Document TFW message format in README

Networking refactor

.drone.yml

@@ -0,0 +1,13 @@
+pipeline:
+  build:
+    image: eu.gcr.io/avatao-public/docker:el7
+    volumes:
+      - /etc/docker:/etc/docker:ro
+      - /root/.docker:/root/.docker:ro
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+    commands:
+      - docker build --pull -t eu.gcr.io/avatao-challengestore/tutorial-framework:${DRONE_TAG} .
+      - docker push eu.gcr.io/avatao-challengestore/tutorial-framework:${DRONE_TAG}
+    when:
+      event: 'tag'
+      branch: refs/tags/egyptianmau-20*

.pyenvrc

@@ -1,4 +0,0 @@
-export PYENV_ROOT="$HOME/.pyenv"
-export PATH="$PYENV_ROOT/bin:$PATH"
-eval "$(pyenv init -)"
-eval "$(pyenv virtualenv-init -)"

.pylintrc

@@ -0,0 +1,5 @@
+[TYPECHECK]
+
+ignored-modules = zmq
+max-line-length = 150
+disable = missing-docstring, too-few-public-methods

Dockerfile

@@ -39,30 +39,30 @@ ENV PYTHONPATH="/usr/local/lib/"                                           \
     TFW_HISTFILE="/home/${AVATAO_USER}/.bash_history"                      \
     PROMPT_COMMAND="history -a"
 
-RUN echo "shopt -s cmdhist\n"                 \
+COPY bashrc /tmp
-         "shopt -s histappend\n"              \
+RUN echo "export HISTFILE=${TFW_HISTFILE}\n" >> /tmp/bashrc &&\
-         "unset HISTCONTROL\n"                \
+    cat /tmp/bashrc >> /home/${AVATAO_USER}/.bashrc
-         "export HISTFILE=$TFW_HISTFILE\n"    \
-         "export HISTFILESIZE=1000\n"         \
-         "export HISTSIZE=1000\n"             \
-         'PROMPT_COMMAND="history -a"\n'      \
-    >> /home/${AVATAO_USER}/.bashrc
 
 COPY supervisor/supervisord.conf ${TFW_SUPERVISORD_CONF}
 COPY nginx/nginx.conf ${TFW_NGINX_CONF}
 COPY nginx/default.conf ${TFW_NGINX_DEFAULT}
-COPY lib ${TFW_LIB_DIR}
+COPY nginx/components/ ${TFW_NGINX_COMPONENTS}
+COPY lib LICENSE ${TFW_LIB_DIR}
 
-ONBUILD ARG BUILD_CONTEXT="."
+RUN for dir in "${TFW_LIB_DIR}" "/etc/nginx" "/etc/supervisor"; do \
+        chown -R root:root "$dir" && chmod -R 700 "$dir";          \
+    done
+
+ONBUILD ARG BUILD_CONTEXT="solvable"
 ONBUILD ARG NOFRONTEND=""
 
-ONBUILD COPY ${BUILD_CONTEXT}/nginx/components/ ${TFW_NGINX_COMPONENTS}
+ONBUILD COPY ${BUILD_CONTEXT}/nginx/ ${TFW_NGINX_COMPONENTS}
-ONBUILD COPY ${BUILD_CONTEXT}/supervisor/components/ ${TFW_SUPERVISORD_COMPONENTS}
+ONBUILD COPY ${BUILD_CONTEXT}/supervisor/ ${TFW_SUPERVISORD_COMPONENTS}
 
-ONBUILD RUN chown -R ${AVATAO_USER} /var/log/nginx /var/lib/nginx                                          &&\
+ONBUILD RUN for f in "${TFW_NGINX_DEFAULT}" ${TFW_NGINX_COMPONENTS}/*.conf; do                               \
-            for f in "${TFW_NGINX_DEFAULT}" ${TFW_NGINX_COMPONENTS}/*.conf; do                               \
                 envsubst "$(printenv | cut -d= -f1 | grep TFW_ | sed -e 's/^/$/g')" < $f > $f~ && mv $f~ $f ;\
             done
+ONBUILD VOLUME ["/etc/nginx", "/var/lib/nginx", "/var/log/nginx"]
 
 ONBUILD COPY ${BUILD_CONTEXT}/frontend /data/
 ONBUILD RUN test -z "${NOFRONTEND}" && cd /data && yarn install --frozen-lockfile || :

LICENSE

@@ -0,0 +1,12 @@
+AVATAO CONFIDENTIAL
+
+Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+All Rights Reserved.
+
+All source code, configuration files and documentation contained herein
+is, and remains the exclusive property of Avatao.com Innovative Learning Kft.
+The intellectual and technical concepts contained herein are proprietary 
+to Avatao.com Innovative Learning Kft. and are protected by trade secret
+or copyright law. Dissemination of this information or reproduction of
+this material is strictly forbidden unless prior written permission is
+obtained from Avatao.com Innovative Learning Kft.

