[Kimchi-devel] [PATCH] [WoK] Asynchronous UI notification implementation
Daniel Henrique Barboza
dhbarboza82 at gmail.com
Mon Feb 27 20:58:33 UTC 2017
On 02/27/2017 11:23 AM, Aline Manera wrote:
>
>
> On 02/24/2017 10:22 AM, dhbarboza82 at gmail.com wrote:
>> From: Daniel Henrique Barboza <danielhb at linux.vnet.ibm.com>
>>
>> This patch makes backend and UI changes to implement the asynchronous
>> UI notification in WoK.
>>
>> - Backend:
>>
>> A push server was implemented from scratch to manage the opened
>> websocket
>> connections. The push server connects to the /run/woknotifications
>> UNIX socket and broadcasts all messages to all connections.
>>
>> The websocket module is the same module that exists in the Kimchi
>> plug-in. The idea is to remove the module from Kimchi and make it
>> use the module from WoK. ws_proxy initialization was also added
>> in src/wok/server.py.
>>
>> - Frontend:
>>
>> In ui/js/wok.main.js two new functions were added to help the
>> usage of asynchronous notifications in the frontend. The idea:
>> a single websocket is opened per session. This opened websocket
>> will broadcast all incoming messages to all listeners registered.
>> Listeners can be added by the new wok.addNotificationListener()
>> method. This method will clean up any registered listener by
>> itself when the user changes tabs/URL.
>>
>> The single websocket sends heartbeats to the backend side each
>> 30 seconds. No reply from the backend is issued or expected. This
>> heartbeat is just a way to ensure that the browser does not
>> close the connection due to inactivity. This behavior varies from
>> browser to browser but this 30 second heartbeat is more than enough
>> to ensure that the websocket is kept alive.
>>
>> - Working example in User Log:
>>
>> A simple usage is provided in this patch. A change was made in
>> src/wok/reqlogger.py to send an asynchronous notification each
>> time a new log entry is created. In ui/js/wok.user-log.js a
>> websocket listener is added using wok.addNotificationListener()
>> and, for each message that indicates a new user log entry, a
>> refresh in the listing is issued.
>>
>> Signed-off-by: Daniel Henrique Barboza <danielhb at linux.vnet.ibm.com>
>> ---
>> src/wok/model/notifications.py | 18 +++++-
>> src/wok/pushserver.py | 132
>> +++++++++++++++++++++++++++++++++++++++++
>> src/wok/reqlogger.py | 7 ++-
>> src/wok/server.py | 8 ++-
>> src/wok/websocket.py | 123
>> ++++++++++++++++++++++++++++++++++++++
>> ui/js/src/wok.main.js | 38 ++++++++++++
>> ui/js/wok.user-log.js | 6 ++
>> 7 files changed, 327 insertions(+), 5 deletions(-)
>> create mode 100644 src/wok/pushserver.py
>> create mode 100644 src/wok/websocket.py
>>
>> diff --git a/src/wok/model/notifications.py
>> b/src/wok/model/notifications.py
>> index bdb7c78..597eac5 100644
>> --- a/src/wok/model/notifications.py
>> +++ b/src/wok/model/notifications.py
>> @@ -1,7 +1,7 @@
>> #
>> # Project Wok
>> #
>> -# Copyright IBM Corp, 2016
>> +# Copyright IBM Corp, 2016-2017
>> #
>> # This library is free software; you can redistribute it and/or
>> # modify it under the terms of the GNU Lesser General Public
>> @@ -19,12 +19,22 @@
>>
>> from datetime import datetime
>>
>> +from wok import config
>> from wok.exception import NotFoundError, OperationFailed
>> from wok.message import WokMessage
>> +from wok.pushserver import PushServer
>> from wok.utils import wok_log
>>
>>
>> notificationsStore = {}
>> +push_server = None
>> +
>> +
>> +def send_websocket_notification(message):
>> + global push_server
>> +
>> + if push_server:
>> + push_server.send_notification(message)
>>
>>
>> def add_notification(code, args=None, plugin_name=None):
>> @@ -57,7 +67,11 @@ def del_notification(code):
>>
>> class NotificationsModel(object):
>> def __init__(self, **kargs):
>> - pass
>> + global push_server
>> +
>
>> + test_mode = config.config.get('server', 'test').lower() ==
>> 'true'
>> + if not test_mode:
>> + push_server = PushServer()
>
> Why distinguish test mode here? While running on test mode, aka, using
> MockModel, the server should behave the same as on real model.
