Move built-in functions to separate modules

partial-blueprint function-plugins

Change-Id: I6ee08f962935c07d292ab4f3f298fbb5e5176e8f

heat/engine/cfn/functions.py

@@ -0,0 +1,567 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import collections
+import json
+
+from heat.api.aws import utils as aws_utils
+from heat.common import exception
+
+from heat.engine import function
+
+
+class FindInMap(function.Function):
+    '''
+    A function for resolving keys in the template mappings.
+
+    Takes the form::
+
+        { "Fn::FindInMap" : [ "mapping",
+                              "key",
+                              "value" ] }
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(FindInMap, self).__init__(stack, fn_name, args)
+
+        try:
+            self._mapname, self._mapkey, self._mapvalue = self.args
+        except ValueError as ex:
+            raise KeyError(str(ex))
+
+    def result(self):
+        mapping = self.stack.t.maps[function.resolve(self._mapname)]
+        key = function.resolve(self._mapkey)
+        value = function.resolve(self._mapvalue)
+        return mapping[key][value]
+
+
+class GetAZs(function.Function):
+    '''
+    A function for retrieving the availability zones.
+
+    Takes the form::
+
+        { "Fn::GetAZs" : "<region>" }
+    '''
+
+    def result(self):
+        # TODO(therve): Implement region scoping
+        #region = function.resolve(self.args)
+
+        if self.stack is None:
+            return ['nova']
+        else:
+            return self.stack.get_availability_zones()
+
+
+class ParamRef(function.Function):
+    '''
+    A function for resolving parameter references.
+
+    Takes the form::
+
+        { "Ref" : "<param_name>" }
+    '''
+
+    def result(self):
+        param_name = function.resolve(self.args)
+
+        try:
+            return self.stack.parameters[param_name]
+        except (KeyError, ValueError):
+            raise exception.UserParameterMissing(key=param_name)
+
+
+class ResourceRef(function.Function):
+    '''
+    A function for resolving resource references.
+
+    Takes the form::
+
+        { "Ref" : "<resource_name>" }
+    '''
+
+    def _resource(self):
+        resource_name = function.resolve(self.args)
+
+        return self.stack[resource_name]
+
+    def result(self):
+        return self._resource().FnGetRefId()
+
+
+def Ref(stack, fn_name, args):
+    '''
+    A function for resolving parameters or resource references.
+
+    Takes the form::
+
+        { "Ref" : "<param_name>" }
+
+    or::
+
+        { "Ref" : "<resource_name>" }
+    '''
+    if args in stack.t[stack.t.RESOURCES]:
+        RefClass = ResourceRef
+    else:
+        RefClass = ParamRef
+    return RefClass(stack, fn_name, args)
+
+
+class GetAtt(function.Function):
+    '''
+    A function for resolving resource attributes.
+
+    Takes the form::
+
+        { "Fn::GetAtt" : [ "<resource_name>",
+                           "<attribute_name" ] }
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(GetAtt, self).__init__(stack, fn_name, args)
+
+        self._resource_name, self._attribute = self._parse_args()
+
+    def _parse_args(self):
+        try:
+            resource_name, attribute = self.args
+        except ValueError:
+            raise ValueError(_('Arguments to "%s" must be of the form '
+                               '[resource_name, attribute]') % self.fn_name)
+
+        return resource_name, attribute
+
+    def _resource(self):
+        resource_name = function.resolve(self._resource_name)
+
+        try:
+            return self.stack[resource_name]
+        except KeyError:
+            raise exception.InvalidTemplateAttribute(
+                resource=resource_name,
+                key=function.resolve(self._attribute))
+
+    def result(self):
+        attribute = function.resolve(self._attribute)
+
+        r = self._resource()
+        if (r.status in (r.IN_PROGRESS, r.COMPLETE) and
+                r.action in (r.CREATE, r.RESUME, r.UPDATE)):
+            return r.FnGetAtt(attribute)
+        else:
+            return None
+
+
+class Select(function.Function):
+    '''
+    A function for selecting an item from a list or map.
+
+    Takes the form (for a list lookup)::
+
+        { "Fn::Select" : [ "<index>", [ "<value_1>", "<value_2>", ... ] ] }
+
+    Takes the form (for a map lookup)::
+
+        { "Fn::Select" : [ "<index>", { "<key_1>": "<value_1>", ... } ] }
+
+    If the selected index is not found, this function resolves to an empty
+    string.
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(Select, self).__init__(stack, fn_name, args)
+
+        try:
+            self._lookup, self._strings = self.args
+        except ValueError:
+            raise ValueError(_('Arguments to "%s" must be of the form '
+                               '[index, collection]') % self.fn_name)
+
+    def result(self):
+        index = function.resolve(self._lookup)
+
+        try:
+            index = int(index)
+        except (ValueError, TypeError):
+            pass
+
+        strings = function.resolve(self._strings)
+
+        if strings == '':
+            # an empty string is a common response from other
+            # functions when result is not currently available.
+            # Handle by returning an empty string
+            return ''
+
+        if isinstance(strings, basestring):
+            # might be serialized json.
+            try:
+                strings = json.loads(strings)
+            except ValueError as json_ex:
+                fmt_data = {'fn_name': self.fn_name,
+                            'err': json_ex}
+                raise ValueError(_('"%(fn_name)s": %(err)s') % fmt_data)
+
+        if isinstance(strings, collections.Mapping):
+            if not isinstance(index, basestring):