README.md

@@ -1,12 +1,83 @@
 # baseimage-tutorial-framework
 
-This is the beating heart of TFW – the Docker baseimage consisting of the backend internals of the framework.
+This is the beating heart of TFW – the Docker baseimage containing the internals of the framework.
 
-All tutorial-framework challenges are child images of this one: their `Dockerfile`s all begin with `FROM avatao/tutorial-framework`.
+Every tutorial-framework based challenge has a `solvable` Docker image based on this one: their `Dockerfile`s begin with `FROM eu.gcr.io/avatao-challengestore/tutorial-framework`.
+Note that TFW is not avaliable on Docker Hub due to legal reasons and is only accessible through local builds (dont't worry, we've got you covered with build scripts in the `test-tutorial-framework` repo).
 
 This document explains the general concepts of TFW and should be the first thing you read before getting started with development.
 
 For more on building and running you should consult the `test-tutorial-framework` repo.
 
 ## The framework
-*... in progress ...*
+
+The goal of the tutorial-framework is to help content developers in creating interactive tutorials for the Avatao platform.
+
+To make this possible TFW implements a robust messaging system and provides several pre-written components built upon it, such as a file editor and a terminal (both running in your browser).
+
+The foundation of the whole framework is the messaging system connecting the frontend with the backend.
+Frontend components use websockets to connect to the TFW server, to which you can hook several *event handlers* defining how to handle specific messages.
+
+![TFW architecture](docs/tfw_architecture.png)
+
+### Event handlers
+
+Imagine event handlers as callbacks that are invoked when TFW receives a specific type of message. For instance you could send a message to the framework when the user does something of note.
+
+This allows you to define actions triggered on the backend when the user presses a button on the frontend, moves the cursor to a specific area or anything like that.
+
+Event handlers use ZeroMQ to connect to the framework. Due to this they are as loosely-coupled as possible: usually they are running in separate processes and only communicate with TFW through ZMQ.
+
+Our pre-made event handlers are written in Python3, but you can write event handlers in any language that has ZeroMQ bindings (this means virtually any language).
+
+This makes the framework really flexible: you can demonstrate the concepts you want to in any language while using the same set of tools provided by TFW.
+Inside Avatao this means that any of the content teams can use the framework with ease.
+
+### FSM
+
+Another unique feature of the framework is the FSM – finite state machine – representing the state of your challenge.
+This allows you to track users progressing with the tasks you've defined for them to complete.
+
+For instance you could represent whether the user managed to create a malicious user with a state called `user_registered` and subscribe callbacks to events regarding that state (like entering or leaving).
+
+You could create challenges that can be completed in several different ways: imagine a state called `challenge_complete`, which represents when the challenge is completed. Several series of actions (triggers) could lead to this state.
+
+This enables you to guide your users through the experience you've envisioned with your tutorial.
+We can provide a whole new level of interactivity in our challenges because we know what the user is doing.
+This includes context-dependent hints and the automatic typing of commands to a terminal.
+
+### Frontend
+
+Note that our frontend implementation is written in Angular. It is maintained and documented in the `frontend-tutorial-framework` repository.
+
+### Messaging format
+
+The framework uses JSON messages internally and in exposed APIs as well.
+These messages must comply some rules.
+Don't worry, we are not too fond of rules around these parts.
+
+The TFW message format:
+
+```json
+{
+    "key: "some identifier used for addressing",
+    "data":
+    {
+        ...
+        JSON object carrying anything, preferably cats
+        ...
+    },
+    "trigger": "FSM action"
+}
+```
+
+- The `key` field is used by TFW for addressing and every message must have one (it can be an empty string though)
+- The `data` object can contain anything you might want to send
+- The `trigger` key is an optional field that triggers an FSM action with that name from the current state (whatever that might be)
+
+
+## Where to go next
+
+Most of the components you need have docstrings included (hang on tight, this is work in progress) – refer to them for usage info.
+
+To get started you should take a look at the `test-tutorial-framework` repository, which serves as an example project as well.

bashrc

@@ -0,0 +1,20 @@
+_postcmd() 
+{
+    AT_PROMPT=1
+    history -a
+}
+PROMPT_COMMAND="_postcmd"
+
+_precmd()
+{
+    [ -z "$AT_PROMPT" ] && return
+    unset AT_PROMPT
+    history -a
+}
+trap _precmd DEBUG
+
+shopt -s cmdhist
+shopt -s histappend
+unset HISTCONTROL
+export HISTFILESIZE=1000
+export HISTSIZE=1000

lib/envvars.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from collections import namedtuple
 from os import environ
 

lib/tao/__init__.py

@@ -0,0 +1,2 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.

