install: Introduce installer framework ipapython.install

https://fedorahosted.org/freeipa/ticket/4468

Reviewed-By: Martin Basti <mbasti@redhat.com>

1 files changed, 115 insertions, 0 deletions

diff --git a/ipapython/install/common.py b/ipapython/install/common.py
new file mode 100644
index 000000000..799ce5009
--- /dev/null
+++ b/ipapython/install/common.py
@@ -0,0 +1,115 @@
+#
+# Copyright (C) 2015  FreeIPA Contributors see COPYING for license
+#
+
+"""
+Common stuff.
+"""
+
+import traceback
+
+from . import core
+from .util import from_
+
+__all__ = ['step', 'Installable', 'Interactive', 'Continuous', 'installer',
+           'uninstaller']
+
+
+def step():
+    def decorator(func):
+        cls = core.Component(Step)
+        cls._installer = staticmethod(func)
+        return cls
+
+    return decorator
+
+
+class Installable(core.Configurable):
+    """
+    Configurable which does install or uninstall.
+    """
+
+    uninstalling = core.Property(False)
+
+    def _get_components(self):
+        components = super(Installable, self)._get_components()
+        if self.uninstalling:
+            components = reversed(list(components))
+        return components
+
+    def _configure(self):
+        if self.uninstalling:
+            return self._uninstall()
+        else:
+            return self._install()
+
+    def _install(self):
+        assert not hasattr(super(Installable, self), '_install')
+
+        return super(Installable, self)._configure()
+
+    def _uninstall(self):
+        assert not hasattr(super(Installable, self), '_uninstall')
+
+        return super(Installable, self)._configure()
+
+
+class Step(Installable):
+    @property
+    def parent(self):
+        raise AttributeError('parent')
+
+    def _install(self):
+        for nothing in self._installer(self.parent):
+            yield from_(super(Step, self)._install())
+
+    @staticmethod
+    def _installer(obj):
+        yield
+
+    def _uninstall(self):
+        for nothing in self._uninstaller(self.parent):
+            yield from_(super(Step, self)._uninstall())
+
+    @staticmethod
+    def _uninstaller(obj):
+        yield
+
+    @classmethod
+    def uninstaller(cls, func):
+        cls._uninstaller = staticmethod(func)
+        return cls
+
+
+class Interactive(core.Configurable):
+    interactive = core.Property(False)
+
+
+class Continuous(core.Configurable):
+    def _handle_exception(self, exc_info):
+        try:
+            super(Continuous, self)._handle_exception(exc_info)
+        except BaseException as e:
+            self.log.debug(traceback.format_exc())
+            if isinstance(e, Exception):
+                self.log.error("%s", e)
+
+
+def installer(cls):
+    class Installer(cls, Installable):
+        def __init__(self, **kwargs):
+            super(Installer, self).__init__(uninstalling=False,
+                                            **kwargs)
+    Installer.__name__ = 'installer({0})'.format(cls.__name__)
+
+    return Installer
+
+
+def uninstaller(cls):
+    class Uninstaller(Continuous, cls, Installable):
+        def __init__(self, **kwargs):
+            super(Uninstaller, self).__init__(uninstalling=True,
+                                              **kwargs)
+    Uninstaller.__name__ = 'uninstaller({0})'.format(cls.__name__)
+
+    return Uninstaller