+                raise TypeError(_('Index to "%s" must be a string') %
+                                self.fn_name)
+            return strings.get(index, '')
+
+        if (isinstance(strings, collections.Sequence) and
+                not isinstance(strings, basestring)):
+            if not isinstance(index, (int, long)):
+                raise TypeError(_('Index to "%s" must be an integer') %
+                                self.fn_name)
+
+            try:
+                return strings[index]
+            except IndexError:
+                return ''
+
+        if strings is None:
+            return ''
+
+        raise TypeError(_('Arguments to %s not fully resolved') %
+                        self.fn_name)
+
+
+class Join(function.Function):
+    '''
+    A function for joining strings.
+
+    Takes the form::
+
+        { "Fn::Join" : [ "<delim>", [ "<string_1>", "<string_2>", ... ] }
+
+    And resolves to::
+
+        "<string_1><delim><string_2><delim>..."
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(Join, self).__init__(stack, fn_name, args)
+
+        example = '"%s" : [ " ", [ "str1", "str2"]]' % self.fn_name
+        fmt_data = {'fn_name': self.fn_name,
+                    'example': example}
+
+        if isinstance(self.args, (basestring, collections.Mapping)):
+            raise TypeError(_('Incorrect arguments to "%(fn_name)s" '
+                              'should be: %(example)s') % fmt_data)
+
+        try:
+            self._delim, self._strings = self.args
+        except ValueError:
+            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
+                               'should be: %(example)s') % fmt_data)
+
+    def result(self):
+        strings = function.resolve(self._strings)
+        if (isinstance(strings, basestring) or
+                not isinstance(strings, collections.Sequence)):
+            raise TypeError(_('"%s" must operate on a list') % self.fn_name)
+
+        delim = function.resolve(self._delim)
+        if not isinstance(delim, basestring):
+            raise TypeError(_('"%s" delimiter must be a string') %
+                            self.fn_name)
+
+        def ensure_string(s):
+            if s is None:
+                return ''
+            if not isinstance(s, basestring):
+                raise TypeError(_('Items to join must be strings'))
+            return s
+
+        return delim.join(ensure_string(s) for s in strings)
+
+
+class Split(function.Function):
+    '''
+    A function for splitting strings.
+
+    Takes the form::
+
+        { "Fn::Split" : [ "<delim>", "<string_1><delim><string_2>..." ] }
+
+    And resolves to::
+
+        [ "<string_1>", "<string_2>", ... ]
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(Split, self).__init__(stack, fn_name, args)
+
+        example = '"%s" : [ ",", "str1,str2"]]' % self.fn_name
+        fmt_data = {'fn_name': self.fn_name,
+                    'example': example}
+
+        if isinstance(self.args, (basestring, collections.Mapping)):
+            raise TypeError(_('Incorrect arguments to "%(fn_name)s" '
+                              'should be: %(example)s') % fmt_data)
+
+        try:
+            self._delim, self._strings = self.args
+        except ValueError:
+            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
+                               'should be: %(example)s') % fmt_data)
+
+    def result(self):
+        strings = function.resolve(self._strings)
+
+        if not isinstance(self._delim, basestring):
+            raise TypeError(_("Delimiter for %s must be string") %
+                            self.fn_name)
+        if not isinstance(strings, basestring):
+            raise TypeError(_("String to split must be string; got %s") %
+                            type(strings))
+
+        return strings.split(self._delim)
+
+
+class Replace(function.Function):
+    '''
+    A function for performing string subsitutions.
+
+    Takes the form::
+
+        { "Fn::Replace" : [
+            { "<key_1>": "<value_1>", "<key_2>": "<value_2>", ... },
+            "<key_1> <key_2>"
+          ] }
+
+    And resolves to::
+
+        "<value_1> <value_2>"
+
+    This is implemented using python str.replace on each key. The order in
+    which replacements are performed is undefined.
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(Replace, self).__init__(stack, fn_name, args)
+
+        self._mapping, self._string = self._parse_args()
+
+        if not isinstance(self._mapping, collections.Mapping):
+            raise TypeError(_('"%s" parameters must be a mapping') %
+                            self.fn_name)
+
+    def _parse_args(self):
+
+        example = ('{"%s": '
+                   '[ {"$var1": "foo", "%%var2%%": "bar"}, '
+                   '"$var1 is %%var2%%"]}' % self.fn_name)
+        fmt_data = {'fn_name': self.fn_name,
+                    'example': example}
+
+        if isinstance(self.args, (basestring, collections.Mapping)):
+            raise TypeError(_('Incorrect arguments to "%(fn_name)s" '
+                              'should be: %(example)s') % fmt_data)
+
+        try:
+            mapping, string = self.args
+        except ValueError:
+            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
+                               'should be: %(example)s') % fmt_data)
+        else:
+            return mapping, string
+
+    def result(self):
+        template = function.resolve(self._string)
+        mapping = function.resolve(self._mapping)
+
+        if not isinstance(template, basestring):
+            raise TypeError(_('"%s" template must be a string') % self.fn_name)
+
+        if not isinstance(mapping, collections.Mapping):
+            raise TypeError(_('"%s" params must be a map') % self.fn_name)
+
+        def replace(string, change):
+            placeholder, value = change