lib/tao/config/__init__.py

@@ -1 +1,4 @@
-from .envvars import * # pylint: disable=wildcard-import
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .envvars import TAOENV

lib/tao/config/envvars.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from envvars import prefixed_envvars_to_namedtuple
 
 TAOENV = prefixed_envvars_to_namedtuple('AVATAO_', 'taoenvtuple')

lib/tfw/__init__.py

@@ -0,0 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .event_handler_base import EventHandlerBase, TriggeredEventHandler
+from .fsm_base import FSMBase
+from .linear_fsm import LinearFSM

lib/tfw/components/__init__.py

@@ -0,0 +1,9 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .directory_monitoring_event_handler import DirectoryMonitoringEventHandler
+from .process_managing_event_handler import ProcessManagingEventHandler
+from .terminado_event_handler import TerminadoEventHandler
+from .webide_event_handler import WebideEventHandler
+from .history_monitor import HistoryMonitor, BashMonitor, GDBMonitor
+from .terminal_commands import TerminalCommands

lib/tfw/components/decorators/__init__.py

@@ -1 +0,0 @@
-from .rate_limiter import RateLimiter

lib/tfw/components/directory_monitor.py

@@ -1,30 +1,26 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from functools import wraps
 
-from watchdog.observers import Observer
 from watchdog.events import FileSystemEventHandler as FileSystemWatchdogEventHandler
 
-from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
+from tfw.networking.event_handlers import ServerUplinkConnector
-from tfw.components.decorators import RateLimiter
+from tfw.decorators import RateLimiter
+from tfw.mixins import ObserverMixin
 
 from tfw.config.logs import logging
 
 LOG = logging.getLogger(__name__)
 
 
-class DirectoryMonitor:
+class DirectoryMonitor(ObserverMixin):
     def __init__(self, directory):
-        self.observer = Observer()
+        ObserverMixin.__init__(self)
         self.eventhandler = WebideReloadWatchdogEventHandler()
         self.observer.schedule(self.eventhandler, directory, recursive=True)
         self.pause, self.resume = self.eventhandler.pause, self.eventhandler.resume
 
-    def watch(self):
-        self.observer.start()
-
-    def stop(self):
-        self.observer.stop()
-        self.observer.join()
-
     @property
     def ignore(self):
         return self.eventhandler.ignore
@@ -67,8 +63,8 @@ class WebideReloadWatchdogEventHandler(FileSystemWatchdogEventHandler):
             self.ignore = self.ignore - 1
             return
         LOG.debug(event)
-        key = 'webide'
+        self.uplink.send({'key': 'webide',
-        self.uplink.send(key, {'data': {'command': 'reload'}})
+                          'data': {'command': 'reload'}})
 
 
 def with_monitor_paused(fun):

lib/tfw/components/directory_monitoring_event_handler.py

@@ -1,18 +1,22 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from os.path import isdir, exists
 
-from tfw.components.directory_monitor import DirectoryMonitor
+from tfw import EventHandlerBase
-from tfw.event_handler_base import TriggerlessEventHandler
 from tfw.config.logs import logging
+from tfw.mixins import MonitorManagerMixin
+from .directory_monitor import DirectoryMonitor
 
 LOG = logging.getLogger(__name__)
 
 
-class DirectoryMonitoringEventHandler(TriggerlessEventHandler):
+class DirectoryMonitoringEventHandler(EventHandlerBase, MonitorManagerMixin):
     def __init__(self, key, directory):
         super().__init__(key)
         self._directory = directory
-        self._monitor = None
+        MonitorManagerMixin.__init__(self, DirectoryMonitor, self._directory)
-        self.reload_monitor()
+
         self.commands = {'pause':     self.pause,
                          'resume':    self.resume,
                          'ignore':    self.ignore,
@@ -28,20 +32,7 @@ class DirectoryMonitoringEventHandler(TriggerlessEventHandler):
             raise EnvironmentError('No such directory!')
         self._directory = directory
 
-    @property
+    def handle_event(self, message):
-    def monitor(self):
-        return self._monitor
-
-    def reload_monitor(self):
-        if self._monitor:
-            try:
-                self._monitor.stop()
-            except KeyError:
-                logging.debug('Working directory was removed – ignoring...')
-        self._monitor = DirectoryMonitor(self._directory)
-        self._monitor.watch()   # This runs on a separate thread
-
-    def handle_event(self, key, message):
         try:
             message['data'] = self.commands[message['data']['command']](message['data'])
             return message

lib/tfw/components/history_monitor.py

@@ -1,13 +1,15 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from os.path import dirname
 from re import findall
 from re import compile as compileregex
 from abc import ABC, abstractmethod
 
