecimal (i.e. 0x3f8). + Negative numbers are not supported. + + Some examples: + + 5 -> ["1","2","3","4","5"] + 5-8 -> ["5", "6", "7", "8"] + 2-10/2 -> ["2", "4", "6", "8", "10"] + 4:host%02d -> ["host01","host02","host03","host04"] + + The standard Ansible key-value form is accepted as well. For example: + + start=5 end=11 stride=2 format=0x%02x -> ["0x05","0x07","0x09","0x0a"] + + This format takes an alternate form of "end" called "count", which counts + some number from the starting value. For example: + + count=5 -> ["1", "2", "3", "4", "5"] + start=0x0f00 count=4 format=%04x -> ["0f00", "0f01", "0f02", "0f03"] + start=0 count=5 stride=2 -> ["0", "2", "4", "6", "8"] + start=1 count=5 stride=2 -> ["1", "3", "5", "7", "9"] + + The count option is mostly useful for avoiding off-by-one errors and errors + calculating the number of entries in a sequence when a stride is specified. + """ + + def __init__(self, basedir, **kwargs): + """absorb any keyword args""" + self.basedir = basedir + + def reset(self): + """set sensible defaults""" + self.start = 1 + self.count = None + self.end = None + self.stride = 1 + self.format = "%d" + + def parse_kv_args(self, args): + """parse key-value style arguments""" + for arg in ["start", "end", "count", "stride"]: + try: + arg_raw = args.pop(arg, None) + if arg_raw is None: + continue + arg_cooked = int(arg_raw, 0) + setattr(self, arg, arg_cooked) + except ValueError: + raise AnsibleError( + "can't parse arg %s=%r as integer" + % (arg, arg_raw) + ) + if 'format' in args: + self.format = args.pop("format") + if args: + raise AnsibleError( + "unrecognized arguments to with_sequence: %r" + % args.keys() + ) + + def parse_simple_args(self, term): + """parse the shortcut forms, return True/False""" + match = SHORTCUT.match(term) + if not match: + return False + + _, start, end, _, stride, _, format = match.groups() + + if start is not None: + try: + start = int(start, 0) + except ValueError: + raise AnsibleError("can't parse start=%s as integer" % start) + if end is not None: + try: + end = int(end, 0) + except ValueError: + raise AnsibleError("can't parse end=%s as integer" % end) + if stride is not None: + try: + stride = int(stride, 0) + except ValueError: + raise AnsibleError("can't parse stride=%s as integer" % stride) + + if start is not None: + self.start = start + if end is not None: + self.end = end + if stride is not None: + self.stride = stride + if format is not None: + self.format = format + + def sanity_check(self): + if self.count is None and self.end is None: + raise AnsibleError( + "must specify count or end in with_sequence" + ) + elif self.count is not None and self.end is not None: + raise AnsibleError( + "can't specify both count and end in with_sequence" + ) + elif self.count is not None: + # convert count to end + if self.count != 0: + self.end = self.start + self.count * self.stride - 1 + else: + self.start = 0 + self.end = 0 + self.stride = 0 + del self.count + if self.stride > 0 and self.end < self.start: + raise AnsibleError("to count backwards make stride negative") + if self.stride < 0 and self.end > self.start: + raise AnsibleError("to count forward don't make stride negative") + if self.format.count('%') != 1: + raise AnsibleError("bad formatting string: %s" % self.format) + + def generate_sequence(self): + if self.stride > 0: + adjust = 1 + else: + adjust = -1 + numbers = xrange(self.start, self.end + adjust, self.stride) + + for i in numbers: + try: + formatted = self.format % i + yield formatted + except (ValueError, TypeError): + raise AnsibleError( + "problem formatting %r with %r" % self.format + ) + + def run(self, terms, inject=None, **kwargs): + results = [] + + terms = utils.listify_lookup_plugin_terms(terms, self.basedir, inject) + + if isinstance(terms, basestring): + terms = [ terms ] + + for term in terms: + try: + self.reset() # clear out things for this iteration + + try: + if not self.parse_simple_args(term): + self.parse_kv_args(utils.parse_kv(term)) + except Exception: + raise AnsibleError( + "unknown error parsing with_sequence arguments: %r" + % term + ) + + self.sanity_check() + if self.stride != 0: + results.extend(self.generate_sequence()) + except AnsibleError: + raise + except Exception, e: + raise AnsibleError( + "unknown error generating sequence: %s" % str(e) + ) + + return results |