+
+            if not isinstance(placeholder, basestring):
+                raise TypeError(_('"%s" param placeholders must be strings') %
+                                self.fn_name)
+
+            if value is None:
+                value = ''
+
+            if not isinstance(value, (basestring, int, long, float, bool)):
+                raise TypeError(_('"%s" params must be strings or numbers') %
+                                self.fn_name)
+
+            return string.replace(placeholder, unicode(value))
+
+        return reduce(replace, mapping.iteritems(), template)
+
+
+class Base64(function.Function):
+    '''
+    A placeholder function for converting to base64.
+
+    Takes the form::
+
+        { "Fn::Base64" : "<string>" }
+
+    This function actually performs no conversion. It is included for the
+    benefit of templates that convert UserData to Base64. Heat accepts UserData
+    in plain text.
+    '''
+
+    def result(self):
+        resolved = function.resolve(self.args)
+        if not isinstance(resolved, basestring):
+            raise TypeError(_('"%s" argument must be a string') % self.fn_name)
+        return resolved
+
+
+class MemberListToMap(function.Function):
+    '''
+    A function for converting lists containing enumerated keys and values to
+    a mapping.
+
+    Takes the form::
+
+        { 'Fn::MemberListToMap' : [ 'Name',
+                                    'Value',
+                                    [ '.member.0.Name=<key_0>',
+                                      '.member.0.Value=<value_0>',
+                                      ... ] ] }
+
+    And resolves to::
+
+        { "<key_0>" : "<value_0>", ... }
+
+    The first two arguments are the names of the key and value.
+    '''
+
+    def __init__(self, stack, fn_name, args):
+        super(MemberListToMap, self).__init__(stack, fn_name, args)
+
+        try:
+            self._keyname, self._valuename, self._list = self.args
+        except ValueError:
+            correct = '''
+            {'Fn::MemberListToMap': ['Name', 'Value',
+                                     ['.member.0.Name=key',
+                                      '.member.0.Value=door']]}
+            '''
+            raise TypeError(_('Wrong Arguments try: "%s"') % correct)
+
+        if not isinstance(self._keyname, basestring):
+            raise TypeError(_('%s Key Name must be a string') % self.fn_name)
+
+        if not isinstance(self._valuename, basestring):
+            raise TypeError(_('%s Value Name must be a string') % self.fn_name)
+
+    def result(self):
+        member_list = function.resolve(self._list)
+
+        if not isinstance(member_list, collections.Iterable):
+            raise TypeError(_('Member list must be a list'))
+
+        def item(s):
+            if not isinstance(s, basestring):
+                raise TypeError(_("Member list items must be strings"))
+            return s.split('=', 1)
+
+        partials = dict(item(s) for s in member_list)
+        return aws_utils.extract_param_pairs(partials,
+                                             prefix='',
+                                             keyname=self._keyname,
+                                             valuename=self._valuename)
+
+
+class ResourceFacade(function.Function):
+    '''
+    A function for obtaining data from the facade resource from within the
+    corresponding provider template.
+
+    Takes the form::
+
+        { "Fn::ResourceFacade": "<attribute_type>" }
+
+    where the valid attribute types are "Metadata", "DeletionPolicy" and
+    "UpdatePolicy".
+    '''
+
+    _RESOURCE_ATTRIBUTES = (
+        METADATA, DELETION_POLICY, UPDATE_POLICY,
+    ) = (
+        'Metadata', 'DeletionPolicy', 'UpdatePolicy'
+    )
+
+    def __init__(self, stack, fn_name, args):
+        super(ResourceFacade, self).__init__(stack, fn_name, args)
+
+        if self.args not in self._RESOURCE_ATTRIBUTES:
+            fmt_data = {'fn_name': self.fn_name,
+                        'allowed': ', '.join(self._RESOURCE_ATTRIBUTES)}
+            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
+                               'should be one of: %(allowed)s') % fmt_data)
+
+    def result(self):
+        attr = function.resolve(self.args)
+
+        if attr == self.METADATA:
+            return self.stack.parent_resource.metadata
+        elif attr == self.UPDATE_POLICY:
+            return self.stack.parent_resource.t.get(attr, {})
+        elif attr == self.DELETION_POLICY:
+            try:
+                return self.stack.parent_resource.t[attr]
+            except KeyError:
+                # TODO(zaneb): This should have a default!
+                fmt_data = {'fn_name': self.fn_name,
+                            'key': attr}
+                raise KeyError(_('"%(fn_name)s" '
+                                 'key "%(key)s" not found') % fmt_data)
+
+
+def function_mapping(version_key, version):
+    if version_key == 'AWSTemplateFormatVersion':
+        return {
+            'Fn::FindInMap': FindInMap,
+            'Fn::GetAZs': GetAZs,
+            'Ref': Ref,
+            'Fn::GetAtt': GetAtt,
+            'Fn::Select': Select,
+            'Fn::Join': Join,
+            'Fn::Base64': Base64,
+        }
+    elif version_key != 'HeatTemplateFormatVersion':
+        return {}
+
+    if version == '2012-12-12':
+        return {
+            'Fn::FindInMap': FindInMap,
+            'Fn::GetAZs': GetAZs,
+            'Ref': Ref,
+            'Fn::GetAtt': GetAtt,
+            'Fn::Select': Select,
+            'Fn::Join': Join,
+            'Fn::Split': Split,
+            'Fn::Replace': Replace,
+            'Fn::Base64': Base64,
+            'Fn::MemberListToMap': MemberListToMap,
+            'Fn::ResourceFacade': ResourceFacade,
+        }
+
+    return {}

