merge.py

   1 import sys
   2 import yaml
   3 import argparse
   4
   5 parser = argparse.ArgumentParser()
   6 parser.add_argument('templates', nargs='+')
   7 parser.add_argument('--master-role', nargs='?',
   8                     help='Translate slave_roles to this')
   9 parser.add_argument('--slave-roles', nargs='*',
  10                     help='Translate all of these to master_role')
  11
  12 args = parser.parse_args()
  13
  14 templates = args.templates
  15
  16 def _translate_role(role):
  17     global args
  18     if not args.master_role:
  19         return role
  20     if role == args.master_role:
  21         return role
  22     if role not in args.slave_roles:
  23         return role
  24     return args.master_role
  25
  26 def translate_role(role):
  27     r = _translate_role(role)
  28     if not isinstance(r, basestring):
  29         raise Exception('%s -> %r' % (role, r))
  30     return r
  31
  32 def resolve_params(item, param, value):
  33     if item == {'Ref': param}:
  34         return value
  35     if isinstance(item, dict):
  36         copy_item = dict(item)
  37         for k, v in iter(copy_item.items()):
  38             item[k] = resolve_params(v, param, value)
  39     elif isinstance(item, list):
  40         copy_item = list(item)
  41         new_item = []
  42         for v in copy_item:
  43             new_item.append(resolve_params(v, param, value))
  44         item = new_item
  45     return item
  46
  47 MERGABLE_TYPES = {'OS::Nova::Server':
  48                   {'image': 'image'},
  49                   'AWS::EC2::Instance':
  50                   {'image': 'ImageId'},
  51                   'AWS::AutoScaling::LaunchConfiguration':
  52                   {},
  53                  }
  54
  55
  56 def resolve_includes(template, params=None):
  57     new_template = {}
  58     if params is None:
  59         params = {}
  60     for key, value in iter(template.items()):
  61         if key == '__include__':
  62             new_params = dict(params) # do not propagate up the stack
  63             if not isinstance(value, dict):
  64                 raise ValueError('__include__ must be a mapping')
  65             if 'path' not in value:
  66                 raise ValueError('__include__ must have path')
  67             if 'params' in value:
  68                 if not isinstance(value['params'], dict):
  69                     raise ValueError('__include__ params must be a mapping')
  70                 new_params.update(value['params'])
  71             with open(value['path']) as include_file:
  72                 sub_template = yaml.safe_load(include_file.read())
  73                 if 'subkey' in value:
  74                     if ((not isinstance(value['subkey'], int)
  75                          and not isinstance(sub_template, dict))):
  76                         raise RuntimeError('subkey requires mapping root or'
  77                                            ' integer for list root')
  78                     sub_template = sub_template[value['subkey']]
  79                 for k, v in iter(new_params.items()):
  80                     sub_template = resolve_params(sub_template, k, v)
  81                 new_template.update(resolve_includes(sub_template))
  82         else:
  83             if isinstance(value, dict):
  84                 new_template[key] = resolve_includes(value)
  85             else:
  86                 new_template[key] = value
  87     return new_template
  88
  89 errors = []
  90 end_template={'HeatTemplateFormatVersion': '2012-12-12',
  91               'Description': []}
  92 resource_changes=[]
  93 for template_path in templates:
  94     template = yaml.safe_load(open(template_path))
  95     # Resolve __include__ tags
  96     template = resolve_includes(template)
  97     end_template['Description'].append(template.get('Description',
  98                                                     template_path))
  99     new_parameters = template.get('Parameters', {})
 100     for p, pbody in sorted(new_parameters.items()):
 101         if p in end_template.get('Parameters', {}):
 102             if pbody != end_template['Parameters'][p]:
 103                 errors.append('Parameter %s from %s conflicts.' % (p,
 104                                                                    template_path))
 105             continue
 106         if 'Parameters' not in end_template:
 107             end_template['Parameters'] = {}
 108         end_template['Parameters'][p] = pbody
 109
 110     new_outputs = template.get('Outputs', {})
 111     for o, obody in sorted(new_outputs.items()):
 112         if o in end_template.get('Outputs', {}):
 113             if pbody != end_template['Outputs'][p]:
 114                 errors.append('Output %s from %s conflicts.' % (o,
 115                                                                    template_path))
