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ansible/utilities/logic/wait_for.py
Stanislav Antic f0f5272f90 Fix wait_for on python < 2.6 (#3790) (#3973)
2016-06-17 10:04:26 -04:00

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#!/usr/bin/python
# -*- coding: utf-8 -*-
# (c) 2012, Jeroen Hoekx <jeroen@hoekx.be>
#
# 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 binascii
import datetime
import math
import re
import select
import socket
import sys
import time
HAS_PSUTIL = False
try:
import psutil
HAS_PSUTIL = True
# just because we can import it on Linux doesn't mean we will use it
except ImportError:
pass
DOCUMENTATION = '''
---
module: wait_for
short_description: Waits for a condition before continuing.
description:
- You can wait for a set amount of time C(timeout), this is the default if nothing is specified.
- Waiting for a port to become available is useful for when services
are not immediately available after their init scripts return
which is true of certain Java application servers. It is also
useful when starting guests with the M(virt) module and
needing to pause until they are ready.
- This module can also be used to wait for a regex match a string to be present in a file.
- In 1.6 and later, this module can also be used to wait for a file to be available or
absent on the filesystem.
- In 1.8 and later, this module can also be used to wait for active
connections to be closed before continuing, useful if a node
is being rotated out of a load balancer pool.
version_added: "0.7"
options:
host:
description:
- A resolvable hostname or IP address to wait for
required: false
default: "127.0.0.1"
timeout:
description:
- maximum number of seconds to wait for
required: false
default: 300
connect_timeout:
description:
- maximum number of seconds to wait for a connection to happen before closing and retrying
required: false
default: 5
delay:
description:
- number of seconds to wait before starting to poll
required: false
default: 0
port:
description:
- port number to poll
required: false
state:
description:
- either C(present), C(started), or C(stopped), C(absent), or C(drained)
- When checking a port C(started) will ensure the port is open, C(stopped) will check that it is closed, C(drained) will check for active connections
- When checking for a file or a search string C(present) or C(started) will ensure that the file or string is present before continuing, C(absent) will check that file is absent or removed
choices: [ "present", "started", "stopped", "absent", "drained" ]
default: "started"
path:
version_added: "1.4"
required: false
description:
- path to a file on the filesytem that must exist before continuing
search_regex:
version_added: "1.4"
required: false
description:
- Can be used to match a string in either a file or a socket connection. Defaults to a multiline regex.
exclude_hosts:
version_added: "1.8"
required: false
description:
- list of hosts or IPs to ignore when looking for active TCP connections for C(drained) state
notes:
- The ability to use search_regex with a port connection was added in 1.7.
requirements: []
author:
- "Jeroen Hoekx (@jhoekx)"
- "John Jarvis (@jarv)"
- "Andrii Radyk (@AnderEnder)"
'''
EXAMPLES = '''
# wait 300 seconds for port 8000 to become open on the host, don't start checking for 10 seconds
- wait_for: port=8000 delay=10
# wait 300 seconds for port 8000 of any IP to close active connections, don't start checking for 10 seconds
- wait_for: host=0.0.0.0 port=8000 delay=10 state=drained
# wait 300 seconds for port 8000 of any IP to close active connections, ignoring connections for specified hosts
- wait_for: host=0.0.0.0 port=8000 state=drained exclude_hosts=10.2.1.2,10.2.1.3
# wait until the file /tmp/foo is present before continuing
- wait_for: path=/tmp/foo
# wait until the string "completed" is in the file /tmp/foo before continuing
- wait_for: path=/tmp/foo search_regex=completed
# wait until the lock file is removed
- wait_for: path=/var/lock/file.lock state=absent
# wait until the process is finished and pid was destroyed
- wait_for: path=/proc/3466/status state=absent
# wait 300 seconds for port 22 to become open and contain "OpenSSH", don't assume the inventory_hostname is resolvable
# and don't start checking for 10 seconds
- local_action: wait_for port=22 host="{{ ansible_ssh_host | default(inventory_hostname) }}" search_regex=OpenSSH delay=10
'''
class TCPConnectionInfo(object):
"""
This is a generic TCP Connection Info strategy class that relies
on the psutil module, which is not ideal for targets, but necessary
for cross platform support.