heat/engine/hot/__init__.py

@@ -12,10 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import collections
-
 from heat.common import exception
-from heat.engine import function
 from heat.engine import template
 from heat.engine import parameters
 from heat.engine import constraints as constr
@@ -154,202 +151,8 @@ class HOTemplate(template.Template):
                              validate_value=validate_value, context=context)
 
     def functions(self):
-        return {
+        from heat.engine.hot import functions
-            'Fn::FindInMap': template.FindInMap,
+        return functions.function_mapping(*self.version())
-            'Fn::GetAZs': template.GetAZs,
-            'get_param': GetParam,
-            'get_resource': template.ResourceRef,
-            'Ref': template.Ref,
-            'get_attr': GetAtt,
-            'Fn::Select': template.Select,
-            'Fn::Join': template.Join,
-            'Fn::Split': template.Split,
-            'str_replace': Replace,
-            'Fn::Replace': template.Replace,
-            'Fn::Base64': template.Base64,
-            'Fn::MemberListToMap': template.MemberListToMap,
-            'Fn::ResourceFacade': template.ResourceFacade,
-            'get_file': GetFile,
-        }
-
-
-class GetParam(function.Function):
-    '''
-    A function for resolving parameter references.
-
-    Takes the form::
-
-        get_param: <param_name>
-
-    or::
-
-        get_param:
-          - <param_name>
-          - <path1>
-          - ...
-    '''
-
-    def result(self):
-        args = function.resolve(self.args)
-
-        if not args:
-            raise ValueError(_('Function "%s" must have arguments') %
-                             self.fn_name)
-
-        if isinstance(args, basestring):
-            param_name = args
-            path_components = []
-        elif isinstance(args, collections.Sequence):
-            param_name = args[0]
-            path_components = args[1:]
-        else:
-            raise TypeError(_('Argument to "%s" must be string or list') %
-                            self.fn_name)
-
-        if not isinstance(param_name, basestring):
-            raise TypeError(_('Parameter name in "%s" must be string') %
-                            self.fn_name)
-
-        try:
-            parameter = self.stack.parameters[param_name]
-        except KeyError:
-            raise exception.UserParameterMissing(key=param_name)
-
-        def get_path_component(collection, key):
-            if not isinstance(collection, (collections.Mapping,
-                                           collections.Sequence)):
-                raise TypeError(_('"%s" can\'t traverse path') % self.fn_name)
-
-            if not isinstance(key, (basestring, int)):
-                raise TypeError(_('Path components in "%s" '
-                                  'must be strings') % self.fn_name)
-
-            return collection[key]
-
-        try:
-            return reduce(get_path_component, path_components, parameter)
-        except (KeyError, IndexError, TypeError):
-            return ''
-
-
-class GetAtt(template.GetAtt):
-    '''
-    A function for resolving resource attributes.
-
-    Takes the form::
-
-        get_attr:
-          - <resource_name>
-          - <attribute_name>
-          - <path1>
-          - ...
-    '''
-
-    def _parse_args(self):
-        if (not isinstance(self.args, collections.Sequence) or
-                isinstance(self.args, basestring)):
-            raise TypeError(_('Argument to "%s" must be a list') %
-                            self.fn_name)
-
-        if len(self.args) < 2:
-            raise ValueError(_('Arguments to "%s" must be of the form '
-                               '[resource_name, attribute, (path), ...]') %
-                             self.fn_name)
-
-        self._path_components = self.args[2:]
-
-        return tuple(self.args[:2])
-
-    def result(self):
-        attribute = super(GetAtt, self).result()
-        if attribute is None:
-            return ''
-
-        path_components = function.resolve(self._path_components)
-
-        def get_path_component(collection, key):
-            if not isinstance(collection, (collections.Mapping,
-                                           collections.Sequence)):
-                raise TypeError(_('"%s" can\'t traverse path') % self.fn_name)
-
-            if not isinstance(key, (basestring, int)):
-                raise TypeError(_('Path components in "%s" '
-                                  'must be strings') % self.fn_name)
-
-            return collection[key]
-
-        try:
-            return reduce(get_path_component, path_components, attribute)
-        except (KeyError, IndexError, TypeError):
-            return ''
-
-
-class Replace(template.Replace):
-    '''
-    A function for performing string substitutions.
-
-    Takes the form::
-
-        str_replace:
-          template: <key_1> <key_2>
-          params:
-            <key_1>: <value_1>
-            <key_2>: <value_2>
-            ...
-
-    And resolves to::
-
-        "<value_1> <value_2>"
-
-    This is implemented using Python's str.replace on each key. The order in
-    which replacements are performed is undefined.
-    '''
-
-    def _parse_args(self):
-        if not isinstance(self.args, collections.Mapping):
-            raise TypeError(_('Arguments to "%s" must be a map') %
-                            self.fn_name)
-
-        try:
-            mapping = self.args['params']
-            string = self.args['template']
-        except (KeyError, TypeError):
-            example = ('''str_replace:
-              template: This is var1 template var2
-              params:
-                var1: a
-                var2: string''')
-            raise KeyError(_('"str_replace" syntax should be %s') %
-                           example)
-        else:
-            return mapping, string
-
-
-class GetFile(function.Function):
-    """
-    A function for including a file inline.
-
-    Takes the form::
-
-        get_file: <file_key>
-
-    And resolves to the content stored in the files dictionary under the given
-    key.
-    """
-
-    def result(self):
-        args = function.resolve(self.args)
-        if not (isinstance(args, basestring)):
-            raise TypeError(_('Argument to "%s" must be a string') %
-                            self.fn_name)
-
-        f = self.stack.t.files.get(args)
-        if f is None:
-            fmt_data = {'fn_name': self.fn_name,
-                        'file_key': args}
-            raise ValueError(_('No content found in the "files" section for '
-                               '%(fn_name)s path: %(file_key)s') % fmt_data)
-        return f
 
 
 class HOTParamSchema(parameters.Schema):

