Added plugins management to host handler

from sjrpc.utils import pass_connection, threadless

from sjrpc.core.protocols import TunnelProtocol

from sjrpc.core.exceptions import RpcError

from cloudcontrol.common.client.tags import Tag, tag_inspector

from cloudcontrol.common.client.tags import Tag, tag_inspector, TagDB

from cloudcontrol.common.client.plugins import Base as BasePlugin

from cloudcontrol.common.jobs import JobsManager, JobsStore

from cloudcontrol.common.helpers.logger import patch_logging; patch_logging()

from cloudcontrol.node.host import tags

from cloudcontrol.node.host.jobs import NodeJobsManagerInterface, ScriptJob

from cloudcontrol.node.host.plugins import PluginMethodJob, Plugin

logger = logging.getLogger(__name__)

            job_purge=self.job_purge,

            job_attachment=self.job_attachment,

            script_run=self.script_run,

            plugin_install=self.plugin_install,

            plugin_uninstall=self.plugin_uninstall,

            plugin_run=self.plugin_run

        ))

        # running shells

        self.shells = dict()

        self.jobs_manager = JobsManager(logger, NodeJobsManagerInterface(self),

                                       JobsStore(self.main.config.jobs_store_path))

        #: loaded plugins

        self.plugins = {}  # plugin name -> plugin object

    def stop(self):

        # kill all currently running shells

        for shell in self.shells.values():

        :param name: attachement name

        """

        return self.jobs_manager.get(job_id).read_attachment(name)

    @pass_connection

    def plugin_install(self, conn, sha1, name):

        # check if plugin is not already loaded and upgrade it if the sha1 hash

        # has changed:

        if name in self.plugins:

            if self.plugins[name].sha1 != sha1:

                self.plugins[name].uninstall()

                del self.plugins[name]

            else:

                return

        # get plugin from server:

        sha1_get, content = conn.call('plugin_get', name)

        if sha1 != sha1_get:

            raise RuntimeError('Requested sha1 is not available on the server')

        # load the plugin:

        plugin_logger = logger.getChild('plugin.%s' % name)

        self.plugins[name] = Plugin(plugin_logger, TagDB(self.tag_db),

                                    name, sha1, content)

    def plugin_uninstall(self, name):

        plugin = self.plugins.pop(name, None)

        if plugin is None:

            raise KeyError('Plugin %r is not running' % name)

        plugin.uninstall()

    def plugin_run(self, name, method, owner, **kwargs):

        if name not in self.plugins:

            raise KeyError('Plugin %r is not running' % name)

        try:

            func = self.plugins[name].methods[method]

        except KeyError:

            raise KeyError('Unknown method %r' % method)

        return self.jobs_manager.spawn(PluginMethodJob, owner, settings=dict(

            plugin_name=name,

            method_name=method,

            method=func,

            method_kwargs=kwargs,

        )).id