ansible/library/system/alternatives
2014-03-16 16:54:57 -04:00

137 lines
4.2 KiB
Python
Executable file

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""
Ansible module to manage symbolic link alternatives.
(c) 2014, Gabe Mulley <gabe.mulley@gmail.com>
This file is part of Ansible
Ansible is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Ansible is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Ansible. If not, see <http://www.gnu.org/licenses/>.
"""
DOCUMENTATION = '''
---
module: alternatives
short_description: Manages alternative programs for common commands
description:
- Manages symbolic links using the 'update-alternatives' tool provided on debian-like systems.
- Useful when multiple programs are installed but provide similar functionality (e.g. different editors).
version_added: "1.6"
options:
name:
description:
- The generic name of the link.
required: true
path:
description:
- The path to the real executable that the link should point to.
required: true
link:
description:
- The path to the symbolic link that should point to the real executable.
required: false
requirements: [ update-alternatives ]
'''
EXAMPLES = '''
- name: correct java version selected
alternatives: name=java path=/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
- name: alternatives link created
alternatives: name=hadoop-conf link=/etc/hadoop/conf path=/etc/hadoop/conf.ansible
'''
UPDATE_ALTERNATIVES = '/usr/sbin/update-alternatives'
DEFAULT_LINK_PRIORITY = 50
def main():
module = AnsibleModule(
argument_spec = dict(
name = dict(required=True),
path = dict(required=True),
link = dict(required=False),
)
)
params = module.params
name = params['name']
path = params['path']
link = params['link']
current_path = None
all_alternatives = []
(rc, query_output, query_error) = module.run_command(
[UPDATE_ALTERNATIVES, '--query', name]
)
# Gather the current setting and all alternatives from the query output.
# Query output should look something like this:
# Name: java
# Link: /usr/bin/java
# Slaves:
# java.1.gz /usr/share/man/man1/java.1.gz
# Status: manual
# Best: /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
# Value: /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java
# Alternative: /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java
# Priority: 1061
# Slaves:
# java.1.gz /usr/lib/jvm/java-6-openjdk-amd64/jre/man/man1/java.1.gz
# Alternative: /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
# Priority: 1071
# Slaves:
# java.1.gz /usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/java.1.gz
if rc == 0:
for line in query_output.splitlines():
split_line = line.split(':')
if len(split_line) == 2:
key = split_line[0]
value = split_line[1].strip()
if key == 'Value':
current_path = value
elif key == 'Alternative':
all_alternatives.append(value)
if current_path != path:
try:
# install the requested path if necessary
if path not in all_alternatives:
module.run_command(
[UPDATE_ALTERNATIVES, '--install', link, name, path, str(DEFAULT_LINK_PRIORITY)],
check_rc=True
)
# select the requested path
module.run_command(
[UPDATE_ALTERNATIVES, '--set', name, path],
check_rc=True
)
module.exit_json(changed=True)
except subprocess.CalledProcessError as cpe:
module.fail_json(msg=str(dir(cpe)))
else:
module.exit_json(changed=False)
# import module snippets
from ansible.module_utils.basic import *
main()