heat/engine/hot/functions.py

@@ -0,0 +1,225 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import collections
+
+from heat.common import exception
+
+from heat.engine.cfn import functions as cfn_funcs
+from heat.engine import function
+
+
+class GetParam(function.Function):
+    '''
+    A function for resolving parameter references.
+
+    Takes the form::
+
+        get_param: <param_name>
+
+    or::
+
+        get_param:
+          - <param_name>
+          - <path1>
+          - ...
+    '''
+
+    def result(self):
+        args = function.resolve(self.args)
+
+        if not args:
+            raise ValueError(_('Function "%s" must have arguments') %
+                             self.fn_name)
+
+        if isinstance(args, basestring):
+            param_name = args
+            path_components = []
+        elif isinstance(args, collections.Sequence):
+            param_name = args[0]
+            path_components = args[1:]
+        else:
+            raise TypeError(_('Argument to "%s" must be string or list') %
+                            self.fn_name)
+
+        if not isinstance(param_name, basestring):
+            raise TypeError(_('Parameter name in "%s" must be string') %
+                            self.fn_name)
+
+        try:
+            parameter = self.stack.parameters[param_name]
+        except KeyError:
+            raise exception.UserParameterMissing(key=param_name)
+
+        def get_path_component(collection, key):
+            if not isinstance(collection, (collections.Mapping,
+                                           collections.Sequence)):
+                raise TypeError(_('"%s" can\'t traverse path') % self.fn_name)
+
+            if not isinstance(key, (basestring, int)):
+                raise TypeError(_('Path components in "%s" '
+                                  'must be strings') % self.fn_name)
+
+            return collection[key]
+
+        try:
+            return reduce(get_path_component, path_components, parameter)
+        except (KeyError, IndexError, TypeError):
+            return ''
+
+
+class GetAtt(cfn_funcs.GetAtt):
+    '''
+    A function for resolving resource attributes.
+
+    Takes the form::
+
+        get_attr:
+          - <resource_name>
+          - <attribute_name>
+          - <path1>
+          - ...
+    '''
+
+    def _parse_args(self):
+        if (not isinstance(self.args, collections.Sequence) or
+                isinstance(self.args, basestring)):
+            raise TypeError(_('Argument to "%s" must be a list') %
+                            self.fn_name)
+
+        if len(self.args) < 2:
+            raise ValueError(_('Arguments to "%s" must be of the form '
+                               '[resource_name, attribute, (path), ...]') %
+                             self.fn_name)
+
+        self._path_components = self.args[2:]
+
+        return tuple(self.args[:2])
+
+    def result(self):
+        attribute = super(GetAtt, self).result()
+        if attribute is None:
+            return ''
+
+        path_components = function.resolve(self._path_components)
+
+        def get_path_component(collection, key):
+            if not isinstance(collection, (collections.Mapping,
+                                           collections.Sequence)):
+                raise TypeError(_('"%s" can\'t traverse path') % self.fn_name)
+
+            if not isinstance(key, (basestring, int)):
+                raise TypeError(_('Path components in "%s" '
+                                  'must be strings') % self.fn_name)
+
+            return collection[key]
+
+        try:
+            return reduce(get_path_component, path_components, attribute)
+        except (KeyError, IndexError, TypeError):
+            return ''
+
+
+class Replace(cfn_funcs.Replace):
+    '''
+    A function for performing string substitutions.
+
+    Takes the form::
+
+        str_replace:
+          template: <key_1> <key_2>
+          params:
+            <key_1>: <value_1>
+            <key_2>: <value_2>
+            ...
+
+    And resolves to::
+
+        "<value_1> <value_2>"
+
+    This is implemented using Python's str.replace on each key. The order in
+    which replacements are performed is undefined.
+    '''
+
+    def _parse_args(self):
+        if not isinstance(self.args, collections.Mapping):
+            raise TypeError(_('Arguments to "%s" must be a map') %
+                            self.fn_name)
+
+        try:
+            mapping = self.args['params']
+            string = self.args['template']
+        except (KeyError, TypeError):
+            example = ('''str_replace:
+              template: This is var1 template var2
+              params:
+                var1: a
+                var2: string''')
+            raise KeyError(_('"str_replace" syntax should be %s') %
+                           example)
+        else:
+            return mapping, string
+
+
+class GetFile(function.Function):
+    """
+    A function for including a file inline.
+
+    Takes the form::
+
+        get_file: <file_key>
+
+    And resolves to the content stored in the files dictionary under the given
+    key.
+    """
+
+    def result(self):
+        args = function.resolve(self.args)
+        if not (isinstance(args, basestring)):
+            raise TypeError(_('Argument to "%s" must be a string') %
+                            self.fn_name)
+
+        f = self.stack.t.files.get(args)
+        if f is None:
+            fmt_data = {'fn_name': self.fn_name,
+                        'file_key': args}
+            raise ValueError(_('No content found in the "files" section for '
+                               '%(fn_name)s path: %(file_key)s') % fmt_data)
+        return f
+
+
+def function_mapping(version_key, version):
+    if version_key != 'heat_template_version':
+        return {}
+
+    if version == '2013-05-23':
+        return {
+            'Fn::FindInMap': cfn_funcs.FindInMap,
+            'Fn::GetAZs': cfn_funcs.GetAZs,
+            'get_param': GetParam,
+            'get_resource': cfn_funcs.ResourceRef,
+            'Ref': cfn_funcs.Ref,
+            'get_attr': GetAtt,
+            'Fn::Select': cfn_funcs.Select,
+            'Fn::Join': cfn_funcs.Join,
+            'Fn::Split': cfn_funcs.Split,
+            'str_replace': Replace,
+            'Fn::Replace': cfn_funcs.Replace,
+            'Fn::Base64': cfn_funcs.Base64,
+            'Fn::MemberListToMap': cfn_funcs.MemberListToMap,
+            'Fn::ResourceFacade': cfn_funcs.ResourceFacade,
+            'get_file': GetFile,
+        }
+
+    return {}

heat/engine/template.py

@@ -15,13 +15,10 @@
 
 import collections
 import functools
-import json
 
-from heat.api.aws import utils as aws_utils
 from heat.db import api as db_api
-from heat.common import exception
 from heat.engine import parameters
-from heat.engine import function
+from heat.engine.cfn import functions
 
