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- Committer: Tom Haddon
- Date: 2012-07-26 14:42:58 UTC
- mto: (24.15.1 postgresql)
- mto: This revision was merged to the branch mainline in revision 25.
- Revision ID: tom.haddon@canonical.com-20120726144258-o1li1l9e28vkxiti
Initial try and custom postgresql charm
- files added:
- config.yaml
- hooks/config-changed
- templates
- files modified:
- metadata.yaml
added
removed
hooks/hooks.py
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#!/usr/bin/env python
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import json
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import glob
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import os
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import random
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import re
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import socket
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import string
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import subprocess
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import sys
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import yaml
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from Cheetah.Template import Template
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###############################################################################
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# Supporting functions
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###############################################################################
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#------------------------------------------------------------------------------
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# config_get: Returns a dictionary containing all of the config information
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# Optional parameter: scope
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# scope: limits the scope of the returned configuration to the
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# desired config item.
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#------------------------------------------------------------------------------
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def config_get(scope=None):
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try:
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config_cmd_line = ['config-get']
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if scope is not None:
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config_cmd_line.append(scope)
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config_cmd_line.append('--format=json')
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config_data = json.loads(subprocess.check_output(config_cmd_line))
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except:
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config_data = None
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finally:
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return(config_data)
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#------------------------------------------------------------------------------
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# get_service_port: Convenience function that scans the existing postgresql
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# configuration file and returns a the existing port
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# being used. This is necessary to know which port(s)
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# to open and close when exposing/unexposing a service
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#------------------------------------------------------------------------------
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def get_service_port(postgresql_config_file="/etc/postgresql/9.1/main/postgresql.conf"):
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postgresql_config = load_postgresql_config(postgresql_config_file)
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if postgresql_config is None:
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return(None)
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return(re.findall("port.*=(.*)", haproxy_config))
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#------------------------------------------------------------------------------
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# relation_get: Returns a dictionary containing the relation information
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# Optional parameters: scope, relation_id
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# scope: limits the scope of the returned data to the
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# desired item.
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# unit_name: limits the data ( and optionally the scope )
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# to the specified unit
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#------------------------------------------------------------------------------
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def relation_get(scope=None, unit_name=None):
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try:
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relation_cmd_line = ['relation-get', '--format=json']
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if scope is not None:
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relation_cmd_line.append(scope)
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else:
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relation_cmd_line.append('')
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if unit_name is not None:
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relation_cmd_line.append(unit_name)
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relation_data = json.loads(subprocess.check_output(relation_cmd_line))
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except:
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relation_data = None
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finally:
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return(relation_data)
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#------------------------------------------------------------------------------
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# apt_get_install( package ): Installs a package
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#------------------------------------------------------------------------------
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def apt_get_install(packages=None):
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if packages is None:
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return(False)
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cmd_line = ['apt-get', '-y', 'install', '-qq']
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cmd_line.append(packages)
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return(subprocess.call(cmd_line))
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#------------------------------------------------------------------------------
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# create_postgresql_config: Creates the postgresql.conf file
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#------------------------------------------------------------------------------
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def create_postgresql_config():
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# Send config data to the template
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# Return it as pg_config
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pg_config = Template(open("templates/postgresql.conf.tmp").read(), config_data)
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with open(postgresql_config, 'w') as postgres_config:
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postgres_config.write(pg_config)
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#------------------------------------------------------------------------------
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# load_postgresql_config: Convenience function that loads (as a string) the
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# current postgresql configuration file.
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# Returns a string containing the postgresql config or
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# None
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#------------------------------------------------------------------------------
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def load_postgresql_config():
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if os.path.isfile(postgresql_config):
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return(open(postgresql_config).read())
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else:
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return(None)
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#------------------------------------------------------------------------------
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# open_port: Convenience function to open a port in juju to
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# expose a service
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#------------------------------------------------------------------------------
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def open_port(port=None, protocol="TCP"):
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if port is None:
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return(None)
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return(subprocess.call(['/usr/bin/open-port', "%d/%s" % \
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(int(port), protocol)]))
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#------------------------------------------------------------------------------
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# close_port: Convenience function to close a port in juju to
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# unexpose a service
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#------------------------------------------------------------------------------
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def close_port(port=None, protocol="TCP"):
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if port is None:
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return(None)
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return(subprocess.call(['/usr/bin/close-port', "%d/%s" % \
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(int(port), protocol)]))
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#------------------------------------------------------------------------------
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# update_service_ports: Convenience function that evaluate the old and new
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# service ports to decide which ports need to be
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# opened and which to close
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#------------------------------------------------------------------------------
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def update_service_ports(old_service_ports=None, new_service_ports=None):
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if old_service_ports is None or new_service_ports is None:
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return(None)
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for port in old_service_ports:
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if port not in new_service_ports:
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close_port(port)
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for port in new_service_ports:
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if port not in old_service_ports:
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open_port(port)
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#------------------------------------------------------------------------------
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# pwgen: Generates a random password
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# pwd_length: Defines the length of the password to generate
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# default: 20
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#------------------------------------------------------------------------------
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def pwgen(pwd_length=20):
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alphanumeric_chars = [l for l in (string.letters + string.digits) \
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if l not in 'Iil0oO1']
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random_chars = [random.choice(alphanumeric_chars) \
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for i in range(pwd_length)]
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return(''.join(random_chars))
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#------------------------------------------------------------------------------
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# construct_haproxy_config: Convenience function to write haproxy.cfg
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# haproxy_globals, haproxy_defaults,
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# haproxy_monitoring, haproxy_services
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# are all strings that will be written without
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# any checks.