A subclass may wish to override some or all of these methods.
- _get_exclude_ips()
- get_active_connections()
All subclasses MUST define platform and distribution (which may be None).
"""
platform = 'Generic'
distribution = None
match_all_ips = {
socket.AF_INET: '0.0.0.0',
socket.AF_INET6: '::',
}
ipv4_mapped_ipv6_address = {
'prefix': '::ffff',
'match_all': '::ffff:0.0.0.0'
}
connection_states = {
'01': 'ESTABLISHED',
'02': 'SYN_SENT',
'03': 'SYN_RECV',
'04': 'FIN_WAIT1',
'05': 'FIN_WAIT2',
'06': 'TIME_WAIT',
}
def __new__(cls, *args, **kwargs):
return load_platform_subclass(TCPConnectionInfo, args, kwargs)
def __init__(self, module):
self.module = module
self.ips = _convert_host_to_ip(module.params['host'])
self.port = int(self.module.params['port'])
self.exclude_ips = self._get_exclude_ips()
if not HAS_PSUTIL:
module.fail_json(msg="psutil module required for wait_for")
def _get_exclude_ips(self):
exclude_hosts = self.module.params['exclude_hosts']
exclude_ips = []
if exclude_hosts is not None:
for host in exclude_hosts:
exclude_ips.extend(_convert_host_to_ip(host))
return exclude_ips
def get_active_connections_count(self):
active_connections = 0
for p in psutil.process_iter():
connections = p.get_connections(kind='inet')
for conn in connections:
if conn.status not in self.connection_states.values():
continue
(local_ip, local_port) = conn.local_address
if self.port != local_port:
continue
(remote_ip, remote_port) = conn.remote_address
if (conn.family, remote_ip) in self.exclude_ips:
continue
if any((
(conn.family, local_ip) in self.ips,
(conn.family, self.match_all_ips[conn.family]) in self.ips,
local_ip.startswith(self.ipv4_mapped_ipv6_address['prefix']) and
(conn.family, self.ipv4_mapped_ipv6_address['match_all']) in self.ips,
)):
active_connections += 1
return active_connections
# ===========================================
# Subclass: Linux
class LinuxTCPConnectionInfo(TCPConnectionInfo):
"""
This is a TCP Connection Info evaluation strategy class
that utilizes information from Linux's procfs. While less universal,
does allow Linux targets to not require an additional library.
"""
platform = 'Linux'
distribution = None
source_file = {
socket.AF_INET: '/proc/net/tcp',
socket.AF_INET6: '/proc/net/tcp6'
}
match_all_ips = {
socket.AF_INET: '00000000',
socket.AF_INET6: '00000000000000000000000000000000',
}
ipv4_mapped_ipv6_address = {
'prefix': '0000000000000000FFFF0000',
'match_all': '0000000000000000FFFF000000000000'
}
local_address_field = 1
remote_address_field = 2
connection_state_field = 3
def __init__(self, module):
self.module = module
self.ips = _convert_host_to_hex(module.params['host'])
self.port = "%0.4X" % int(module.params['port'])
self.exclude_ips = self._get_exclude_ips()
def _get_exclude_ips(self):
exclude_hosts = self.module.params['exclude_hosts']
exclude_ips = []
if exclude_hosts is not None:
for host in exclude_hosts:
exclude_ips.extend(_convert_host_to_hex(host))
return exclude_ips
def get_active_connections_count(self):
active_connections = 0
for family in self.source_file.keys():
f = open(self.source_file[family])
for tcp_connection in f.readlines():
tcp_connection = tcp_connection.strip().split()
if tcp_connection[self.local_address_field] == 'local_address':
continue
if tcp_connection[self.connection_state_field] not in self.connection_states:
continue
(local_ip, local_port) = tcp_connection[self.local_address_field].split(':')
if self.port != local_port:
continue
(remote_ip, remote_port) = tcp_connection[self.remote_address_field].split(':')
if (family, remote_ip) in self.exclude_ips:
continue
if any((
(family, local_ip) in self.ips,
