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import os
import sys
import yaml
import argparse
class Cfn(object):
base_template = {
'HeatTemplateFormatVersion': '2012-12-12',
'Description': []
}
get_resource = 'Ref'
get_param = 'Ref'
description = 'Description'
parameters = 'Parameters'
outputs = 'Outputs'
resources = 'Resources'
type = 'Type'
properties = 'Properties'
metadata = 'Metadata'
depends_on = 'DependsOn'
get_attr = 'Fn::GetAtt'
class Hot(object):
base_template = {
'heat_template_version': '2013-05-23',
'description': []
}
get_resource = 'get_resource'
get_param = 'get_param'
description = 'description'
parameters = 'parameters'
outputs = 'outputs'
resources = 'resources'
type = 'type'
properties = 'properties'
metadata = 'metadata'
depends_on = 'depends_on'
get_attr = 'get_attr'
lang = Cfn()
def apply_maps(template):
"""Apply Merge::Map within template.
Any dict {'Merge::Map': {'Foo': 'Bar', 'Baz': 'Quux'}}
will resolve to ['Bar', 'Quux'] - that is a dict with key
'Merge::Map' is replaced entirely by that dict['Merge::Map'].values().
"""
if isinstance(template, dict):
if 'Merge::Map' in template:
return sorted(
apply_maps(value) for value in template['Merge::Map'].values()
)
else:
return dict((key, apply_maps(value))
for key, value in template.items())
elif isinstance(template, list):
return [apply_maps(item) for item in template]
else:
return template
def apply_scaling(template, scaling, in_copies=None):
"""Apply a set of scaling operations to template.
This is a single pass recursive function: for each call we process one
dict or list and recurse to handle children containers.
Values are handled via scale_value.
Keys in dicts are copied per the scaling rule.
Values are either replaced or copied depending on whether the given
scaling rule is in in_copies.
in_copies is reset to None when a dict {'Merge::Map': someobject} is
encountered.
:param scaling: A dict of prefix -> (count, blacklists).
"""
in_copies = dict(in_copies or {})
# Shouldn't be needed but to avoid unexpected side effects/bugs we short
# circuit no-ops.
if not scaling:
return template
if isinstance(template, dict):
if 'Merge::Map' in template:
in_copies = None
new_template = {}
for key, value in template.items():
for prefix, copy_num, new_key in scale_value(
key, scaling, in_copies):
if prefix:
# e.g. Compute0, 1, Compute1Foo
in_copies[prefix] = prefix[:-1] + str(copy_num)
if isinstance(value, (dict, list)):
new_value = apply_scaling(value, scaling, in_copies)
new_template[new_key] = new_value
else:
new_values = list(scale_value(value, scaling, in_copies))
# We have nowhere to multiply a non-container value of a
# dict, so it may be copied or unchanged but not scaled.
assert len(new_values) == 1
new_template[new_key] = new_values[0][2]
if prefix:
del in_copies[prefix]
return new_template
elif isinstance(template, list):
new_template = []
for value in template:
if isinstance(value, (dict, list)):
new_template.append(apply_scaling(value, scaling, in_copies))
else:
for _, _, new_value in scale_value(value, scaling, in_copies):
new_template.append(new_value)
return new_template
else:
raise Exception("apply_scaling called with non-container %r" % template)
def scale_value(value, scaling, in_copies):
"""Scale out a value.
:param value: The value to scale (not a container).
:param scaling: The scaling map (prefix-> (copies, blacklist) to use.
:param in_copies: What containers we're currently copying.
:return: An iterator of the new values for the value as tuples:
(prefix, copy_num, value). E.g. Compute0, 1, Compute1Foo
prefix and copy_num are only set when:
- a prefix in scaling matches value
- and that prefix is not in in_copies
"""
if isinstance(value, (str, unicode)):
for prefix, (copies, blacklist) in scaling.items():
if not value.startswith(prefix):
continue
suffix = value[len(prefix):]
if prefix in in_copies:
# Adjust to the copy number we're on
yield None, None, in_copies[prefix] + suffix
return
else:
for n in range(copies):
if n not in blacklist:
yield prefix, n, prefix[:-1] + str(n) + suffix
return
yield None, None, value
else:
yield None, None, value
def parse_scaling(scaling_args):
"""Translate a list of scaling requests to a dict prefix:count."""
