diskimage-builder/elements/svc-map/extra-data.d/10-merge-svc-map-files
Ryan Brady e1853a7d5b Add svc-map element.
Adds a new svc-map element which can be used to install
services based on an in element 'svc-map' YAML config
file format.

This change is intended to decouple elements from DIB
and allow new elements to support multiple distributions
(with various service naming schemes) without having to
constantly maintain DIB's various bin/map-services files.

This patch ensures all of the YAML files are compiled into
a single file without namespaces.  The YAML compilation
process occurs during image creation time and errors if
conflicting mappings are found.

Change-Id: Id11433ea342aace71a358936a7ca3151ec11d506
2014-09-26 12:00:38 -04:00

70 lines
2.3 KiB
Python
Executable file

#!/usr/bin/env python
import os
import sys
import yaml
def os_family(distro):
"""Given a distribution, returns a operating system family."""
family = None
if distro in ['centos', 'fedora', 'rhel', 'rhel7']:
family = 'redhat'
elif distro in ['debian', 'ubuntu']:
family = 'debian'
elif distro == 'opensuse':
family = 'suse'
return family
def merge_data(source, destination, distro):
"""Merges two dictionaries and filters on distro, family, or default
(in order)."""
result = dict()
result.update(destination)
family = os_family(distro)
for servicename, mapping in source.iteritems():
if servicename in result:
raise Exception("%s already found in services list" % servicename)
if distro in mapping:
result[servicename] = mapping.get(distro)
elif family in mapping:
result[servicename] = mapping.get(family)
elif 'default' in mapping:
result[servicename] = mapping.get('default')
else:
result[servicename] = servicename
return result
def write_data_to_file(data, service_file_path):
"""Writes yaml data to a specified path."""
with open(service_file_path, 'w') as destination:
yaml.dump(data, destination, default_flow_style=False)
def main():
elements = os.environ.get("IMAGE_ELEMENT").split(' ')
element_paths = os.environ.get("ELEMENTS_PATH").split(':')
service_names = dict()
for element in elements:
for element_path in element_paths:
data_path = os.path.join(element_path, element, "svc-map")
if os.path.exists(data_path):
with open(data_path, 'r') as dataFile:
data = yaml.load(dataFile.read())
try:
service_names = merge_data(
data,
service_names,
os.environ.get("DISTRO_NAME"))
except Exception as err:
print("%s. Check %s for duplicate \
service name." % (err, element))
sys.exit(1)
write_data_to_file(service_names, os.path.join("/tmp", 'svc-map-services'))
if __name__ == "__main__":
main()