-from watchdog.observers import Observer
 from watchdog.events import PatternMatchingEventHandler
 
-from tfw.components.mixins.callback_mixin import CallbackMixin
+from tfw.mixins import CallbackMixin, ObserverMixin
-from tfw.components.decorators.rate_limiter import RateLimiter
+from tfw.decorators import RateLimiter
 
 
 class CallbackEventHandler(PatternMatchingEventHandler, ABC):
@@ -21,13 +23,24 @@ class CallbackEventHandler(PatternMatchingEventHandler, ABC):
             callback()
 
 
-class HistoryMonitor(CallbackMixin, ABC):
+class HistoryMonitor(CallbackMixin, ObserverMixin, ABC):
+    """
+    Abstract class capable of monitoring and parsing a history file such as
+    bash HISTFILEs. Monitoring means detecting when the file was changed and
+    notifying subscribers about new content in the file.
+
+    This is useful for monitoring CLI sessions.
+
+    To specify a custom HistoryMonitor inherit from this class and override the
+    command pattern property and optionally the sanitize_command method.
+    See examples below.
+    """
     def __init__(self, histfile):
         CallbackMixin.__init__(self)
+        ObserverMixin.__init__(self)
         self.histfile = histfile
         self._history = []
         self._last_length = len(self._history)
-        self.observer = Observer()
         self.observer.schedule(CallbackEventHandler([self.histfile],
                                                     self._fetch_history,
                                                     self._invoke_callbacks),
@@ -57,15 +70,17 @@ class HistoryMonitor(CallbackMixin, ABC):
         if self._last_length < len(self._history):
             self._execute_callbacks(self.history)
 
-    def watch(self):
-        self.observer.start()
-
-    def stop(self):
-        self.observer.stop()
-        self.observer.join()
-
 
 class BashMonitor(HistoryMonitor):
+    """
+    HistoryMonitor for monitoring bash CLI sessions.
+    This requires the following to be set in bash
+    (note that this is done automatically by TFW):
+        PROMPT_COMMAND="history -a"
+        shopt -s cmdhist
+        shopt -s histappend
+        unset HISTCONTROL
+    """
     @property
     def command_pattern(self):
         return r'.+'
@@ -75,6 +90,10 @@ class BashMonitor(HistoryMonitor):
 
 
 class GDBMonitor(HistoryMonitor):
+    """
+    HistoryMonitor to monitor GDB sessions.
+    For this to work "set trace-commands on" must be set in GDB.
+    """
     @property
     def command_pattern(self):
         return r'(?<=\n)\+(.+)\n'

lib/tfw/components/mixins/__init__.py

@@ -1 +0,0 @@
-from .supervisor_mixin import SupervisorMixin

lib/tfw/components/process_managing_event_handler.py

@@ -1,9 +1,12 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from xmlrpc.client import Fault as SupervisorFault
 
-from tfw.event_handler_base import TriggerlessEventHandler
+from tfw import EventHandlerBase
-from tfw.components.mixins import SupervisorMixin
+from tfw.mixins import SupervisorMixin
-from tfw.components.directory_monitor import with_monitor_paused
 from tfw.config.logs import logging
+from .directory_monitor import with_monitor_paused
 
 LOG = logging.getLogger(__name__)
 
@@ -19,7 +22,19 @@ class ProcessManager(SupervisorMixin):
         return self.commands[command](process_name)
 
 
-class ProcessManagingEventHandler(TriggerlessEventHandler):
+class ProcessManagingEventHandler(EventHandlerBase):
+    """
+    Event handler that can manage processes managed by supervisor.
+
+    This EventHandler accepts messages that have a data["command"] key specifying
+    a command to be executed.
+    Every message must contain a data["process_name"] field with the name of the
+    process to manage. This is the name specified in supervisor config files like so:
+    [program:someprogram]
+
+    Commands available: start, stop, restart, readlog
+    (the names are as self-documenting as it gets)
+    """
     def __init__(self, key, dirmonitor=None):
         super().__init__(key)
         self.key = key
@@ -27,7 +42,7 @@ class ProcessManagingEventHandler(TriggerlessEventHandler):
         self.processmanager = ProcessManager()
 