(family, self.match_all_ips[family]) in self.ips,
local_ip.startswith(self.ipv4_mapped_ipv6_address['prefix']) and
(family, self.ipv4_mapped_ipv6_address['match_all']) in self.ips,
)):
active_connections += 1
f.close()
return active_connections
def _convert_host_to_ip(host):
"""
Perform forward DNS resolution on host, IP will give the same IP
Args:
host: String with either hostname, IPv4, or IPv6 address
Returns:
List of tuples containing address family and IP
"""
addrinfo = socket.getaddrinfo(host, 80, 0, 0, socket.SOL_TCP)
ips = []
for family, socktype, proto, canonname, sockaddr in addrinfo:
ip = sockaddr[0]
ips.append((family, ip))
if family == socket.AF_INET:
ips.append((socket.AF_INET6, "::ffff:" + ip))
return ips
def _convert_host_to_hex(host):
"""
Convert the provided host to the format in /proc/net/tcp*
/proc/net/tcp uses little-endian four byte hex for ipv4
/proc/net/tcp6 uses little-endian per 4B word for ipv6
Args:
host: String with either hostname, IPv4, or IPv6 address
Returns:
List of tuples containing address family and the
little-endian converted host
"""
ips = []
if host is not None:
for family, ip in _convert_host_to_ip(host):
hexip_nf = binascii.b2a_hex(socket.inet_pton(family, ip))
hexip_hf = ""
for i in range(0, len(hexip_nf), 8):
ipgroup_nf = hexip_nf[i:i+8]
ipgroup_hf = socket.ntohl(int(ipgroup_nf, base=16))
hexip_hf = "%s%08X" % (hexip_hf, ipgroup_hf)
ips.append((family, hexip_hf))
return ips
def _create_connection(host, port, connect_timeout):
"""
Connect to a 2-tuple (host, port) and return
the socket object.
Args:
2-tuple (host, port) and connection timeout
Returns:
Socket object
"""
if sys.version_info < (2, 6):
(family, _) = (_convert_host_to_ip(host))[0]
connect_socket = socket.socket(family, socket.SOCK_STREAM)
connect_socket.settimeout(connect_timeout)
connect_socket.connect( (host, port) )
else:
connect_socket = socket.create_connection( (host, port), connect_timeout)
return connect_socket
def _timedelta_total_seconds(timedelta):
return (
timedelta.microseconds + 0.0 +
(timedelta.seconds + timedelta.days * 24 * 3600) * 10 ** 6) / 10 ** 6
def main():
module = AnsibleModule(
argument_spec = dict(
host=dict(default='127.0.0.1'),
timeout=dict(default=300, type='int'),
connect_timeout=dict(default=5, type='int'),
delay=dict(default=0, type='int'),
port=dict(default=None, type='int'),
path=dict(default=None, type='path'),
search_regex=dict(default=None),
state=dict(default='started', choices=['started', 'stopped', 'present', 'absent', 'drained']),
exclude_hosts=dict(default=None, type='list')
),
)
params = module.params
host = params['host']
timeout = params['timeout']
connect_timeout = params['connect_timeout']
delay = params['delay']
port = params['port']
state = params['state']
path = params['path']
search_regex = params['search_regex']
if search_regex is not None:
compiled_search_re = re.compile(search_regex, re.MULTILINE)
else:
compiled_search_re = None
if port and path:
module.fail_json(msg="port and path parameter can not both be passed to wait_for")
if path and state == 'stopped':
module.fail_json(msg="state=stopped should only be used for checking a port in the wait_for module")
if path and state == 'drained':
module.fail_json(msg="state=drained should only be used for checking a port in the wait_for module")
if params['exclude_hosts'] is not None and state != 'drained':
module.fail_json(msg="exclude_hosts should only be with state=drained")
start = datetime.datetime.now()
if delay:
time.sleep(delay)
if not port and not path and state != 'drained':
time.sleep(timeout)
elif state in [ 'stopped', 'absent' ]:
