in library/haproxy_local.py [0:0]
def execute(self, cmd, timeout=200, capture_output=True):
"""
Executes a HAProxy command by sending a message to a HAProxy's local
UNIX socket and waiting up to 'timeout' milliseconds for the response.
"""
self.client = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
self.client.connect(self.socket)
self.client.sendall(to_bytes('%s\n' % cmd))
result = b''
buf = b''
buf = self.client.recv(RECV_SIZE)
while buf:
result += buf
buf = self.client.recv(RECV_SIZE)
result = to_text(result, errors='surrogate_or_strict')
if capture_output:
self.capture_command_output(cmd, result.strip())
self.client.close()
return result
def capture_command_output(self, cmd, output):
"""
Capture the output for a command
"""
if 'command' not in self.command_results:
self.command_results['command'] = []
self.command_results['command'].append(cmd)
if 'output' not in self.command_results:
self.command_results['output'] = []
self.command_results['output'].append(output)
def discover_all_backends(self):
"""
Discover all entries with svname = 'BACKEND' and return a list of their corresponding
pxnames
"""
data = self.execute('show stat', 200, False).lstrip('# ')
r = csv.DictReader(data.splitlines())
return tuple(map(lambda d: d['pxname'], filter(lambda d: d['svname'] == 'BACKEND', r)))
def discover_version(self):
"""
Attempt to extract the haproxy version.
Return a tuple containing major and minor version.
"""
data = self.execute('show info', 200, False)
lines = data.splitlines()
line = [x for x in lines if 'Version:' in x]
try:
version_values = line[0].partition(':')[2].strip().split('.', 3)
version = (int(version_values[0]), int(version_values[1]))
except (ValueError, TypeError, IndexError):
version = None
return version
def execute_for_backends(self, cmd, pxname, svname, wait_for_status=None):
"""
Run some command on the specified backends. If no backends are provided they will
be discovered automatically (all backends)
"""
# Discover backends if none are given
if pxname is None:
backends = self.discover_all_backends()
else:
backends = [pxname]
# Run the command for each requested backend
for backend in backends:
# Fail when backends were not found
state = self.get_state_for(backend, svname)
if (self.fail_on_not_found) and state is None:
self.module.fail_json(
msg="The specified backend '%s/%s' was not found!" % (backend, svname))
if state is not None:
self.execute(Template(cmd).substitute(pxname=backend, svname=svname))
if self.wait:
self.wait_until_status(backend, svname, wait_for_status)
def get_state_for(self, pxname, svname):
"""
Find the state of specific services. When pxname is not set, get all backends for a specific host.
Returns a list of dictionaries containing the status and weight for those services.
"""
data = self.execute('show stat', 200, False).lstrip('# ')
r = csv.DictReader(data.splitlines())
state = tuple(
map(
lambda d: {'status': d['status'], 'weight': d['weight'], 'scur': d['scur']},
filter(lambda d: (pxname is None or d['pxname']
== pxname) and d['svname'] == svname, r)
)
)
return state or None
def wait_until_status(self, pxname, svname, status):
"""
Wait for a service to reach the specified status. Try RETRIES times
with INTERVAL seconds of sleep in between. If the service has not reached
the expected status in that time, the module will fail. If the service was
not found, the module will fail.
"""
for i in range(1, self.wait_retries):
state = self.get_state_for(pxname, svname)
# We can assume there will only be 1 element in state because both svname and pxname are always set when we get here
if state[0]['status'] == status:
if not self._drain or (state[0]['scur'] == '0' and state == 'MAINT'):
return True
else:
time.sleep(self.wait_interval)
self.module.fail_json(msg="server %s/%s not status '%s' after %d retries. Aborting." %
(pxname, svname, status, self.wait_retries))
def enabled(self, host, backend, weight):
"""
Enabled action, marks server to UP and checks are re-enabled,
also supports to get current weight for server (default) and
set the weight for haproxy backend server when provides.
"""
cmd = "get weight $pxname/$svname; enable server $pxname/$svname"
if weight:
cmd += "; set weight $pxname/$svname %s" % weight
self.execute_for_backends(cmd, backend, host, 'UP')
def disabled(self, host, backend, shutdown_sessions):
"""
Disabled action, marks server to DOWN for maintenance. In this mode, no more checks will be
performed on the server until it leaves maintenance,
also it shutdown sessions while disabling backend host server.
"""
cmd = "get weight $pxname/$svname; disable server $pxname/$svname"
if shutdown_sessions:
cmd += "; shutdown sessions server $pxname/$svname"
self.execute_for_backends(cmd, backend, host, 'MAINT')
def drain(self, host, backend, status='DRAIN'):
"""
Drain action, sets the server to DRAIN mode.
In this mode mode, the server will not accept any new connections
other than those that are accepted via persistence.
"""
haproxy_version = self.discover_version()
# check if haproxy version suppots DRAIN state (starting with 1.5)
if haproxy_version and (1, 5) <= haproxy_version:
cmd = "set server $pxname/$svname state drain"
self.execute_for_backends(cmd, backend, host, status)
def act(self):
"""
Figure out what you want to do from ansible, and then do it.