     @with_monitor_paused
-    def handle_event(self, key, message):
+    def handle_event(self, message):
         try:
             data = message['data']
             self.processmanager(data['command'], data['process_name'])

lib/tfw/components/terminado_event_handler.py

@@ -1,17 +1,35 @@
-from tfw.components.terminado_mini_server import TerminadoMiniServer
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
-from tfw.event_handler_base import TriggerlessEventHandler
+# All Rights Reserved. See LICENSE file for details.
+
+from tfw import EventHandlerBase
 from tfw.config import TFWENV
 from tfw.config.logs import logging
+from tao.config import TAOENV
+from .terminado_mini_server import TerminadoMiniServer
 
 LOG = logging.getLogger(__name__)
 
 
-class TerminadoEventHandler(TriggerlessEventHandler):
+class TerminadoEventHandler(EventHandlerBase):
+    """
+    Event handler responsible for managing terminal sessions for frontend xterm
+    sessions to connect to. You need to instanciate this in order for frontend
+    terminals to work.
+
+    This EventHandler accepts messages that have a data["command"] key specifying
+    a command to be executed.
+    The API of each command is documented in their respective handlers.
+    """
     def __init__(self, key, monitor):
+        """
+        :param key: key this EventHandler listens to
+        :param monitor: tfw.components.HistoryMonitor instance to read command history from
+        """
         super().__init__(key)
         self.working_directory = TFWENV.TERMINADO_DIR
         self._historymonitor = monitor
-        self.terminado_server = TerminadoMiniServer('/terminal', TFWENV.TERMINADO_PORT, TFWENV.TERMINADO_WD, ['bash'])
+        bash_as_user_cmd = ['sudo', '-u', TAOENV.USER, 'bash']
+        self.terminado_server = TerminadoMiniServer('/terminal', TFWENV.TERMINADO_PORT, TFWENV.TERMINADO_WD, bash_as_user_cmd)
         self.commands = {'write': self.write,
                          'read': self.read}
         if self._historymonitor:
@@ -22,18 +40,31 @@ class TerminadoEventHandler(TriggerlessEventHandler):
     def historymonitor(self):
         return self._historymonitor
 
-    def handle_event(self, key, message):
+    def handle_event(self, message):
         LOG.debug('TerminadoEventHandler received event: %s', message)
         try:
-            message['data'] = self.commands[message['data']['command']](message['data'])
+            data = message['data']
+            message['data'] = self.commands[data['command']](data)
             return message
         except KeyError:
             LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)
 
     def write(self, data):
+        """
+        Writes a string to the terminal session (on the pty level).
+        Useful for pre-typing and executing commands for the user.
+
+        :param data['shellcmd']: command to be written to the pty
+        """
         self.terminado_server.pty.write(data['shellcmd'])
 
     def read(self, data):
+        """
+        Reads the history of commands executed.
+
+        :param data['count']: the number of history elements to return
+        :return: message with list of commands in data['history']
+        """
         data['count'] = int(data.get('count', 1))
         if self.historymonitor:
             data['history'] = self.historymonitor.history[-data['count']:]

lib/tfw/components/terminado_mini_server.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from tornado.ioloop import IOLoop
 from tornado.web import Application
 from terminado import TermSocket, SingleTermManager

lib/tfw/components/terminal_commands.py

@@ -0,0 +1,66 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from abc import ABC
+from re import match
+
+from tfw.config.logs import logging
+
+LOG = logging.getLogger(__name__)
+
+
+class TerminalCommands(ABC):
+    """
+    A class you can use to define hooks for terminal commands. This means that you can
+    have python code executed when the user enters a specific command to the terminal on
+    our frontend.
+
+    To receive events you need to subscribe TerminalCommand.callback to a HistoryMonitor
+    instance.
+
+    Inherit from this class and define methods which start with "command_". When the user
+    executes the command specified after the underscore, your method will be invoked. All
+    such commands must expect the parameter *args which will contain the arguments of the
+    command.
+
+    For example to define a method that runs when someone starts vim in the terminal
+    you have to define a method like: "def command_vim(self, *args)"
+
+    You can also use this class to create new commands similarly.
+    """
+    def __init__(self, bashrc=None):
+        self._command_method_regex = r'^command_(.+)$'
+        self.command_implemetations = self._build_command_to_implementation_dict()
+        if bashrc is not None:
+            self._setup_bashrc_aliases(bashrc)
+
+    def _build_command_to_implementation_dict(self):
+        return {self._parse_command_name(fun): getattr(self, fun) for fun in dir(self)
+                if callable(getattr(self, fun)) and self._is_command_implementation(fun)}
+
+    def _setup_bashrc_aliases(self, bashrc):
+        with open(bashrc, 'a') as ofile:
+            alias_template = 'type {0} &> /dev/null || alias {0}="{0} &> /dev/null"\n'
+            for command in self.command_implemetations.keys():
+                ofile.write(alias_template.format(command))
+
+    def _is_command_implementation(self, method_name):
+        return bool(self._match_command_regex(method_name))
+
+    def _parse_command_name(self, method_name):
+        try:
+            return self._match_command_regex(method_name).groups()[0]
+        except AttributeError:
+            return ''
+
+    def _match_command_regex(self, string):
+        return match(self._command_method_regex, string)
+
+    def callback(self, history):
+        parts = history[-1].split()
+        command = parts[0]
+        if command in self.command_implemetations.keys():
+            try:
+                self.command_implemetations[command](*parts[1:])
+            except IndexError:
+                LOG.debug('Command "%s" failed!', command)