It makes no sense to enable the push server without websocket support. As
it is now, on Kimchi code, the websocket proxy doesn't initialize in
test_mode. This same design was kept when moving the initialization
to WoK.
I've also experienced conflicts when running the unit tests with the
push server.
The multiple instancing of test_model led to the multiple instancing of
the push_server, causing conflict because all push server instances read
from the same unix socket.
>
>>
>> def get_list(self):
>> global notificationsStore
>> diff --git a/src/wok/pushserver.py b/src/wok/pushserver.py
>> new file mode 100644
>> index 0000000..8993f00
>> --- /dev/null
>> +++ b/src/wok/pushserver.py
>> @@ -0,0 +1,132 @@
>> +#
>> +# Project Wok
>> +#
>> +# Copyright IBM Corp, 2017
>> +#
>> +# This library is free software; you can redistribute it and/or
>> +# modify it under the terms of the GNU Lesser General Public
>> +# License as published by the Free Software Foundation; either
>> +# version 2.1 of the License, or (at your option) any later version.
>> +#
>> +# This library is distributed in the hope that it will be useful,
>> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> +# Lesser General Public License for more details.
>> +#
>> +# You should have received a copy of the GNU Lesser General Public
>> +# License along with this library; if not, write to the Free Software
>> +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> 02110-1301 USA
>> +#
>> +
>> +import cherrypy
>> +import os
>> +import select
>> +import socket
>> +import threading
>> +
>
>> +import websocket
>> +from utils import wok_log
>> +
>
> Use full import path.
>
> import wok.websocket
> from wok.utils import wok_log
ok
>
>> +
>> +BASE_DIRECTORY = '/run'
>
> I think this directory depends on distro settings. Some ones uses
> /var/run
> You will need to get it on build settings. Check config.py.in for
> details.
I've copied this line/logic from Kimchi's serialconsole.py assuming it was a
good way to do it. I'll see if using config.py.in in this case is possible.
We can also discuss if putting it under /run is the choice and perhaps
choose
another path entirely.
>
>> +TOKEN_NAME = 'woknotifications'
>> +
>
> Maybe only 'notifications' under a wok directory is better.
> Just to place all the wok files related to the same directory. I am
> not sure if others files is places on /run but i think there are.
As I've said above, I'm open to suggestions of where to put this unix
socket.
>
>> +
>> +class PushServer(object):
>> +
>> + def set_socket_file(self):
>> + if not os.path.isdir(BASE_DIRECTORY):
>> + try:
>> + os.mkdir(BASE_DIRECTORY)
>> + except OSError:
>> + raise RuntimeError('PushServer base UNIX socket dir
>> %s '
>> + 'not found.' % BASE_DIRECTORY)
>> +
>> + self.server_addr = os.path.join(BASE_DIRECTORY, TOKEN_NAME)
>> +
>> + if os.path.exists(self.server_addr):
>> + try:
>> + os.remove(self.server_addr)
>> + except:
>> + raise RuntimeError('There is an existing connection
>> in %s' %
>> + self.server_addr)
>> +
>> + def __init__(self):
>> + self.set_socket_file()
>> +
>> + websocket.add_proxy_token(TOKEN_NAME, self.server_addr, True)
>> +
>> + self.connections = []
>> +
>> + self.server_running = True
>> + self.server_socket = socket.socket(socket.AF_UNIX,
>> socket.SOCK_STREAM)
>> + self.server_socket.setsockopt(socket.SOL_SOCKET,
>> + socket.SO_REUSEADDR, 1)
>> + self.server_socket.bind(self.server_addr)
>> + self.server_socket.listen(10)
>> + wok_log.info('Push server created on address %s' %
>> self.server_addr)
>> +
>> + self.connections.append(self.server_socket)
>> + cherrypy.engine.subscribe('stop', self.close_server, 1)
>> +
>> + server_loop = threading.Thread(target=self.listen)
>> + server_loop.start()
>> +
>> + def listen(self):
>> + try:
>> + while self.server_running:
>> + read_ready, _, _ = select.select(self.connections,
>> + [], [], 1)
>> + for sock in read_ready:
>> + if not self.server_running:
>> + break
>> +
>> + if sock == self.server_socket:
>> +
>> + new_socket, addr = self.server_socket.accept()
>> + self.connections.append(new_socket)
>> + else:
>> + try:
>> + data = sock.recv(4096)
>> + except:
>> + try:
>> + self.connections.remove(sock)
>> + except ValueError:
>> + pass
>> +
>> + continue
>> + if data and data == 'CLOSE':
>> + sock.send('ACK')
>> + try:
>> + self.connections.remove(sock)
>> + except ValueError:
>> + pass
>> + sock.close()
>> +
>> + except Exception as e:
>> + raise RuntimeError('Exception ocurred in listen() of
>> pushserver '
>> + 'module: %s' % e.message)
>> +
>> + def send_notification(self, message):
>> + for sock in self.connections:
>> + if sock != self.server_socket:
>> + try:
>> + sock.send(message)
>> + except IOError as e:
>> + if 'Broken pipe' in str(e):
>> + sock.close()
>> + try:
>> + self.connections.remove(sock)
>> + except ValueError:
>> + pass
>> +
>> + def close_server(self):
>> + try:
>> + self.server_running = False
>> + self.server_socket.shutdown(socket.SHUT_RDWR)
>> + self.server_socket.close()
>> + os.remove(self.server_addr)
>> + except:
>> + pass
>> + finally:
>> + cherrypy.engine.unsubscribe('stop', self.close_server)
>> diff --git a/src/wok/reqlogger.py b/src/wok/reqlogger.py
>> index 92e155d..1b774e2 100644
>> --- a/src/wok/reqlogger.py
>> +++ b/src/wok/reqlogger.py
>> @@ -1,7 +1,7 @@
>> #
>> # Project Wok
>> #
>> -# Copyright IBM Corp, 2016
>> +# Copyright IBM Corp, 2016-2017
>> #
>> # This library is free software; you can redistribute it and/or
>> # modify it under the terms of the GNU Lesser General Public
>> @@ -34,6 +34,7 @@ from wok.auth import USER_NAME
>> from wok.config import get_log_download_path, paths
>> from wok.exception import InvalidParameter, OperationFailed
>> from wok.message import WokMessage
>> +from wok.model.notifications import send_websocket_notification
>> from wok.stringutils import ascii_dict
>> from wok.utils import remove_old_files
>>
>> @@ -68,6 +69,8 @@ WOK_REQUEST_LOGGER = "wok_request_logger"
>> # AsyncTask handling
>> ASYNCTASK_REQUEST_METHOD = 'TASK'
>>
>> +NEW_LOG_ENTRY_MESSAGE = 'new_log_entry'
>> +
>>
>> def log_request(code, params, exception, method, status, app=None,
>> user=None,
>> ip=None):
>> @@ -114,6 +117,8 @@ def log_request(code, params, exception, method,
>> status, app=None, user=None,
>> ip=ip
>> ).log()
>>
>> + send_websocket_notification(NEW_LOG_ENTRY_MESSAGE)
>> +
>> return log_id
>>
>>
>> diff --git a/src/wok/server.py b/src/wok/server.py
>> index fc2e167..2d823c9 100644
>> --- a/src/wok/server.py
>> +++ b/src/wok/server.py
>> @@ -25,8 +25,7 @@ import logging
>> import logging.handlers
>> import os
>>
>> -from wok import auth
>> -from wok import config
>> +from wok import auth, config, websocket
>> from wok.config import config as configParser
>> from wok.config import WokConfig
>> from wok.control import sub_nodes
>> @@ -159,6 +158,11 @@ class Server(object):
>> cherrypy.tree.mount(WokRoot(model.Model(), dev_env),
>> options.server_root, self.configObj)
>
>> + test_mode = config.config.get('server', 'test').lower() ==
>> 'true'
>> + if not test_mode:
>> + ws_proxy = websocket.new_ws_proxy()
>> + cherrypy.engine.subscribe('exit', ws_proxy.terminate)
>> +
>
> The same question I did before.
See answer above.
>
>> self._load_plugins()
>> cherrypy.lib.sessions.init()
>>
>> diff --git a/src/wok/websocket.py b/src/wok/websocket.py
>> new file mode 100644
>> index 0000000..5d7fb91
>> --- /dev/null
>> +++ b/src/wok/websocket.py
>> @@ -0,0 +1,123 @@
>> +#!/usr/bin/env python2
>> +#
>> +# Project Wok
>> +#
>> +# Copyright IBM Corp, 2017
>> +#
>> +# Code derived from Project Kimchi
>> +#
>> +# This library is free software; you can redistribute it and/or
>> +# modify it under the terms of the GNU Lesser General Public
>> +# License as published by the Free Software Foundation; either
>> +# version 2.1 of the License, or (at your option) any later version.
