From: Leandro Lucarella <llucax@gmail.com>
Date: Mon, 16 Jun 2008 18:43:45 +0000 (-0300)
Subject: Use a plug-in architecture for services (refs #27).
X-Git-Url: https://git.llucax.com/software/pymin.git/commitdiff_plain/fac20bd5c930ab027e9c097f34bf50714f8a53d5

Use a plug-in architecture for services (refs #27).

Service modules are loaded dinamically using the imp module. The config.py
file is simplified to avoid the need of defining pymind command handlers
"tree" in the configuration file.
---

diff --git a/config.py b/config.py
index aae79c1..aa3e5eb 100644
--- a/config.py
+++ b/config.py
@@ -8,7 +8,6 @@ logging.basicConfig(
         datefmt = '%a, %d %b %Y %H:%M:%S',
 )
 
-from pymin.services import *
 from pymin.dispatcher import Handler
 from os.path import join
 
@@ -17,67 +16,64 @@ pickle_path = join(base_path, 'pickle')
 # FIXME, this should be specific for each service
 config_path = join(base_path, 'config')
 
-class Root(Handler):
-
-    def __init__(self):
-        try:
-            f = file("/proc/sys/net/ipv4/ip_forward","w")
-            f.write("1")
-            f.close()
-        except (IOError, OSError), e:
-            print "Can't set ip_forward:", e
-        #self.ip.device_up_hook(self.dns)
-
-    firewall = FirewallHandler(
-        pickle_dir = join(pickle_path, 'firewall'),
-        config_dir = join(config_path, 'firewall'))
-
-    nat = NatHandler(pickle_dir = join(pickle_path, 'nat'))
-
-    ppp = PppHandler(
-        pickle_dir = join(pickle_path, 'ppp'),
-        config_dir = {
-            'pap-secrets':  join(config_path, 'ppp'),
-            'chap-secrets': join(config_path, 'ppp'),
-            'options.X':    join(config_path, 'ppp'),
-            'nameX':        join(config_path, 'ppp', 'peers'),
-        })
-
-    vpn = VpnHandler(
-         pickle_dir = join(pickle_path, 'vpn'),
-         config_dir = join(config_path, 'vpn'))
-
-    ip = IpHandler(
-        pickle_dir = join(pickle_path, 'ip'),
-        config_dir = join(config_path, 'ip'))
-
-    dns = DnsHandler(
-        pickle_dir = join(pickle_path, 'dns'),
-        config_dir = {
-            'named.conf': join(config_path, 'dns'),
-            'zoneX.zone': join(config_path, 'dns', 'zones'),
-        })
-
-    dhcp = DhcpHandler(
-        pickle_dir = join(pickle_path, 'dhcp'),
-        config_dir = join(config_path, 'dhcp'))
-
-    proxy = ProxyHandler(
-        pickle_dir = join(pickle_path, 'proxy'),
-        config_dir = join(config_path, 'proxy'))
-
-    vrrp = VrrpHandler(
-        pickle_dir = join(pickle_path, 'vrrp'),
-        config_dir = join(config_path, 'vrrp'),
-        pid_dir    = join(config_path, 'vrrp', 'run'))
-
-    vpn = VpnHandler(
-        pickle_dir = join(pickle_path, 'vpn'),
-        config_dir = join(config_path, 'vpn'))
-
-    #qos = QoSHandler(
-    #    pickle_dir = join(pickle_path, 'qos'),
-    #    config_dir = join(config_path, 'qos'))
+try:
+    f = file("/proc/sys/net/ipv4/ip_forward","w")
+    f.write("1")
+    f.close()
+except (IOError, OSError), e:
+    print "Can't set ip_forward:", e
+
+class firewall:
+    pickle_dir = join(pickle_path, 'firewall')
+    config_dir = join(config_path, 'firewall')
+
+class nat:
+    pickle_dir = join(pickle_path, 'nat')
+
+class ppp:
+    pickle_dir = join(pickle_path, 'ppp')
+    config_dir = {
+        'pap-secrets':  join(config_path, 'ppp'),
+        'chap-secrets': join(config_path, 'ppp'),
+        'options.X':    join(config_path, 'ppp'),
+        'nameX':        join(config_path, 'ppp', 'peers'),
+    }
+
+class vpn:
+     pickle_dir = join(pickle_path, 'vpn')
+     config_dir = join(config_path, 'vpn')
+
+class ip:
+    pickle_dir = join(pickle_path, 'ip')
+    config_dir = join(config_path, 'ip')
+
+class dns:
+    pickle_dir = join(pickle_path, 'dns')
+    config_dir = {
+        'named.conf': join(config_path, 'dns'),
+        'zoneX.zone': join(config_path, 'dns', 'zones'),
+    }
+
+class dhcp:
+    pickle_dir = join(pickle_path, 'dhcp')
+    config_dir = join(config_path, 'dhcp')
+
+class proxy:
+    pickle_dir = join(pickle_path, 'proxy')
+    config_dir = join(config_path, 'proxy')
+
+class vrrp:
+    pickle_dir = join(pickle_path, 'vrrp')
+    config_dir = join(config_path, 'vrrp')
+    pid_dir    = join(config_path, 'vrrp', 'run')
+
+class vpn:
+    pickle_dir = join(pickle_path, 'vpn')
+    config_dir = join(config_path, 'vpn')
+
+class qos:
+    pickle_dir = join(pickle_path, 'qos')
+    config_dir = join(config_path, 'qos')
 
