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authorPeter Barabas <peter.barabas@ericsson.com>2016-07-07 17:40:28 +0200
committerPeter Barabas <peter.barabas@ericsson.com>2016-07-22 12:26:55 +0000
commit6d01c223e8bab2f5bab4941d12a1f09c5d5123b0 (patch)
treea8bf85494887b7b44ee566a3a4c21652e21bc586 /deploy/templater.py
parentb89e203b875737b0f251bf13ceb300b90e14b14f (diff)
Add templating support for generating config files
- Remove unneeded method - Write result to a file and not STDOUT - Add documentation - Remove trailing whitespace - Documentation corrections Change-Id: I7532222d3512380c4f1129bd05dc2ba37b409dc2 Signed-off-by: Peter Barabas <peter.barabas@ericsson.com>
Diffstat (limited to 'deploy/templater.py')
-rwxr-xr-xdeploy/templater.py169
1 files changed, 169 insertions, 0 deletions
diff --git a/deploy/templater.py b/deploy/templater.py
new file mode 100755
index 000000000..2ad6e05ba
--- /dev/null
+++ b/deploy/templater.py
@@ -0,0 +1,169 @@
+#!/usr/bin/env python
+###############################################################################
+# Copyright (c) 2016 Ericsson AB and others.
+# peter.barabas@ericsson.com
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Apache License, Version 2.0
+# which accompanies this distribution, and is available at
+# http://www.apache.org/licenses/LICENSE-2.0
+###############################################################################
+
+
+import io
+import re
+import yaml
+from common import(
+ err,
+ ArgParser,
+)
+
+
+TAG_START = '%{'
+TAG_END = '}'
+DELIMITER = '/'
+
+
+class Templater(object):
+ def __init__(self, base_file, template_file, output_file):
+ self.template_file = template_file
+ self.output_file = output_file
+ self.base = self.load_yaml(base_file)
+
+ def load_yaml(self, filename):
+ try:
+ with io.open(filename) as yaml_file:
+ return yaml.load(yaml_file)
+ except Exception as error:
+ err('Error opening YAML file: %s' % error)
+
+ def save_yaml(self, filename, content):
+ try:
+ with io.open(filename, 'w') as yaml_file:
+ yaml_file.write(content)
+ except Exception as error:
+ err('Error writing YAML file: %s' % error)
+
+ def get_indent(self, line):
+ return len(line) - len(line.lstrip(' '))
+
+ def format_fragment(self, fragment, indent):
+ result = ''
+ is_first_line = True
+
+ for line in fragment.splitlines():
+ # Skip indenting the first line as it is already indented
+ if is_first_line:
+ line += '\n'
+ is_first_line = False
+ else:
+ line = ' ' * indent + line + '\n'
+
+ result += line
+
+ return result.rstrip('\n')
+
+ def format_substitution(self, string):
+ if isinstance(string, basestring):
+ return string
+ else:
+ return yaml.dump(string, default_flow_style=False)
+
+ def parse_interface_tag(self, tag):
+ # Remove 'interface(' prefix, trailing ')' and split arguments
+ args = tag[len('interface('):].rstrip(')').split(',')
+
+ if len(args) == 1 and not args[0]:
+ err('No arguments for interface().')
+ elif len(args) == 2 and (not args[0] or not args[1]):
+ err('Empty argument for interface().')
+ elif len(args) > 2:
+ err('Too many arguments for interface().')
+ else:
+ return args
+
+ def get_interface_from_network(self, interfaces, network):
+ nics = self.base[interfaces]
+ for nic in nics:
+ if network in nics[nic]:
+ return nic
+
+ err('Network not found: %s' % network)
+
+ def get_role_interfaces(self, role):
+ nodes = self.base['nodes']
+ for node in nodes:
+ if role in node['role']:
+ return node['interfaces']
+
+ err('Role not found: %s' % role)
+
+ def lookup_interface(self, args):
+ nodes = self.base['nodes']
+
+ if len(args) == 1:
+ interfaces = nodes[0]['interfaces']
+ if len(args) == 2:
+ interfaces = self.get_role_interfaces(args[1])
+
+ return self.get_interface_from_network(interfaces, args[0])
+
+ def parse_tag(self, tag, indent):
+ fragment = ''
+
+ if 'interface(' in tag:
+ args = self.parse_interface_tag(tag)
+ fragment = self.lookup_interface(args)
+ else:
+ path = tag.split(DELIMITER)
+ fragment = self.base
+ for i in path:
+ if i in fragment:
+ fragment = fragment.get(i)
+ else:
+ err('Error: key "%s" does not exist in base YAML file' % i)
+
+ fragment = self.format_substitution(fragment)
+
+ return self.format_fragment(fragment, indent)
+
+ def run(self):
+ result = ''
+
+ regex = re.compile(re.escape(TAG_START) + r'([a-z].+)' + re.escape(TAG_END),
+ flags=re.IGNORECASE)
+ with io.open(self.template_file) as f:
+ for line in f:
+ indent = self.get_indent(line)
+ result += re.sub(regex,
+ lambda match: self.parse_tag(match.group(1), indent),
+ line)
+
+ self.save_yaml(self.output_file, result)
+
+
+def parse_arguments():
+ description = '''Process 'template_file' using 'base_file' as source for
+template variable substitution and write the results to 'output_file'.'''
+
+ parser = ArgParser(prog='python %s' % __file__,
+ description=description)
+ parser.add_argument('base_file',
+ help='Base YAML filename')
+ parser.add_argument('template_file',
+ help='Fragment filename')
+ parser.add_argument('output_file',
+ help='Output filename')
+
+ args = parser.parse_args()
+ return(args.base_file, args.template_file, args.output_file)
+
+
+def main():
+ base_file, template_file, output_file = parse_arguments()
+
+ templater = Templater(base_file, template_file, output_file)
+ templater.run()
+
+
+if __name__ == '__main__':
+ main()