>> +#
>> +# This library is distributed in the hope that it will be useful,
>> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> +# Lesser General Public License for more details.
>> +#
>> +# You should have received a copy of the GNU Lesser General Public
>> +# License along with this library; if not, write to the Free Software
>> +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> 02110-1301 USA
>> +
>> +import base64
>> +import errno
>> +import os
>> +
>> +from multiprocessing import Process
>> +from websockify import WebSocketProxy
>> +
>> +from config import config, PluginPaths
>> +
>> +
>> +try:
>> + from websockify.token_plugins import TokenFile
>> + tokenFile = True
>> +except ImportError:
>> + tokenFile = False
>> +
>> +try:
>> + from websockify import ProxyRequestHandler as request_proxy
>> +except:
>> + from websockify import WebSocketProxy as request_proxy
>> +
>> +
>> +WS_TOKENS_DIR = os.path.join(PluginPaths('kimchi').state_dir,
>> 'ws-tokens')
>> +
>> +
>> +class CustomHandler(request_proxy):
>> +
>> + def get_target(self, target_plugin, path):
>> + if issubclass(CustomHandler, object):
>> + target = super(CustomHandler,
>> self).get_target(target_plugin,
>> + path)
>> + else:
>> + target = request_proxy.get_target(self, target_plugin,
>> path)
>> +
>> + if target[0] == 'unix_socket':
>> + try:
>> + self.server.unix_target = target[1]
>> + except:
>> + self.unix_target = target[1]
>> + else:
>> + try:
>> + self.server.unix_target = None
>> + except:
>> + self.unix_target = None
>> + return target
>> +
>> +
>> +def new_ws_proxy():
>> + try:
>> + os.makedirs(WS_TOKENS_DIR, mode=0755)
>> + except OSError as e:
>> + if e.errno == errno.EEXIST:
>> + pass
>> +
>> + params = {'listen_host': '127.0.0.1',
>> + 'listen_port': config.get('server', 'websockets_port'),
>> + 'ssl_only': False}
>> +
>> + # old websockify: do not use TokenFile
>> + if not tokenFile:
>> + params['target_cfg'] = WS_TOKENS_DIR
>> +
>> + # websockify 0.7 and higher: use TokenFile
>> + else:
>> + params['token_plugin'] = TokenFile(src=WS_TOKENS_DIR)
>> +
>> + def start_proxy():
>> + try:
>> + server = WebSocketProxy(RequestHandlerClass=CustomHandler,
>> + **params)
>> + except TypeError:
>> + server = CustomHandler(**params)
>> +
>> + server.start_server()
>> +
>> + proc = Process(target=start_proxy)
>> + proc.start()
>> + return proc
>> +
>> +
>> +def add_proxy_token(name, port, is_unix_socket=False):
>> + with open(os.path.join(WS_TOKENS_DIR, name), 'w') as f:
>> + """
>> + From python documentation base64.urlsafe_b64encode(s)
>> + substitutes - instead of + and _ instead of / in the
>> + standard Base64 alphabet, BUT the result can still
>> + contain = which is not safe in a URL query component.
>> + So remove it when needed as base64 can work well without it.