 bind_addr = \
 (
@@ -85,3 +81,7 @@ bind_addr = \
     9999, # Port
 )
 
+services = 'firewall nat ppp vpn ip dns dhcp proxy vrrp qos'.split()
+
+services_dirs = ['pymin/services']
+
diff --git a/pymin/services/__init__.py b/pymin/services/__init__.py
index 7620197..1828fb4 100644
--- a/pymin/services/__init__.py
+++ b/pymin/services/__init__.py
@@ -1,12 +1,19 @@
 # vim: set encoding=utf-8 et sw=4 sts=4 :
 
-from pymin.services.dhcp import DhcpHandler
-from pymin.services.dns import DnsHandler
-from pymin.services.firewall import FirewallHandler
-from pymin.services.nat import NatHandler
-from pymin.services.ip import IpHandler
-from pymin.services.proxy import ProxyHandler
-from pymin.services.vrrp import VrrpHandler
-from pymin.services.ppp import PppHandler
-from pymin.services.qos import QoSHandler
-from pymin.services.vpn import VpnHandler
+import imp
+
+class LoadError(ImportError):
+    pass
+
+def load_service(name, search_paths):
+    try:
+        (fp, path, desc) = imp.find_module(name, search_paths)
+    except ImportError:
+        raise LoadError('module "%s" not found' % name)
+
+    try:
+        return imp.load_module(name, fp, path, desc)
+    finally:
+        if fp:
+            fp.close()
+
diff --git a/pymin/services/dhcp/__init__.py b/pymin/services/dhcp/__init__.py
index b5bf6f3..1c6a919 100644
--- a/pymin/services/dhcp/__init__.py
+++ b/pymin/services/dhcp/__init__.py
@@ -9,7 +9,12 @@ from pymin.services.util import Restorable, ConfigWriter, InitdHandler, \
                                 TransactionalHandler, ParametersHandler, \
                                 DictSubHandler, ReloadHandler
 