### first wait for the stop condition
end = start + datetime.timedelta(seconds=timeout)
while datetime.datetime.now() < end:
if path:
try:
f = open(path)
f.close()
time.sleep(1)
pass
except IOError:
break
elif port:
try:
s = _create_connection(host, port, connect_timeout)
s.shutdown(socket.SHUT_RDWR)
s.close()
time.sleep(1)
except:
break
else:
time.sleep(1)
else:
elapsed = datetime.datetime.now() - start
if port:
module.fail_json(msg="Timeout when waiting for %s:%s to stop." % (host, port), elapsed=elapsed.seconds)
elif path:
module.fail_json(msg="Timeout when waiting for %s to be absent." % (path), elapsed=elapsed.seconds)
elif state in ['started', 'present']:
### wait for start condition
end = start + datetime.timedelta(seconds=timeout)
while datetime.datetime.now() < end:
if path:
try:
os.stat(path)
except OSError:
e = get_exception()
# If anything except file not present, throw an error
if e.errno != 2:
elapsed = datetime.datetime.now() - start
module.fail_json(msg="Failed to stat %s, %s" % (path, e.strerror), elapsed=elapsed.seconds)
# file doesn't exist yet, so continue
else:
# File exists. Are there additional things to check?
if not compiled_search_re:
# nope, succeed!
break
try:
f = open(path)
try:
if re.search(compiled_search_re, f.read()):
# String found, success!
break
finally:
f.close()
except IOError:
pass
elif port:
alt_connect_timeout = math.ceil(_timedelta_total_seconds(end - datetime.datetime.now()))
try:
s = _create_connection(host, port, min(connect_timeout, alt_connect_timeout))
except:
# Failed to connect by connect_timeout. wait and try again
pass
else:
# Connected -- are there additional conditions?
if compiled_search_re:
data = ''
matched = False
while datetime.datetime.now() < end:
max_timeout = math.ceil(_timedelta_total_seconds(end - datetime.datetime.now()))
(readable, w, e) = select.select([s], [], [], max_timeout)
if not readable:
# No new data. Probably means our timeout
# expired
continue
response = s.recv(1024)
if not response:
# Server shutdown
break
data += response
if re.search(compiled_search_re, data):
matched = True
break
# Shutdown the client socket
s.shutdown(socket.SHUT_RDWR)
s.close()
if matched:
# Found our string, success!
break
else:
# Connection established, success!
s.shutdown(socket.SHUT_RDWR)
s.close()
break
# Conditions not yet met, wait and try again
time.sleep(1)
else: # while-else
# Timeout expired
elapsed = datetime.datetime.now() - start
if port:
if search_regex:
module.fail_json(msg="Timeout when waiting for search string %s in %s:%s" % (search_regex, host, port), elapsed=elapsed.seconds)
else:
module.fail_json(msg="Timeout when waiting for %s:%s" % (host, port), elapsed=elapsed.seconds)
elif path:
if search_regex:
module.fail_json(msg="Timeout when waiting for search string %s in %s" % (search_regex, path), elapsed=elapsed.seconds)
else:
module.fail_json(msg="Timeout when waiting for file %s" % (path), elapsed=elapsed.seconds)
elif state == 'drained':
### wait until all active connections are gone
end = start + datetime.timedelta(seconds=timeout)
tcpconns = TCPConnectionInfo(module)
while datetime.datetime.now() < end:
try:
if tcpconns.get_active_connections_count() == 0:
break
except IOError:
pass
time.sleep(1)
else:
elapsed = datetime.datetime.now() - start
module.fail_json(msg="Timeout when waiting for %s:%s to drain" % (host, port), elapsed=elapsed.seconds)
elapsed = datetime.datetime.now() - start
module.exit_json(state=state, port=port, search_regex=search_regex, path=path, elapsed=elapsed.seconds)
# import module snippets
from ansible.module_utils.basic import *
if __name__ == '__main__':
main()
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