lib/tfw/components/webide_event_handler.py

@@ -1,18 +1,23 @@
-from os.path import isfile, join, relpath, exists, isdir
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from os.path import isfile, join, relpath, exists, isdir, realpath
 from glob import glob
 from fnmatch import fnmatchcase
 from collections import Iterable
 
-from tfw.event_handler_base import TriggerlessEventHandler
+from tfw import EventHandlerBase
-from tfw.components.directory_monitor import DirectoryMonitor
+from tfw.mixins import MonitorManagerMixin
 from tfw.config.logs import logging
+from .directory_monitor import DirectoryMonitor
 
 LOG = logging.getLogger(__name__)
 
 
-class FileManager:
+class FileManager:  # pylint: disable=too-many-instance-attributes
-    def __init__(self, working_directory, selected_file=None, exclude=None):
+    def __init__(self, working_directory, allowed_directories, selected_file=None, exclude=None):
         self._exclude, self.exclude = None, exclude
+        self._allowed_directories, self.allowed_directories = None, allowed_directories
         self._workdir, self.workdir = None, working_directory
         self._filename, self.filename = None, selected_file or self.files[0]
 
@@ -36,23 +41,32 @@ class FileManager:
     def workdir(self, directory):
         if not exists(directory) or not isdir(directory):
             raise EnvironmentError('"{}" is not a directory!'.format(directory))
+        if not self._is_in_whitelisted_dir(directory):
+            raise EnvironmentError('Directory "{}" is not in whitelist!'.format(directory))
         self._workdir = directory
 
+    @property
+    def allowed_directories(self):
+        return self._allowed_directories
+
+    @allowed_directories.setter
+    def allowed_directories(self, directories):
+        self._allowed_directories = directories
+
     @property
     def filename(self):
         return self._filename
 
     @filename.setter
     def filename(self, filename):
-        if not filename in self.files:
+        if filename not in self.files:
             raise EnvironmentError('No such file in workdir!')
         self._filename = filename
 
     @property
     def files(self):
         return [self._relpath(file) for file in glob(join(self._workdir, '**/*'), recursive=True)
-                if isfile(file) and
+                if isfile(file) and self._is_in_whitelisted_dir(file) and not self._is_blacklisted(file)]
-                not any(fnmatchcase(file, blacklisted) for blacklisted in self.exclude)]
 
     @property
     def file_contents(self):
@@ -64,6 +78,12 @@ class FileManager:
         with open(self._filepath(self.filename), 'w', errors='surrogateescape') as ofile:
             ofile.write(value)
 
+    def _is_in_whitelisted_dir(self, path):
+        return any(realpath(path).startswith(allowed_dir) for allowed_dir in self.allowed_directories)
+
+    def _is_blacklisted(self, file):
+        return any(fnmatchcase(file, blacklisted) for blacklisted in self.exclude)
+
     def _filepath(self, filename):
         return join(self._workdir, filename)
 
@@ -71,10 +91,29 @@ class FileManager:
         return relpath(self._filepath(filename), start=self._workdir)
 
 
-class SourceCodeEventHandler(TriggerlessEventHandler):
+class WebideEventHandler(EventHandlerBase, MonitorManagerMixin):
-    def __init__(self, key, directory, selected_file=None, exclude=None):
+    # pylint: disable=too-many-arguments
+    """
+    Event handler implementing the backend of our browser based IDE.
+    By default all files in the directory specified in __init__ are displayed
+    on the fontend. Note that this is a stateful component.
+
+    This EventHandler accepts messages that have a data["command"] key specifying
+    a command to be executed.
+    The API of each command is documented in their respective handlers.
+    """
+    def __init__(self, key, directory, allowed_directories, selected_file=None, exclude=None):
+        """
+        :param key: the key this instance should listen to
+        :param directory: working directory which the EventHandler should serve files from
+        :param allowed_directories: list of directories that can be switched to using the selectdir command
+        :param selected_file: file that is selected by default
+        :param exclude: list of filenames that should not appear between files (for *.o, *.pyc, etc.)
+        """
         super().__init__(key)
-        self.filemanager = FileManager(directory, selected_file=selected_file, exclude=exclude)
+        self.filemanager = FileManager(allowed_directories=allowed_directories, working_directory=directory,
+                                       selected_file=selected_file, exclude=exclude)
+        MonitorManagerMixin.__init__(self, DirectoryMonitor, self.filemanager.workdir)
 
         self.commands = {'read':      self.read,
                          'write':     self.write,
@@ -82,23 +121,12 @@ class SourceCodeEventHandler(TriggerlessEventHandler):
                          'selectdir': self.select_dir,
                          'exclude':   self.exclude}
 