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# haproxy_monitoring and haproxy_services are
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# optional arguments
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#------------------------------------------------------------------------------
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def construct_haproxy_config(haproxy_globals=None,
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haproxy_defaults=None,
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haproxy_monitoring=None,
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haproxy_services=None):
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if haproxy_globals is None or \
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haproxy_defaults is None:
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return(None)
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with open(default_haproxy_config, 'w') as haproxy_config:
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haproxy_config.write(haproxy_globals)
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haproxy_config.write("\n")
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haproxy_config.write("\n")
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haproxy_config.write(haproxy_defaults)
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haproxy_config.write("\n")
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haproxy_config.write("\n")
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if haproxy_monitoring is not None:
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haproxy_config.write(haproxy_monitoring)
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haproxy_config.write("\n")
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haproxy_config.write("\n")
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if haproxy_services is not None:
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haproxy_config.write(haproxy_services)
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haproxy_config.write("\n")
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haproxy_config.write("\n")
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#------------------------------------------------------------------------------
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# service_haproxy: Convenience function to start/stop/restart/reload
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# the haproxy service
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#------------------------------------------------------------------------------
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def service_haproxy(action=None, haproxy_config=default_haproxy_config):
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if action is None or haproxy_config is None:
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return(None)
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elif action == "check":
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retVal = subprocess.call(\
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['/usr/sbin/haproxy', '-f', haproxy_config, '-c'])
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if retVal == 1:
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return(False)
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elif retVal == 0:
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return(True)
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else:
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return(False)
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else:
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retVal = subprocess.call(['service', 'haproxy', action])
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if retVal == 0:
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return(True)
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else:
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return(False)
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###############################################################################
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# Hook functions
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###############################################################################
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def install_hook():
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return (apt_get_install("postgresql-%s" % version) == True)
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def config_changed():
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current_service_port = get_service_port()
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create_postgresql_config()
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updated_service_port = config_data["listen_port"]
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update_service_port(current_service_port, updated_service_port)
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service_postgresql("reload")
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def start_hook():
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if service_postgresql("status"):
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return(service_postgresql("restart"))
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else:
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return(service_postgresql("start"))
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def stop_hook():
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if service_postgresql("status"):
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return(service_postgresql("stop"))
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def reverseproxy_interface(hook_name=None):
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if hook_name is None:
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return(None)
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if hook_name == "changed":
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config_changed()
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def website_interface(hook_name=None):
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if hook_name is None:
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return(None)
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my_fqdn = socket.getfqdn(socket.gethostname())
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default_port = 80
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relation_data = relation_get()
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if hook_name == "joined":
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subprocess.call(['relation-set', 'port=%d' % \
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default_port, 'hostname=%s' % my_fqdn])
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elif hook_name == "changed":
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if 'is-proxy' in relation_data:
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service_name = "%s__%d" % \
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(relation_data['hostname'], relation_data['port'])
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open("%s/%s.is.proxy" % \
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(default_haproxy_service_config_dir, service_name), 'a').close()
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###############################################################################
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# Global variables
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###############################################################################
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config_data = config_get()
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version = config_data['version']
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cluster_name = config_data['cluster_name']
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postgresql_config_dir = "/etc/postgresql"
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postgresql_config = "%s/%s/%s/postgresql.conf" % (version, cluster_name, postgreql_config_dir)
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postgresql_service_config_dir = "/var/run/postgresql"
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hook_name = os.path.basename(sys.argv[0])
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###############################################################################
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# Main section
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###############################################################################
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if hook_name == "install":
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install_hook()
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elif hook_name == "config-changed":
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config_changed()
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elif hook_name == "start":
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start_hook()
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elif hook_name == "stop":
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stop_hook()
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elif hook_name == "reverseproxy-relation-broken":
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config_changed()
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elif hook_name == "reverseproxy-relation-changed":
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reverseproxy_interface("changed")
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elif hook_name == "website-relation-joined":
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website_interface("joined")
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elif hook_name == "website-relation-changed":
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website_interface("changed")
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else:
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print "Unknown hook"
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sys.exit(1)
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