scripts/gen_app_yaml.py

   1 #! /usr/bin/python2.5
   2
   3 # Copyright 2009 the Melange authors.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #   http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 """A script to generate the app.yaml from the template with an application
  18 name filled in.
  19
  20 Usage:
  21   gen_app_yaml.py [-f] APPLICATION_NAME
  22
  23 Arguments:
  24   APPLICATION_NAME: the name to use for the application (no underscores)
  25
  26 Flags:
  27   -f:  overwrite an existing app.yaml (default=false)
  28 """
  29
  30 from __future__ import with_statement
  31
  32 __authors__ = [
  33     # alphabetical order by last name, please
  34     '"Dan Bentley" <dbentley@google.com>',
  35     ]
  36
  37
  38 import os
  39 import sys
  40
  41
  42 def generateAppYaml(application_name, force=False):
  43   """Generate the app.yaml file.
  44
  45   Args:
  46     application_name: str, the name to write into the application filed
  47     force: bool, whether to overwrite an existing app.yaml
  48   """
  49
  50   scripts_directory = os.path.dirname(__file__)
  51   app_dir = os.path.abspath(os.path.join(scripts_directory, '../app'))
  52   template_path = os.path.join(app_dir, 'app.yaml.template')
  53   app_yaml_path = os.path.join(app_dir, 'app.yaml')
  54
  55   if not os.path.exists(template_path):
  56     sys.exit("Template file %s non-existent. Corrupt client?" % template_path)
  57
  58   if os.path.exists(app_yaml_path):
  59     if not force:
  60       sys.exit("%s exists; exiting. To overwrite, pass -f on the command-line"
  61                % app_yaml_path)
  62
  63   with open(template_path) as infile:
  64     template_contents = infile.read()
  65
  66   app_yaml_contents = template_contents.replace(
  67       '# application: FIXME',
  68       'application: '+ application_name)
  69
  70   with open(app_yaml_path, 'w') as outfile:
  71     outfile.write(app_yaml_contents)
  72
  73   print "Wrote application name %s to %s." % (application_name, app_yaml_path)
  74
  75
  76 def usage(msg):
  77   """Print an error message and the usage of the program; then quit.
  78   """
  79
  80   sys.exit('Error: %s\n\n%s' % (msg, __doc__))
  81
  82
  83 def main(args):
  84   """Main program.
  85   """
  86
  87   if not args:
  88     usage("No arguments supplied.")
  89
  90   if args[0] == '-f':
  91     force = True
  92     args = args[1:]
  93   else:
  94     force = False
  95
  96   if len(args) != 1:
  97     usage("No application name supplied.")
  98
  99   application_name = args[0]
 100   generateAppYaml(application_name, force=force)
 101
 102
 103 if __name__ == '__main__':
 104   main(sys.argv[1:]) # strip off the binary name