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|
# -*- coding: utf-8 -*-
#
# pylint: disable=superfluous-parens
#
"""
haproxyadmin.internal.backend
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This module provides a class, which is used within haproxyadmin for creating a
object to work with a backend. This object is associated only with a single
HAProxy process.
"""
from haproxyadmin.internal.server import _Server
class _Backend:
"""Class for interacting with a backend in one HAProxy process.
:param hap_process: a :class::`_HAProxyProcess` object.
:param name: backend name.
:type name: ``string``
:param iid: unique proxy id of the backend.
:type iid: ``integer``
"""
def __init__(self, hap_process, name, iid):
self.hap_process = hap_process
self._name = name
self.hap_process_nb = self.hap_process.process_nb
self._iid = iid
@property
def name(self):
"""Return a string which is the name of the backend"""
return self._name
@property
def iid(self):
"""Return Proxy ID"""
data = self.stats_data()
self._iid = data.iid
return self._iid
@property
def process_nb(self):
"""Return the process number of the haproxy process
:rtype: ``int``
"""
return int(self.hap_process_nb)
def stats_data(self):
"""Return stats data
Check documentation of ``stats_data`` method in :class:`_Frontend`.
:rtype: ``utils.CSVLine`` object
"""
# Fetch data using the last known iid
try:
data = self.hap_process.backends_stats(self._iid)[self.name]
except KeyError:
# A lookup on HAProxy with the current id doesn't return
# an object with our name.
# Most likely object got different id due to a reshuffle in conf.
# Thus retrieve all objects to get latest data for the object.
try:
data = self.hap_process.backends_stats()[self.name]
except KeyError:
# The object has gone from running configuration!
# We cant recover from this situation.
raise
return data['stats']
def stats(self):
"""Build dictionary for all statistics reported by HAProxy.
:return: A dictionary with statistics
:rtype: ``dict``
"""
data = self.stats_data()
keys = data.heads
values = data.parts
return dict(zip(keys, values))
def metric(self, name):
data = self.stats_data()
return getattr(data, name)
def command(self, cmd):
"""Send command to HAProxy
:param cmd: command to send
:type cmd: ``string``
:return: the output of the command
:rtype: ``string``
"""
return self.hap_process.command(cmd)
def servers(self, name=None):
"""Return a list of _Server objects for each server of the backend.
:param name: (optional): server name to lookup, defaults to None.
:type name: ``string``
"""
servers = []
return_list = []
servers = self.hap_process.servers_stats(self.name, self.iid)
if name is not None:
if name in servers:
return_list.append(_Server(self,
name,
servers[name].sid))
else:
return []
else:
for _name in servers:
return_list.append(_Server(self,
_name,
servers[_name].sid))
return return_list
|