 
 class Template(collections.Mapping):
@@ -118,32 +115,7 @@ class Template(collections.Mapping):
                                      context=context)
 
     def functions(self):
-        version_key, version = self.version()
+        return functions.function_mapping(*self.version())
-
-        if version_key == self.VERSION:
-            return {
-                'Fn::FindInMap': FindInMap,
-                'Fn::GetAZs': GetAZs,
-                'Ref': Ref,
-                'Fn::GetAtt': GetAtt,
-                'Fn::Select': Select,
-                'Fn::Join': Join,
-                'Fn::Base64': Base64,
-            }
-
-        return {
-            'Fn::FindInMap': FindInMap,
-            'Fn::GetAZs': GetAZs,
-            'Ref': Ref,
-            'Fn::GetAtt': GetAtt,
-            'Fn::Select': Select,
-            'Fn::Join': Join,
-            'Fn::Split': Split,
-            'Fn::Replace': Replace,
-            'Fn::Base64': Base64,
-            'Fn::MemberListToMap': MemberListToMap,
-            'Fn::ResourceFacade': ResourceFacade,
-        }
 
     def parse(self, stack, snippet):
         parse = functools.partial(self.parse, stack)
@@ -160,516 +132,3 @@ class Template(collections.Mapping):
             return [parse(v) for v in snippet]
         else:
             return snippet
-
-
-class FindInMap(function.Function):
-    '''
-    A function for resolving keys in the template mappings.
-
-    Takes the form::
-
-        { "Fn::FindInMap" : [ "mapping",
-                              "key",
-                              "value" ] }
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(FindInMap, self).__init__(stack, fn_name, args)
-
-        try:
-            self._mapname, self._mapkey, self._mapvalue = self.args
-        except ValueError as ex:
-            raise KeyError(str(ex))
-
-    def result(self):
-        mapping = self.stack.t.maps[function.resolve(self._mapname)]
-        key = function.resolve(self._mapkey)
-        value = function.resolve(self._mapvalue)
-        return mapping[key][value]
-
-
-class GetAZs(function.Function):
-    '''
-    A function for retrieving the availability zones.
-
-    Takes the form::
-
-        { "Fn::GetAZs" : "<region>" }
-    '''
-
-    def result(self):
-        # TODO(therve): Implement region scoping
-        #region = function.resolve(self.args)
-
-        if self.stack is None:
-            return ['nova']
-        else:
-            return self.stack.get_availability_zones()
-
-
-class ParamRef(function.Function):
-    '''
-    A function for resolving parameter references.
-
-    Takes the form::
-
-        { "Ref" : "<param_name>" }
-    '''
-
-    def result(self):
-        param_name = function.resolve(self.args)
-
-        try:
-            return self.stack.parameters[param_name]
-        except (KeyError, ValueError):
-            raise exception.UserParameterMissing(key=param_name)
-
-
-class ResourceRef(function.Function):
-    '''
-    A function for resolving resource references.
-
-    Takes the form::
-
-        { "Ref" : "<resource_name>" }
-    '''
-
-    def _resource(self):
-        resource_name = function.resolve(self.args)
-
-        return self.stack[resource_name]
-
-    def result(self):
-        return self._resource().FnGetRefId()
-
-
-def Ref(stack, fn_name, args):
-    '''
-    A function for resolving parameters or resource references.
-
-    Takes the form::
-
-        { "Ref" : "<param_name>" }
-
-    or::
-
-        { "Ref" : "<resource_name>" }
-    '''
-    if args in stack.t[stack.t.RESOURCES]:
-        RefClass = ResourceRef
-    else:
-        RefClass = ParamRef
-    return RefClass(stack, fn_name, args)
-
-
-class GetAtt(function.Function):
-    '''
-    A function for resolving resource attributes.
-
-    Takes the form::
-
-        { "Fn::GetAtt" : [ "<resource_name>",
-                           "<attribute_name" ] }
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(GetAtt, self).__init__(stack, fn_name, args)
-
-        self._resource_name, self._attribute = self._parse_args()
-
-    def _parse_args(self):
-        try:
-            resource_name, attribute = self.args
-        except ValueError:
-            raise ValueError(_('Arguments to "%s" must be of the form '
-                               '[resource_name, attribute]') % self.fn_name)
-
-        return resource_name, attribute
-
-    def _resource(self):
-        resource_name = function.resolve(self._resource_name)
-
-        try:
-            return self.stack[resource_name]
-        except KeyError:
-            raise exception.InvalidTemplateAttribute(
-                resource=resource_name,
-                key=function.resolve(self._attribute))
-
-    def result(self):
-        attribute = function.resolve(self._attribute)
-
-        r = self._resource()
-        if (r.status in (r.IN_PROGRESS, r.COMPLETE) and
-                r.action in (r.CREATE, r.RESUME, r.UPDATE)):
-            return r.FnGetAtt(attribute)
-        else:
-            return None
-
-
-class Select(function.Function):
-    '''
-    A function for selecting an item from a list or map.
-
-    Takes the form (for a list lookup)::
-
-        { "Fn::Select" : [ "<index>", [ "<value_1>", "<value_2>", ... ] ] }
-
-    Takes the form (for a map lookup)::
-
-        { "Fn::Select" : [ "<index>", { "<key_1>": "<value_1>", ... } ] }
-
-    If the selected index is not found, this function resolves to an empty
-    string.
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(Select, self).__init__(stack, fn_name, args)
-
-        try:
-            self._lookup, self._strings = self.args
-        except ValueError:
-            raise ValueError(_('Arguments to "%s" must be of the form '
-                               '[index, collection]') % self.fn_name)
-
-    def result(self):
-        index = function.resolve(self._lookup)
-
-        try:
-            index = int(index)
-        except (ValueError, TypeError):
-            pass
-
-        strings = function.resolve(self._strings)
-
-        if strings == '':