scaling_args = scaling_args or []
result = {}
for item in scaling_args:
key, values = item.split('=')
values = values.split(',')
value = int(values[0])
blacklist = frozenset(int(v) for v in values[1:] if v)
result[key + '0'] = value, blacklist
return result
def _translate_role(role, master_role, slave_roles):
if not master_role:
return role
if role == master_role:
return role
if role not in slave_roles:
return role
return master_role
def translate_role(role, master_role, slave_roles):
r = _translate_role(role, master_role, slave_roles)
if not isinstance(r, basestring):
raise Exception('%s -> %r' % (role, r))
return r
def resolve_params(item, param, value):
if item in ({lang.get_param: param}, {lang.get_resource: param}):
return value
if isinstance(item, dict):
copy_item = dict(item)
for k, v in iter(copy_item.items()):
item[k] = resolve_params(v, param, value)
elif isinstance(item, list):
copy_item = list(item)
new_item = []
for v in copy_item:
new_item.append(resolve_params(v, param, value))
item = new_item
return item
MERGABLE_TYPES = {'OS::Nova::Server':
{'image': 'image'},
'AWS::EC2::Instance':
{'image': 'ImageId'},
'AWS::AutoScaling::LaunchConfiguration':
{},
}
INCLUDED_TEMPLATE_DIR = os.getcwd()
def resolve_includes(template, params=None):
new_template = {}
if params is None:
params = {}
for key, value in iter(template.items()):
if key == '__include__':
new_params = dict(params) # do not propagate up the stack
if not isinstance(value, dict):
raise ValueError('__include__ must be a mapping')
if 'path' not in value:
raise ValueError('__include__ must have path')
if 'params' in value:
if not isinstance(value['params'], dict):
raise ValueError('__include__ params must be a mapping')
new_params.update(value['params'])
with open(value['path']) as include_file:
sub_template = yaml.safe_load(include_file.read())
if 'subkey' in value:
if ((not isinstance(value['subkey'], int)
and not isinstance(sub_template, dict))):
raise RuntimeError('subkey requires mapping root or'
' integer for list root')
sub_template = sub_template[value['subkey']]
for k, v in iter(new_params.items()):
sub_template = resolve_params(sub_template, k, v)
new_template.update(resolve_includes(sub_template))
else:
if isinstance(value, dict):
new_template[key] = resolve_includes(value)
else:
new_template[key] = value
return new_template
def main(argv=None):
if argv is None:
argv = sys.argv[1:]
parser = argparse.ArgumentParser()
parser.add_argument('templates', nargs='+')
parser.add_argument('--master-role', nargs='?',
help='Translate slave_roles to this')
parser.add_argument('--slave-roles', nargs='*',
help='Translate all of these to master_role')
parser.add_argument('--included-template-dir', nargs='?',
default=INCLUDED_TEMPLATE_DIR,
help='Path for resolving included templates')
parser.add_argument('--output',
help='File to write output to. - for stdout',
default='-')
parser.add_argument('--scale', action="append",
help="Names to scale out. Pass Prefix=2 to cause a key Prefix0Foo to "
"be copied to Prefix1Foo in the output, and value Prefix0Bar to be"
"renamed to Prefix1Bar inside that copy, or copied to Prefix1Bar "
"outside of any copy. Pass Prefix=3,1 to cause Prefix1* to be elided"
"when scaling Prefix out. Prefix=4,1,2 will likewise elide Prefix1 and"
"Prefix2.")
parser.add_argument(
'--change-image-params', action='store_true', default=False,
help="Change parameters in templates to match resource names. This was "
" the default at one time but it causes issues when parameter "
" names need to remain stable.")
parser.add_argument(
'--hot', action='store_true', default=False,
help="Assume source templates are in the HOT format, and generate a "
"HOT template artifact.")
