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Extend wait_for module to support draining of active tcp connections

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This commit is contained in:
Greg Swift 2014-08-21 16:15:55 -05:00
parent 005ca0e5ec
commit 7bc23ea007
1 changed files with 217 additions and 4 deletions
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221
utilities/wait_for
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@ -23,6 +23,15 @@ import datetime
import time
import sys
import re
import binascii
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 = '''
---
@ -38,6 +47,9 @@ description:
- 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 X 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:
@ -62,10 +74,10 @@ options:
required: false
state:
description:
- either C(present), C(started), or C(stopped), C(absent)
- When checking a port C(started) will ensure the port is open, C(stopped) will check that it is closed
- 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" ]
choices: [ "present", "started", "stopped", "absent", "drained" ]
default: "started"
path:
version_added: "1.4"
@ -77,6 +89,11 @@ options:
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.x"
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: []
@ -88,6 +105,12 @@ 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
@ -105,6 +128,173 @@ EXAMPLES = '''
'''
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: '::',
}
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.name = module.params['name']
(self.family, self.ip) = _convert_host_to_ip(self.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):
if self.module.params['exclude_hosts'] is None:
return []
exclude_hosts = self.module.params['exclude_hosts'].split(',')
return [ _convert_host_to_hex(h)[1] for h in exclude_hosts ]
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 and self.ip in [self.match_all_ips[self.family], local_ip]:
(remote_ip, remote_port) = conn.remote_address
if remote_ip not in self.exclude_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',
}
local_address_field = 1
remote_address_field = 2
connection_state_field = 3
def __init__(self, module):
self.module = module
self.name = module.params['name']
(self.family, self.ip) = _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):
if self.module.params['exclude_hosts'] is None:
return []
exclude_hosts = self.module.params['exclude_hosts'].split(',')
return [ _convert_host_to_hex(h) for h in exclude_hosts ]
def get_active_connections_count(self):
active_connections = 0
f = open(self.source_file[self.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 and self.ip in [self.match_all_ips[self.family], local_ip]:
(remote_ip, remote_port) = tcp_connection[self.remote_address_field].split(':')
if remote_ip not in self.exclude_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:
Tuple containing address family and IP
"""
addrinfo = socket.getaddrinfo(host, 80, 0, 0, socket.SOL_TCP)[0]
return (addrinfo[0], addrinfo[4][0])
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:
Tuple containing address family and the little-endian converted host
"""
(family, ip) = _convert_host_to_ip(host)
hexed = binascii.hexlify(socket.inet_pton(family, ip)).upper()
if family == socket.AF_INET:
hexed = _little_endian_convert_32bit(hexed)
elif family == socket.AF_INET6:
# xrange loops through each 8 character (4B) set in the 128bit total
hexed = "".join([ _little_endian_convert_32bit(hexed[x:x+8]) for x in xrange(0, 32, 8) ])
return (family, hexed)
def _little_endian_convert_32bit(block):
"""
Convert to little-endian, effectively transposing
the order of the four byte word
12345678 -> 78563412
Args:
block: String containing a 4 byte hex representation
Returns:
String containing the little-endian converted block
"""
# xrange starts at 6, and increments by -2 until it reaches -2
# which lets us start at the end of the string block and work to the begining
return "".join([ block[x:x+2] for x in xrange(6, -2, -2) ])
def main():
module = AnsibleModule(
@ -116,7 +306,8 @@ def main():
port=dict(default=None),
path=dict(default=None),
search_regex=dict(default=None),
state=dict(default='started', choices=['started', 'stopped', 'present', 'absent']),
state=dict(default='started', choices=['started', 'stopped', 'present', 'absent', 'drained']),
exclude_hosts=dict(default=None, type='list')
),
)
@ -133,11 +324,19 @@ def main():
state = params['state']
path = params['path']
search_regex = params['search_regex']
if params['exclude_hosts']:
exclude_hosts = params['exclude_hosts'].split(',')
else:
exclude_hosts = []
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 exclude_hosts and state != 'drained':
module.fail_json(msg="exclude_hosts should only be with state=drained")
start = datetime.datetime.now()
@ -242,6 +441,20 @@ def main():
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)