>> + """
>> + name = base64.urlsafe_b64encode(name).rstrip('=')
>> + if is_unix_socket:
>> + f.write('%s: unix_socket:%s' % (name.encode('utf-8'),
>> port))
>> + else:
>> + f.write('%s: localhost:%s' % (name.encode('utf-8'), port))
>> +
>> +
>> +def remove_proxy_token(name):
>> + try:
>> + os.unlink(os.path.join(WS_TOKENS_DIR, name))
>> + except OSError:
>> + pass
>> diff --git a/ui/js/src/wok.main.js b/ui/js/src/wok.main.js
>> index 20c017e..f5031ce 100644
>> --- a/ui/js/src/wok.main.js
>> +++ b/ui/js/src/wok.main.js
>> @@ -29,6 +29,41 @@ wok.getConfig(function(result) {
>> wok.config = {};
>> });
>>
>> +
>> +wok.notificationListeners = {};
>> +wok.addNotificationListener = function(name, func) {
>> + wok.notificationListeners[name] = func;
>> + $(window).one("hashchange", function() {
>> + delete wok.notificationListeners[name];
>> + });
>> +};
>> +
>> +wok.notificationsWebSocket = undefined;
>> +wok.startNotificationWebSocket = function () {
>> + var addr = window.location.hostname + ':' + window.location.port;
>> + var token =
>> wok.urlSafeB64Encode('woknotifications').replace(/=*$/g, "");
>> + var url = 'wss://' + addr + '/websockify?token=' + token;
>> + wok.notificationsWebSocket = new WebSocket(url, ['base64']);
>> +
>> + wok.notificationsWebSocket.onmessage = function(event) {
>> + var message = window.atob(event.data);
>> + for (name in wok.notificationListeners) {
>> + func = wok.notificationListeners[name];
>> + func(message);
>> + }
>> + };
>> +
>> + sessionStorage.setItem('wokNotificationWebSocket', 'true');
>> + var heartbeat = setInterval(function() {
>> + wok.notificationsWebSocket.send(window.btoa('heartbeat'));
>> + }, 30000);
>> +
>> + wok.notificationsWebSocket.onclose = function() {
>> + clearInterval(heartbeat);
>> + };
>> +};
>> +
>> +
>> wok.main = function() {
>> wok.isLoggingOut = false;
>> wok.popable();
>> @@ -395,6 +430,9 @@ wok.main = function() {
>>
>> // Set handler for help button
>> $('#btn-help').on('click', wok.openHelp);
>> +
>> + // start WebSocket
>> + wok.startNotificationWebSocket();
>> };
>>
>> var initUI = function() {
>> diff --git a/ui/js/wok.user-log.js b/ui/js/wok.user-log.js
>> index 0e8fb09..083b6c3 100644
>> --- a/ui/js/wok.user-log.js
>> +++ b/ui/js/wok.user-log.js
>> @@ -153,6 +153,12 @@ wok.initUserLogContent = function() {
>> $("#user-log-grid").bootgrid("search");
>> wok.initUserLogConfigGridData();
>> });
>> +
>
>> + wok.addNotificationListener('userlog', function(message) {
>> + if (message === 'new_log_entry') {
>> + $("#refresh-button").click();
>> + }
>> + });
>
> Backend is sending a notification with 'new_log_entry' and you are
> registering a notification for 'userlog'.
> How is it working?
'userlog' is the identifier of the listener that will be used in the hash
wok.notificationListeners.
>
> Shouldn't the 'name' required by addNotificationListener be
> 'new_log_entry'? So wok would be redirect to the function automatically?
> Why do you need to distinguish the 'new_log_entry' later?
>
> Also, we will need to create a pattern message for notification to
> avoid having a plugin overwriting a notification from another plugin.
Agree. I was aware that this 'new_log_entry' was going to be changed by
something more formal.
>
> That said, my suggestion is: <plugin>_<resource>_<action> which will
> result in something like:
>
> wok_log_create
> kimchi_vms_create
> kimchi_vm_update
> kimchi_vm_start
> ginger_backups_create
> ginger_backup_restore
>
> and so on.
>
> That way, we can automatically add the notification on control/base.py
> which will work for everyone. And then, the plugin just need to
> register the listener on UI.
> Something like:
>
> @model/base.py
> #Collection.index and Resource.index (need to cover both)
> def index(...):
> (...)
> # on sucsess
> notification = "%s_%s_%s" % (plugin_name, resource/collection,
> action)
> send_websocket_notification(notification)
>
> def _generate_action_handler_base(...):
> (...)
> # on success
> notification = "%s_%s_%s" % (plugin_name, resource/collection,
> action)
> send_websocket_notification(notification)
>
> What do you think?
I think we can work with this plugin_name/entity/action format, perhaps
adding
an 'args' field to it. In the case of this patch we would have
'wok/userlog/create'
or something similar.
We need to also consider task handling in this context. We can change
the default
success/failure handles to also automatically report the status to the
UI via
websocket.
In fact, we need to consider a lot of standardization with this feature.
For this patch,
I we can start by doing the action handler changes you've proposed to
implement the
user log changes. I have no problems putting the notification under the
'index' of
both Collection and Resource models too.
Daniel
>
>> };
>>
>> wok.initUserLogWindow = function() {
>
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