-            # an empty string is a common response from other
-            # functions when result is not currently available.
-            # Handle by returning an empty string
-            return ''
-
-        if isinstance(strings, basestring):
-            # might be serialized json.
-            try:
-                strings = json.loads(strings)
-            except ValueError as json_ex:
-                fmt_data = {'fn_name': self.fn_name,
-                            'err': json_ex}
-                raise ValueError(_('"%(fn_name)s": %(err)s') % fmt_data)
-
-        if isinstance(strings, collections.Mapping):
-            if not isinstance(index, basestring):
-                raise TypeError(_('Index to "%s" must be a string') %
-                                self.fn_name)
-            return strings.get(index, '')
-
-        if (isinstance(strings, collections.Sequence) and
-                not isinstance(strings, basestring)):
-            if not isinstance(index, (int, long)):
-                raise TypeError(_('Index to "%s" must be an integer') %
-                                self.fn_name)
-
-            try:
-                return strings[index]
-            except IndexError:
-                return ''
-
-        if strings is None:
-            return ''
-
-        raise TypeError(_('Arguments to %s not fully resolved') %
-                        self.fn_name)
-
-
-class Join(function.Function):
-    '''
-    A function for joining strings.
-
-    Takes the form::
-
-        { "Fn::Join" : [ "<delim>", [ "<string_1>", "<string_2>", ... ] }
-
-    And resolves to::
-
-        "<string_1><delim><string_2><delim>..."
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(Join, self).__init__(stack, fn_name, args)
-
-        example = '"%s" : [ " ", [ "str1", "str2"]]' % self.fn_name
-        fmt_data = {'fn_name': self.fn_name,
-                    'example': example}
-
-        if isinstance(self.args, (basestring, collections.Mapping)):
-            raise TypeError(_('Incorrect arguments to "%(fn_name)s" '
-                              'should be: %(example)s') % fmt_data)
-
-        try:
-            self._delim, self._strings = self.args
-        except ValueError:
-            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
-                               'should be: %(example)s') % fmt_data)
-
-    def result(self):
-        strings = function.resolve(self._strings)
-        if (isinstance(strings, basestring) or
-                not isinstance(strings, collections.Sequence)):
-            raise TypeError(_('"%s" must operate on a list') % self.fn_name)
-
-        delim = function.resolve(self._delim)
-        if not isinstance(delim, basestring):
-            raise TypeError(_('"%s" delimiter must be a string') %
-                            self.fn_name)
-
-        def ensure_string(s):
-            if s is None:
-                return ''
-            if not isinstance(s, basestring):
-                raise TypeError(_('Items to join must be strings'))
-            return s
-
-        return delim.join(ensure_string(s) for s in strings)
-
-
-class Split(function.Function):
-    '''
-    A function for splitting strings.
-
-    Takes the form::
-
-        { "Fn::Split" : [ "<delim>", "<string_1><delim><string_2>..." ] }
-
-    And resolves to::
-
-        [ "<string_1>", "<string_2>", ... ]
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(Split, self).__init__(stack, fn_name, args)
-
-        example = '"%s" : [ ",", "str1,str2"]]' % self.fn_name
-        fmt_data = {'fn_name': self.fn_name,
-                    'example': example}
-
-        if isinstance(self.args, (basestring, collections.Mapping)):
-            raise TypeError(_('Incorrect arguments to "%(fn_name)s" '
-                              'should be: %(example)s') % fmt_data)
-
-        try:
-            self._delim, self._strings = self.args
-        except ValueError:
-            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
-                               'should be: %(example)s') % fmt_data)
-
-    def result(self):
-        strings = function.resolve(self._strings)
-
-        if not isinstance(self._delim, basestring):
-            raise TypeError(_("Delimiter for %s must be string") %
-                            self.fn_name)
-        if not isinstance(strings, basestring):
-            raise TypeError(_("String to split must be string; got %s") %
-                            type(strings))
-
-        return strings.split(self._delim)
-
-
-class Replace(function.Function):
-    '''
-    A function for performing string subsitutions.
-
-    Takes the form::
-
-        { "Fn::Replace" : [
-            { "<key_1>": "<value_1>", "<key_2>": "<value_2>", ... },
-            "<key_1> <key_2>"
-          ] }
-
-    And resolves to::
-
-        "<value_1> <value_2>"
-
-    This is implemented using python str.replace on each key. The order in
-    which replacements are performed is undefined.
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(Replace, self).__init__(stack, fn_name, args)
-
-        self._mapping, self._string = self._parse_args()
-
-        if not isinstance(self._mapping, collections.Mapping):
-            raise TypeError(_('"%s" parameters must be a mapping') %
-                            self.fn_name)
-
-    def _parse_args(self):
-
-        example = ('{"%s": '
-                   '[ {"$var1": "foo", "%%var2%%": "bar"}, '
-                   '"$var1 is %%var2%%"]}' % self.fn_name)
-        fmt_data = {'fn_name': self.fn_name,
-                    'example': example}
-
-        if isinstance(self.args, (basestring, collections.Mapping)):
-            raise TypeError(_('Incorrect arguments to "%(fn_name)s" '
-                              'should be: %(example)s') % fmt_data)
-
-        try:
-            mapping, string = self.args
-        except ValueError:
-            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
-                               'should be: %(example)s') % fmt_data)
-        else:
