ansible/library/commands/command

246 lines
8.4 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>, and others
#
# 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/>.
import sys
import datetime
import traceback
import re
import shlex
import os
DOCUMENTATION = '''
---
module: command
version_added: historical
short_description: Executes a command on a remote node
description:
- The M(command) module takes the command name followed by a list of space-delimited arguments.
- The given command will be executed on all selected nodes. It will not be
processed through the shell, so variables like C($HOME) and operations
like C("<"), C(">"), C("|"), and C("&") will not work (use the M(shell)
module if you need these features).
options:
free_form:
description:
- the command module takes a free form command to run. There is no parameter actually named 'free form'.
See the examples!
required: true
default: null
aliases: []
creates:
description:
- a filename, when it already exists, this step will B(not) be run.
required: no
default: null
removes:
description:
- a filename, when it does not exist, this step will B(not) be run.
version_added: "0.8"
required: no
default: null
chdir:
description:
- cd into this directory before running the command
version_added: "0.6"
required: false
default: null
executable:
description:
- change the shell used to execute the command. Should be an absolute path to the executable.
required: false
default: null
version_added: "0.9"
notes:
- If you want to run a command through the shell (say you are using C(<),
C(>), C(|), etc), you actually want the M(shell) module instead. The
M(command) module is much more secure as it's not affected by the user's
environment.
- " C(creates), C(removes), and C(chdir) can be specified after the command. For instance, if you only want to run a command if a certain file does not exist, use this."
author: Michael DeHaan
'''
EXAMPLES = '''
# Example from Ansible Playbooks.
- command: /sbin/shutdown -t now
# Run the command if the specified file does not exist.
- command: /usr/bin/make_database.sh arg1 arg2 creates=/path/to/database
# You can also use the 'args' form to provide the options. This command
# will change the working directory to somedir/ and will only run when
# /path/to/database doesn't exist.
- command: /usr/bin/make_database.sh arg1 arg2
args:
chdir: somedir/
creates: /path/to/database
'''
# This is a pretty complex regex, which functions as follows:
#
# 1. (^|\s)
# ^ look for a space or the beginning of the line
# 2. (creates|removes|chdir|executable|NO_LOG)=
# ^ look for a valid param, followed by an '='
# 3. (?P<quote>[\'"])?
# ^ look for an optional quote character, which can either be
# a single or double quote character, and store it for later
# 4. (.*?)
# ^ match everything in a non-greedy manner until...
# 5. (?(quote)(?<!\\)(?P=quote))((?<!\\)(?=\s)|$)
# ^ a non-escaped space or a non-escaped quote of the same kind
# that was matched in the first 'quote' is found, or the end of
# the line is reached
PARAM_REGEX = re.compile(r'(^|\s)(creates|removes|chdir|executable|NO_LOG)=(?P<quote>[\'"])?(.*?)(?(quote)(?<!\\)(?P=quote))((?<!\\)(?=\s)|$)')
def main():
# the command module is the one ansible module that does not take key=value args
# hence don't copy this one if you are looking to build others!
module = CommandModule(argument_spec=dict())
shell = module.params['shell']
chdir = module.params['chdir']
executable = module.params['executable']
args = module.params['args']
creates = module.params['creates']
removes = module.params['removes']
if args.strip() == '':
module.fail_json(rc=256, msg="no command given")
if chdir:
os.chdir(chdir)
if creates:
# do not run the command if the line contains creates=filename
# and the filename already exists. This allows idempotence
# of command executions.
v = os.path.expanduser(creates)
if os.path.exists(v):
module.exit_json(
cmd=args,
stdout="skipped, since %s exists" % v,
skipped=True,
changed=False,
stderr=False,
rc=0
)
if removes:
# do not run the command if the line contains removes=filename
# and the filename does not exist. This allows idempotence
# of command executions.
v = os.path.expanduser(removes)
if not os.path.exists(v):
module.exit_json(
cmd=args,
stdout="skipped, since %s does not exist" % v,
skipped=True,
changed=False,
stderr=False,
rc=0
)
if not shell:
args = shlex.split(args)
startd = datetime.datetime.now()
rc, out, err = module.run_command(args, executable=executable, use_unsafe_shell=shell)
endd = datetime.datetime.now()
delta = endd - startd
if out is None:
out = ''
if err is None:
err = ''
module.exit_json(
cmd = args,
stdout = out.rstrip("\r\n"),
stderr = err.rstrip("\r\n"),
rc = rc,
start = str(startd),
end = str(endd),
delta = str(delta),
changed = True
)
# import module snippets
from ansible.module_utils.basic import *
# only the command module should ever need to do this
# everything else should be simple key=value
class CommandModule(AnsibleModule):
def _handle_aliases(self):
return {}
def _check_invalid_arguments(self):
pass
def _load_params(self):
''' read the input and return a dictionary and the arguments string '''
args = MODULE_ARGS
params = {}
params['chdir'] = None
params['creates'] = None
params['removes'] = None
params['shell'] = False
params['executable'] = None
if "#USE_SHELL" in args:
args = args.replace("#USE_SHELL", "")
params['shell'] = True
# use shlex to split up the args, while being careful to preserve
# single quotes so they're not removed accidentally
lexer = shlex.shlex(args)
lexer.whitespace = '\t '
lexer.whitespace_split = True
items = list(lexer)
for x in items:
quoted = x.startswith('"') and x.endswith('"') or x.startswith("'") and x.endswith("'")
if '=' in x and not quoted:
# check to see if this is a special parameter for the command
k, v = x.split('=', 1)
# because we're not breaking out quotes in the shlex split
# above, the value of the k=v pair may still be quoted. If
# so, remove them.
if len(v) > 1 and (v.startswith('"') and v.endswith('"') or v.startswith("'") and v.endswith("'")):
v = v[1:-1]
if k in ('creates', 'removes', 'chdir', 'executable', 'NO_LOG'):
if k == "chdir":
v = os.path.abspath(os.path.expanduser(v))
if not (os.path.exists(v) and os.path.isdir(v)):
self.fail_json(rc=258, msg="cannot change to directory '%s': path does not exist" % v)
elif k == "executable":
v = os.path.abspath(os.path.expanduser(v))
if not (os.path.exists(v)):
self.fail_json(rc=258, msg="cannot use executable '%s': file does not exist" % v)
params[k] = v
# Remove any of the above k=v params from the args string
args = PARAM_REGEX.sub('', args)
params['args'] = args.strip()
return (params, params['args'])
main()