-__all__ = ('DhcpHandler',)
+__all__ = ('DhcpHandler', 'get_service')
+
+
+def get_service(config):
+    return DhcpHandler(config.dhcp.pickle_dir, config.dhcp.config_dir)
+
 
 class Host(Sequence):
     r"""Host(name, ip, mac) -> Host instance :: Class representing a host.
diff --git a/pymin/services/dns/__init__.py b/pymin/services/dns/__init__.py
index 0576cd0..c3cf03e 100644
--- a/pymin/services/dns/__init__.py
+++ b/pymin/services/dns/__init__.py
@@ -11,7 +11,12 @@ from pymin.services.util import Restorable, ConfigWriter, InitdHandler, \
                                 TransactionalHandler, ParametersHandler, \
                                 DictComposedSubHandler, DictSubHandler, call
 
-__all__ = ('DnsHandler',)
+__all__ = ('DnsHandler', 'get_service')
+
+
+def get_service(config):
+    return DnsHandler(config.dns.pickle_dir, config.dns.config_dir)
+
 
 class Host(Sequence):
     def __init__(self, name, ip):
diff --git a/pymin/services/firewall/__init__.py b/pymin/services/firewall/__init__.py
index 0ab2b4c..7b17c23 100644
--- a/pymin/services/firewall/__init__.py
+++ b/pymin/services/firewall/__init__.py
@@ -14,7 +14,12 @@ from pymin.dispatcher import Handler, handler, HandlerError
 from pymin.services.util import Restorable, ConfigWriter, ServiceHandler, \
                                 TransactionalHandler, ListSubHandler
 
-__all__ = ('FirewallHandler',)
+__all__ = ('FirewallHandler', 'get_service')
+
+
+def get_service(config):
+    return FirewallHandler(config.firewall.pickle_dir, config.firewall.config_dir)
+
 
 class UpOneOf(OneOf):
     def validate_python(self, value, state):
diff --git a/pymin/services/ip/__init__.py b/pymin/services/ip/__init__.py
index 86551f4..54ee30b 100644
--- a/pymin/services/ip/__init__.py
+++ b/pymin/services/ip/__init__.py
@@ -12,7 +12,11 @@ from pymin.services.util import Restorable, ConfigWriter, InitdHandler, \
                                 DictComposedSubHandler, ListSubHandler, \
                                 Device, Address, ExecutionError
 
-__all__ = ('IpHandler',)
+__all__ = ('IpHandler', 'get_service')
+
+
+def get_service(config):
+    return IpHandler(config.ip.pickle_dir, config.ip.config_dir)
 
 
 class Hop(Sequence):
diff --git a/pymin/services/nat/__init__.py b/pymin/services/nat/__init__.py
index 34d5b0d..3afc997 100644
--- a/pymin/services/nat/__init__.py
+++ b/pymin/services/nat/__init__.py
@@ -9,7 +9,12 @@ from pymin.services.util import Restorable, ConfigWriter, RestartHandler, \
                                 ReloadHandler, TransactionalHandler, \
                                 ServiceHandler, ListSubHandler, call
 
-__all__ = ('NatHandler',)
+__all__ = ('NatHandler', 'get_service')
+
+
+def get_service(config):
+    return NatHandler(config.nat.pickle_dir)
+
 
 class PortForward(Sequence):
     r"""PortForward(dev, protocol, port, dst[, dst_port[, ...]]) -> PortForward.
diff --git a/pymin/services/ppp/__init__.py b/pymin/services/ppp/__init__.py
index 6ee9f5a..7f5a143 100644
--- a/pymin/services/ppp/__init__.py
+++ b/pymin/services/ppp/__init__.py
@@ -11,7 +11,12 @@ from pymin.dispatcher import Handler, handler, HandlerError
 from pymin.services.util import Restorable, ConfigWriter, ReloadHandler, \
                                 TransactionalHandler, DictSubHandler, call
 