args = parser.parse_args(argv)
if args.hot:
global lang
lang = Hot()
templates = args.templates
scaling = parse_scaling(args.scale)
merged_template = merge(templates, args.master_role, args.slave_roles,
args.included_template_dir, scaling=scaling,
change_image_params=args.change_image_params)
if args.output == '-':
out_file = sys.stdout
else:
out_file = file(args.output, 'wt')
out_file.write(merged_template)
def merge(templates, master_role=None, slave_roles=None,
included_template_dir=INCLUDED_TEMPLATE_DIR,
scaling=None, change_image_params=None):
scaling = scaling or {}
errors = []
end_template = dict(lang.base_template)
resource_changes=[]
for template_path in templates:
template = yaml.safe_load(open(template_path))
# Resolve __include__ tags
template = resolve_includes(template)
end_template[lang.description].append(template.get(lang.description,
template_path))
new_parameters = template.get(lang.parameters, {})
for p, pbody in sorted(new_parameters.items()):
if p in end_template.get(lang.parameters, {}):
if pbody != end_template[lang.parameters][p]:
errors.append('Parameter %s from %s conflicts.' % (p,
template_path))
continue
if lang.parameters not in end_template:
end_template[lang.parameters] = {}
end_template[lang.parameters][p] = pbody
new_outputs = template.get(lang.outputs, {})
for o, obody in sorted(new_outputs.items()):
if o in end_template.get(lang.outputs, {}):
if pbody != end_template[lang.outputs][p]:
errors.append('Output %s from %s conflicts.' % (o,
template_path))
continue
if lang.outputs not in end_template:
end_template[lang.outputs] = {}
end_template[lang.outputs][o] = obody
new_resources = template.get(lang.resources, {})
for r, rbody in sorted(new_resources.items()):
if rbody[lang.type] in MERGABLE_TYPES:
if change_image_params:
if 'image' in MERGABLE_TYPES[rbody[lang.type]]:
image_key = MERGABLE_TYPES[rbody[lang.type]]['image']
# XXX Assuming ImageId is always a Ref
ikey_val = end_template[lang.parameters][rbody[lang.properties][image_key][lang.get_param]]
del end_template[lang.parameters][rbody[lang.properties][image_key][lang.get_param]]
if 'OpenStack::Role' in rbody.get(lang.metadata, {}):
sys.stderr.write("WARNING: OpenStack::Role is deprecated"
" and will be removed in a later release\n");
role = rbody.get(lang.metadata, {}).get('OpenStack::Role', r)
role = translate_role(role, master_role, slave_roles)
if role != r:
resource_changes.append((r, role))
if role in end_template.get(lang.resources, {}):
new_metadata = rbody.get(lang.metadata, {})
for m, mbody in iter(new_metadata.items()):
if m in end_template[lang.resources][role].get(lang.metadata, {}):
if m == 'OpenStack::ImageBuilder::Elements':
end_template[lang.resources][role][lang.metadata][m].extend(mbody)
sys.stderr.write(
"WARNING: OpenStack::ImageBuilder::Elements"
" is deprecated and will be removed in a"
" later release\n");
continue
if mbody != end_template[lang.resources][role][lang.metadata][m]:
errors.append('Role %s metadata key %s conflicts.' %
(role, m))
continue
role_res = end_template[lang.resources][role]
if role_res[lang.type] == 'OS::Heat::StructuredConfig':
end_template[lang.resources][role][lang.properties]['config'][m] = mbody
else:
end_template[lang.resources][role][lang.metadata][m] = mbody
continue
if lang.resources not in end_template:
end_template[lang.resources] = {}
end_template[lang.resources][role] = rbody
if change_image_params:
if 'image' in MERGABLE_TYPES[rbody[lang.type]]:
ikey = '%sImage' % (role)
end_template[lang.resources][role][lang.properties][image_key] = {lang.get_param: ikey}
end_template[lang.parameters][ikey] = ikey_val
elif rbody[lang.type] == 'FileInclude':
# we trust os.path.join to DTRT: if FileInclude path isn't
# absolute, join to included_template_dir (./)
with open(os.path.join(included_template_dir, rbody['Path'])) as rfile:
include_content = yaml.safe_load(rfile.read())
subkeys = rbody.get('SubKey','').split('.')
while len(subkeys) and subkeys[0]:
include_content = include_content[subkeys.pop(0)]
for replace_param, replace_value in iter(rbody.get(lang.parameters,
{}).items()):
include_content = resolve_params(include_content,
replace_param,
replace_value)
if lang.resources not in end_template:
end_template[lang.resources] = {}
end_template[lang.resources][r] = include_content
else:
if r in end_template.get(lang.resources, {}):
if rbody != end_template[lang.resources][r]:
errors.append('Resource %s from %s conflicts' % (r,
template_path))
continue
if lang.resources not in end_template:
end_template[lang.resources] = {}
end_template[lang.resources][r] = rbody
end_template = apply_scaling(end_template, scaling)
end_template = apply_maps(end_template)
def fix_ref(item, old, new):
if isinstance(item, dict):
copy_item = dict(item)
for k, v in sorted(copy_item.items()):
if k == lang.get_resource and v == old:
item[k] = new
continue
if k == lang.depends_on and v == old:
item[k] = new
continue
if k == lang.get_attr and isinstance(v, list) and v[0] == old:
new_list = list(v)
new_list[0] = new
item[k] = new_list
continue
if k == 'AllowedResources' and isinstance(v, list) and old in v:
while old in v:
pos = v.index(old)
v[pos] = new
continue
fix_ref(v, old, new)
elif isinstance(item, list):
copy_item = list(item)
for v in item:
fix_ref(v, old, new)
for change in resource_changes:
fix_ref(end_template, change[0], change[1])
if errors:
for e in errors:
sys.stderr.write("ERROR: %s\n" % e)
end_template[lang.description] = ','.join(end_template[lang.description])
return yaml.safe_dump(end_template, default_flow_style=False)
if __name__ == "__main__":
main()
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