-        self._monitor = None
-        self.reload_monitor()
-
-    @property
-    def monitor(self):
-        return self._monitor
-
-    def reload_monitor(self):
-        if self._monitor:
-            try:
-                self._monitor.stop()
-            except KeyError:
-                logging.debug('Working directory was removed – ignoring...')
-        self._monitor = DirectoryMonitor(self.filemanager.workdir)
-        self._monitor.watch()   # This runs on a separate thread
-
     def read(self, data):
+        """
+        Read the currently selected file.
+
+        :return: message with the contents of the file in data['content']
+        """
         try:
             data['content'] = self.filemanager.file_contents
         except PermissionError:
@@ -110,6 +138,11 @@ class SourceCodeEventHandler(TriggerlessEventHandler):
         return data
 
     def write(self, data):
+        """
+        Overwrites a file with the desired string.
+
+        :param data['content']: string containing the desired file contents
+        """
         self.monitor.ignore = self.monitor.ignore + 1
         try:
             self.filemanager.file_contents = data['content']
@@ -119,6 +152,11 @@ class SourceCodeEventHandler(TriggerlessEventHandler):
         return data
 
     def select(self, data):
+        """
+        Selects a file from the current directory.
+
+        :param data['filename']: name of file to select relative to the current directory
+        """
         try:
             self.filemanager.filename = data['filename']
         except EnvironmentError:
@@ -126,6 +164,13 @@ class SourceCodeEventHandler(TriggerlessEventHandler):
         return data
 
     def select_dir(self, data):
+        """
+        Select a new working directory to display files from.
+
+        :param data['directory']: absolute path of diretory to select.
+                                  must be a path whitelisted in
+                                  self.allowed_directories
+        """
         try:
             self.filemanager.workdir = data['directory']
             self.reload_monitor()
@@ -134,11 +179,16 @@ class SourceCodeEventHandler(TriggerlessEventHandler):
                 self.read(data)
             except IndexError:
                 data['content'] = 'No files in this directory :('
-        except EnvironmentError:
+        except EnvironmentError as err:
-            LOG.error('Failed to select directory "%s"', data['directory'])
+            LOG.error('Failed to select directory "%s". Reason: %s', data['directory'], str(err))
         return data
 
     def exclude(self, data):
+        """
+        Overwrite list of excluded files
+
+        :param data['exclude']: list of filename patterns to be excluded, e.g.: ["*.pyc", "*.o"]
+        """
         try:
             self.filemanager.exclude = list(data['exclude'])
         except TypeError:
@@ -146,11 +196,14 @@ class SourceCodeEventHandler(TriggerlessEventHandler):
         return data
 
     def attach_fileinfo(self, data):
+        """
+        Basic information included in every response to the frontend.
+        """
         data['filename'] = self.filemanager.filename
         data['files'] = self.filemanager.files
         data['directory'] = self.filemanager.workdir
 
-    def handle_event(self, key, message):
+    def handle_event(self, message):
         try:
             data = message['data']
             message['data'] = self.commands[data['command']](data)

lib/tfw/config/__init__.py

@@ -1 +1,4 @@
-from .envvars import *
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .envvars import TFWENV

lib/tfw/config/envvars.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from envvars import prefixed_envvars_to_namedtuple
 
 TFWENV = prefixed_envvars_to_namedtuple('TFW_', 'tfwenvtuple')

lib/tfw/config/logs.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 import logging
 
 logging.basicConfig(level=logging.DEBUG)

lib/tfw/decorators/__init__.py

@@ -0,0 +1,4 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .rate_limiter import RateLimiter

lib/tfw/decorators/rate_limiter.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from functools import wraps
 from time import time, sleep
 

lib/tfw/event_handler_base.py

@@ -1,85 +1,104 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from abc import ABC, abstractmethod
 