-__all__ = ('PppHandler',)
+__all__ = ('PppHandler', 'get_service')
+
+
+def get_service(config):
+    return PppHandler(config.ppp.pickle_dir, config.ppp.config_dir)
+
 
 class ConnectionError(HandlerError, KeyError):
     r"""
diff --git a/pymin/services/proxy/__init__.py b/pymin/services/proxy/__init__.py
index 5ab624b..448f568 100644
--- a/pymin/services/proxy/__init__.py
+++ b/pymin/services/proxy/__init__.py
@@ -11,7 +11,13 @@ from pymin.services.util import Restorable, ConfigWriter, InitdHandler, \
 
 import crypt
 
-__all__ = ('ProxyHandler',)
+
+__all__ = ('ProxyHandler', 'get_service')
+
+
+def get_service(config):
+    return ProxyHandler(config.proxy.pickle_dir, config.proxy.config_dir)
+
 
 class Host(Sequence):
     def __init__(self,ip):
diff --git a/pymin/services/qos/__init__.py b/pymin/services/qos/__init__.py
index b583d4d..d021d68 100644
--- a/pymin/services/qos/__init__.py
+++ b/pymin/services/qos/__init__.py
@@ -10,7 +10,12 @@ from pymin.services.util import Restorable, ConfigWriter, InitdHandler, \
                                 get_network_devices, ListComposedSubHandler, \
                                 DictComposedSubHandler, ExecutionError
 
-__all__ = ('QoSHandler',)
+__all__ = ('QoSHandler', 'get_service')
+
+
+def get_service(config):
+    return QoSHandler(config.qos.pickle_dir, config.qos.config_dir)
+
 
 class DeviceError(HandlerError):
 
diff --git a/pymin/services/vpn/__init__.py b/pymin/services/vpn/__init__.py
index f3b9f95..066e8fc 100644
--- a/pymin/services/vpn/__init__.py
+++ b/pymin/services/vpn/__init__.py
@@ -13,6 +13,13 @@ from pymin.services.util import Restorable, ConfigWriter, InitdHandler, \
                                 TransactionalHandler, DictSubHandler, DictComposedSubHandler, call, ExecutionError
 
 
+__all__ = ('VpnHandler', 'get_service')
+
+
+def get_service(config):
+    return VpnHandler(config.vpn.pickle_dir, config.vpn.config_dir)
+
+
 class Host(Sequence):
     def __init__(self, vpn_src, ip, vpn_src_net, key):
         self.name = vpn_src
diff --git a/pymin/services/vrrp/__init__.py b/pymin/services/vrrp/__init__.py
index f957bb4..9b4c0e6 100644
--- a/pymin/services/vrrp/__init__.py
+++ b/pymin/services/vrrp/__init__.py
@@ -8,7 +8,12 @@ from pymin.services.util import Restorable, TransactionalHandler, \
 # Logger
 import logging ; log = logging.getLogger('pymin.services.vrrp')
 
-__all__ = ('VrrpHandler',)
+__all__ = ('VrrpHandler', 'get_service')
+
+
+def get_service(config):
+    return VrrpHandler(config.vrrp.pickle_dir, config.vrrp.config_dir)
+
 
 # FIXME the the command should not use new parameters unless commit where called
 #       i.e. integrate commit with procman to update internal procman parameters.
diff --git a/pymind b/pymind
index a04307d..2f428b5 100755
--- a/pymind
+++ b/pymind
@@ -1,8 +1,29 @@
 #!/usr/bin/env python
 # vim: set encoding=utf-8 et sw=4 sts=4 :
 
+import sys
 from pymin.pymindaemon import PyminDaemon
+from pymin.dispatcher import Handler
+from pymin.services import load_service, LoadError
 import config
 
-PyminDaemon(config.Root(), config.bind_addr).run()
+class Root(Handler):
+    pass
+
+def build_root(config):
+    # TODO check services dependencies
+    services = dict()
+    for service in config.services:
+        try:
+            s = load_service(service, config.services_dirs)
+        except LoadError, e:
+            sys.stderr.write("Can't find service called '%s'\n" % service)
+            sys.exit(1)
+        services[service] = s
+    root = Root()
+    for name, service in services.items():
+        setattr(root, name, service.get_service(config))
+    return root
+
+PyminDaemon(build_root(config), config.bind_addr).run()