-            return mapping, string
-
-    def result(self):
-        template = function.resolve(self._string)
-        mapping = function.resolve(self._mapping)
-
-        if not isinstance(template, basestring):
-            raise TypeError(_('"%s" template must be a string') % self.fn_name)
-
-        if not isinstance(mapping, collections.Mapping):
-            raise TypeError(_('"%s" params must be a map') % self.fn_name)
-
-        def replace(string, change):
-            placeholder, value = change
-
-            if not isinstance(placeholder, basestring):
-                raise TypeError(_('"%s" param placeholders must be strings') %
-                                self.fn_name)
-
-            if value is None:
-                value = ''
-
-            if not isinstance(value, (basestring, int, long, float, bool)):
-                raise TypeError(_('"%s" params must be strings or numbers') %
-                                self.fn_name)
-
-            return string.replace(placeholder, unicode(value))
-
-        return reduce(replace, mapping.iteritems(), template)
-
-
-class Base64(function.Function):
-    '''
-    A placeholder function for converting to base64.
-
-    Takes the form::
-
-        { "Fn::Base64" : "<string>" }
-
-    This function actually performs no conversion. It is included for the
-    benefit of templates that convert UserData to Base64. Heat accepts UserData
-    in plain text.
-    '''
-
-    def result(self):
-        resolved = function.resolve(self.args)
-        if not isinstance(resolved, basestring):
-            raise TypeError(_('"%s" argument must be a string') % self.fn_name)
-        return resolved
-
-
-class MemberListToMap(function.Function):
-    '''
-    A function for converting lists containing enumerated keys and values to
-    a mapping.
-
-    Takes the form::
-
-        { 'Fn::MemberListToMap' : [ 'Name',
-                                    'Value',
-                                    [ '.member.0.Name=<key_0>',
-                                      '.member.0.Value=<value_0>',
-                                      ... ] ] }
-
-    And resolves to::
-
-        { "<key_0>" : "<value_0>", ... }
-
-    The first two arguments are the names of the key and value.
-    '''
-
-    def __init__(self, stack, fn_name, args):
-        super(MemberListToMap, self).__init__(stack, fn_name, args)
-
-        try:
-            self._keyname, self._valuename, self._list = self.args
-        except ValueError:
-            correct = '''
-            {'Fn::MemberListToMap': ['Name', 'Value',
-                                     ['.member.0.Name=key',
-                                      '.member.0.Value=door']]}
-            '''
-            raise TypeError(_('Wrong Arguments try: "%s"') % correct)
-
-        if not isinstance(self._keyname, basestring):
-            raise TypeError(_('%s Key Name must be a string') % self.fn_name)
-
-        if not isinstance(self._valuename, basestring):
-            raise TypeError(_('%s Value Name must be a string') % self.fn_name)
-
-    def result(self):
-        member_list = function.resolve(self._list)
-
-        if not isinstance(member_list, collections.Iterable):
-            raise TypeError(_('Member list must be a list'))
-
-        def item(s):
-            if not isinstance(s, basestring):
-                raise TypeError(_("Member list items must be strings"))
-            return s.split('=', 1)
-
-        partials = dict(item(s) for s in member_list)
-        return aws_utils.extract_param_pairs(partials,
-                                             prefix='',
-                                             keyname=self._keyname,
-                                             valuename=self._valuename)
-
-
-class ResourceFacade(function.Function):
-    '''
-    A function for obtaining data from the facade resource from within the
-    corresponding provider template.
-
-    Takes the form::
-
-        { "Fn::ResourceFacade": "<attribute_type>" }
-
-    where the valid attribute types are "Metadata", "DeletionPolicy" and
-    "UpdatePolicy".
-    '''
-
-    _RESOURCE_ATTRIBUTES = (
-        METADATA, DELETION_POLICY, UPDATE_POLICY,
-    ) = (
-        'Metadata', 'DeletionPolicy', 'UpdatePolicy'
-    )
-
-    def __init__(self, stack, fn_name, args):
-        super(ResourceFacade, self).__init__(stack, fn_name, args)
-
-        if self.args not in self._RESOURCE_ATTRIBUTES:
-            fmt_data = {'fn_name': self.fn_name,
-                        'allowed': ', '.join(self._RESOURCE_ATTRIBUTES)}
-            raise ValueError(_('Incorrect arguments to "%(fn_name)s" '
-                               'should be one of: %(allowed)s') % fmt_data)
-
-    def result(self):
-        attr = function.resolve(self.args)
-
-        if attr == self.METADATA:
-            return self.stack.parent_resource.metadata
-        elif attr == self.UPDATE_POLICY:
-            return self.stack.parent_resource.t.get(attr, {})
-        elif attr == self.DELETION_POLICY:
-            try:
-                return self.stack.parent_resource.t[attr]
-            except KeyError:
-                # TODO(zaneb): This should have a default!
-                fmt_data = {'fn_name': self.fn_name,
-                            'key': attr}
-                raise KeyError(_('"%(fn_name)s" '
-                                 'key "%(key)s" not found') % fmt_data)

heat/tests/test_parser.py

@@ -32,6 +32,8 @@ from heat.engine import parser
 from heat.engine import scheduler
 from heat.engine import template
 
+import heat.engine.cfn.functions
+
 from heat.tests.fakes import FakeKeystoneClient
 from heat.tests.common import HeatTestCase
 from heat.tests import utils
@@ -260,7 +262,7 @@ Mappings:
 
         p_snippet = {"Ref": "baz"}
         parsed = tmpl.parse(stack, p_snippet)
-        self.assertTrue(isinstance(parsed, template.ParamRef))
+        self.assertTrue(isinstance(parsed, heat.engine.cfn.functions.ParamRef))
 
     def test_select_from_list(self):
         tmpl = parser.Template(empty_template)