 116             continue
 117         if 'Outputs' not in end_template:
 118             end_template['Outputs'] = {}
 119         end_template['Outputs'][o] = obody
 120
 121     new_resources = template.get('Resources', {})
 122     for r, rbody in sorted(new_resources.items()):
 123         if rbody['Type'] in MERGABLE_TYPES:
 124             if 'image' in MERGABLE_TYPES[rbody['Type']]:
 125                 image_key = MERGABLE_TYPES[rbody['Type']]['image']
 126                 # XXX Assuming ImageId is always a Ref
 127                 ikey_val = end_template['Parameters'][rbody['Properties'][image_key]['Ref']]
 128                 del end_template['Parameters'][rbody['Properties'][image_key]['Ref']]
 129             role = rbody.get('Metadata', {}).get('OpenStack::Role', r)
 130             role = translate_role(role)
 131             if role != r:
 132                 resource_changes.append((r, role))
 133             if role in end_template.get('Resources', {}):
 134                 new_metadata = rbody.get('Metadata', {})
 135                 for m, mbody in iter(new_metadata.items()):
 136                     if m in end_template['Resources'][role].get('Metadata', {}):
 137                         if m == 'OpenStack::ImageBuilder::Elements':
 138                             end_template['Resources'][role]['Metadata'][m].extend(mbody)
 139                             continue
 140                         if mbody != end_template['Resources'][role]['Metadata'][m]:
 141                             errors.append('Role %s metadata key %s conflicts.' %
 142                                           (role, m))
 143                         continue
 144                     end_template['Resources'][role]['Metadata'][m] = mbody
 145                 continue
 146             if 'Resources' not in end_template:
 147                 end_template['Resources'] = {}
 148             end_template['Resources'][role] = rbody
 149             if 'image' in MERGABLE_TYPES[rbody['Type']]:
 150                 ikey = '%sImage' % (role)
 151                 end_template['Resources'][role]['Properties'][image_key] = {'Ref': ikey}
 152                 end_template['Parameters'][ikey] = ikey_val
 153         elif rbody['Type'] == 'FileInclude':
 154             with open(rbody['Path']) as rfile:
 155                 include_content = yaml.safe_load(rfile.read())
 156                 subkeys = rbody.get('SubKey','').split('.')
 157                 while len(subkeys) and subkeys[0]:
 158                     include_content = include_content[subkeys.pop(0)]
 159                 for replace_param, replace_value in iter(rbody.get('Parameters',
 160                                                                    {}).items()):
 161                     include_content = resolve_params(include_content,
 162                                                      replace_param,
 163                                                      replace_value)
 164                 end_template['Resources'][r] = include_content
 165         else:
 166             if r in end_template.get('Resources', {}):
 167                 if rbody != end_template['Resources'][r]:
 168                     errors.append('Resource %s from %s conflicts' % (r,
 169                                                                      template_path))
 170                 continue
 171             if 'Resources' not in end_template:
 172                 end_template['Resources'] = {}
 173             end_template['Resources'][r] = rbody
 174
 175 def fix_ref(item, old, new):
 176     if isinstance(item, dict):
 177         copy_item = dict(item)
 178         for k, v in sorted(copy_item.items()):
 179             if k == 'Ref' and v == old:
 180                 item[k] = new
 181                 continue
 182             if k == 'DependsOn' and v == old:
 183                 item[k] = new
 184                 continue
 185             if k == 'Fn::GetAtt' and isinstance(v, list) and v[0] == old:
 186                 new_list = list(v)
 187                 new_list[0] = new
 188                 item[k] = new_list
 189                 continue
 190             if k == 'AllowedResources' and isinstance(v, list) and old in v:
 191                 while old in v:
 192                     pos = v.index(old)
 193                     v[pos] = new
 194                 continue
 195             fix_ref(v, old, new)
 196     elif isinstance(item, list):
 197         copy_item = list(item)
 198         for v in item:
 199             fix_ref(v, old, new)
 200
 201 for change in resource_changes:
 202     fix_ref(end_template, change[0], change[1])
 203
 204 if errors:
 205     for e in errors:
 206         sys.stderr.write("ERROR: %s\n" % e)
 207 end_template['Description'] = ','.join(end_template['Description'])
 208 sys.stdout.write(yaml.safe_dump(end_template, default_flow_style=False))