Merge pull request #1593 from deis/contrib/gce/flake8

chore(contrib/gce): make GCE script pass flake8

Author: Xe

contrib/gce/create-gce-user-data

@@ -5,9 +5,8 @@ Create CoreOS user-data by merging contric/coreos/user-data and gce-user-data
 Usage: create-gce-user-data.py <discovery_url>
 
 Arguments:
-  <discovery_url>
-    This is the CoreOS etcd discovery URL. You should generate a new URL at
-    https://discovery.etcd.io/new and pass it as the argument.
+    <discovery_url> This is the CoreOS etcd discovery URL. You should generate
+    a new URL at https://discovery.etcd.io/new and pass it as the argument.
 """
 
 import sys
@@ -16,48 +15,67 @@ import re
 import yaml
 import collections
 
-# TODO: Learn how to use docopt and import it for argument handling and validtion
 
 def combine_dicts(orig_dict, new_dict):
     for key, val in new_dict.iteritems():
         if isinstance(val, collections.Mapping):
-            tmp = combine_dicts(orig_dict.get(key, { }), val)
+            tmp = combine_dicts(orig_dict.get(key, {}), val)
             orig_dict[key] = tmp
         elif isinstance(val, list):
             orig_dict[key] = (orig_dict[key] + val)
         else:
             orig_dict[key] = new_dict[key]
     return orig_dict
 
-try:
-  url = sys.argv[1]
-except (NameError, IndexError):
-  exit('It doesn\'t appear that you specified a discovery URL as the first parameter.')
 
+def get_file(name, mode="r", abspath=False):
+    current_dir = os.path.dirname(__file__)
 
-url_pattern = 'https\:[\/]{2}discovery\.etcd\.io\/[0-9a-f]{32}'
+    if abspath:
+        return file(os.path.abspath(os.path.join(current_dir, name)), mode)
+    else:
+        return file(os.path.join(current_dir, name), mode)
 
-m = re.match(url_pattern, url)
 
-if url and m:
-  current_dir = os.path.dirname(__file__)
-  gce_user_data = file(os.path.abspath(os.path.join(current_dir, 'gce-user-data')), 'w')
-  gce_template = file(os.path.join(current_dir, "gce-user-data-template"), 'r')
-  coreos_template = file(os.path.join(current_dir, "../coreos/user-data"), 'r')
+def main():
+    try:
+        url = sys.argv[1]
+    except (NameError, IndexError):
+        print __doc__
+        return 1
 
-  configuration_coreos_template = yaml.safe_load(coreos_template)
-  configuration_gce_template = yaml.safe_load(gce_template)
+    url_pattern = 'http[|s]\:[\/]{2}discovery\.etcd\.io\/[0-9a-f]{32}'
 
-  configuration = combine_dicts(configuration_coreos_template, configuration_gce_template)
-  
-  configuration['coreos']['etcd']['discovery_url'] = url
+    m = re.match(url_pattern, url)
 
-  with gce_user_data as outfile:
-    try:
-      outfile.write("#cloud-config\n\n" + yaml.safe_dump(configuration, default_flow_style=False,  default_style='|'))
-    except (IOError, ValueError):
-      exit('There was an issue writing to file ' + gce_user_data.name)
-    else:
-      exit('Wrote file ' + gce_user_data.name + ' with discovery URL ' + url)
-else:
-  print 'Discovery URL doesn\'t appear to be valid.'
+    if not m:
+        print "Discovery URL invalid."
+        return 1
+
+    gce_user_data = get_file("gce_user_data", "w", True)
+    gce_template = get_file("gce-user-data-template")
+    coreos_template = get_file("../coreos/user-data")
+
+    configuration_coreos_template = yaml.safe_load(coreos_template)
+    configuration_gce_template = yaml.safe_load(gce_template)
+
+    configuration = combine_dicts(configuration_coreos_template,
+                                  configuration_gce_template)
+
+    configuration["coreos"]["etcd"]["discovery_url"] = url
+
+    with gce_user_data as outfile:
+        try:
+            outfile.write("#cloud-config\n\n" +
+                          yaml.safe_dump(configuration,
+                                         default_flow_style=False,
+                                         default_style='|'))
+        except (IOError, ValueError):
+            print "There was an issue writing to file " + gce_user_data.name
+            return 1
+        else:
+            print "Wrote file \"%s\" with url \"%s\"" %\
+                (gce_user_data.name, url)
+
+if __name__ == "__main__":
+    sys.exit(main())