-from tfw.networking.serialization import deserialize_all
+from tfw.networking import deserialize_tfw_msg
-from tfw.networking.event_handlers.server_connector import ServerConnector
+from tfw.networking.event_handlers import ServerConnector
 
 
 class EventHandlerBase(ABC):
+    """
+    Abstract base class for all Python based EventHandlers. Useful implementation template
+    for other languages.
+
+    Derived classes must implement the handle_event() method
+    """
     def __init__(self, key):
         self.server_connector = ServerConnector()
         self.key = key
-        self.subscriptions = set()
+        self.subscribe(self.key, 'reset')
-        self.subscribe(self.key)
-        self.subscribe('reset')
         self.server_connector.register_callback(self.event_handler_callback)
 
     def event_handler_callback(self, msg_parts):
-        key, message = deserialize_all(*msg_parts)
+        """
-        response = self.dispatch_handling(key, message)
+        Callback that is invoked when receiving a message.
-        if response is None:
+        Dispatches messages to handler methods and sends
-            return
+        a response back in case the handler returned something.
-        self.server_connector.send(key, response)
+        This is subscribed in __init__().
+        """
+        message = deserialize_tfw_msg(*msg_parts)
+        response = self.dispatch_handling(message)
+        if response:
+            response['key'] = message['key']
+            self.server_connector.send(response)
+
+    def dispatch_handling(self, message):
+        """
+        Used to dispatch messages to their specific handlers.
+        """
+        if message['key'] != 'reset':
+            return self.handle_event(message)
+        return self.handle_reset(message)
 
     @abstractmethod
-    def dispatch_handling(self, key, message):
+    def handle_event(self, message):
-        raise NotImplementedError
+        """
+        Abstract method that implements the handling of messages.
 
-    def _dispatch_handling(self, key, message):
+        :param message: the message received
-        # pylint: disable=no-else-return
+        """
-        if key != 'reset':
-            return self.handle_event(key, message)
-        else:
-            return self.handle_reset(message)
-
-    @abstractmethod
-    def handle_event(self, key, message):
         raise NotImplementedError
 
     def handle_reset(self, message):
         # pylint: disable=unused-argument,no-self-use
+        """
+        Usually 'reset' events receive some sort of special treatment.
+
+        :param message: the message received
+        """
         return None
 
-    def cleanup(self):
+    def subscribe(self, *keys):
-        pass
+        """
-
+        Subscribe this EventHandler to receive events for given keys.
-    def message_other(self, key, data):
+        Note that you can subscribe to the same key several times in which
-        message = {
+        case you will need to unsubscribe multiple times in order to stop
-            'key': key,
+        receiving events.
-            'data': data
+        
-        }
+        :param keys: list of keys to subscribe to
-        self.server_connector.send(key, message)
+        """
-
+        for key in keys:
-    def subscribe(self, key):
-        if key not in self.subscriptions:
-            self.subscriptions.add(key)
             self.server_connector.subscribe(key)
 
-    def unsubscribe(self, key):
+    def unsubscribe(self, *keys):
-        try:
+        """
-            self.subscriptions.remove(key)
+        Unsubscribe this eventhandler from the given keys.
+
+        :param keys: list of keys to unsubscribe from
+        """
+        for key in keys:
             self.server_connector.unsubscribe(key)
-        except KeyError:
-            pass
 
-    def unsubscribe_all(self):
+    def cleanup(self):
-        for sub in self.subscriptions:
+        """
-            self.server_connector.unsubscribe(key=sub)
+        Perform cleanup actions such as releasing database
-        self.subscriptions.clear()
+        connections and stuff like that.
-
+        """
-
+        pass
-class TriggerlessEventHandler(EventHandlerBase, ABC):
-    # pylint: disable=abstract-method
-    def dispatch_handling(self, key, message):
-        return self._dispatch_handling(key, message)
 
 
 class TriggeredEventHandler(EventHandlerBase, ABC):
     # pylint: disable=abstract-method
+    """
+    Abstract base class for EventHandlers which are only triggered in case
+    TFWServer has successfully triggered an FSM step defined in __init__.
+    """
     def __init__(self, key, trigger):
         super().__init__(key)
         self.trigger = trigger
 
-    def dispatch_handling(self, key, message):
+    def dispatch_handling(self, message):
         if message.get('trigger') == self.trigger:
-            return self._dispatch_handling(key, message)
+            return super().dispatch_handling(message)
         return None

lib/tfw/fsm_base.py

@@ -1,11 +1,21 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from typing import List
 
 from transitions import Machine
 
-from tfw.components.mixins.callback_mixin import CallbackMixin
+from tfw.mixins import CallbackMixin
 
 
 class FSMBase(CallbackMixin):
+    """
+    A general FSM base class you can inherit from to track user progress.
+    See linear_fsm.py for an example use-case.
+    TFW the transitions library for state machines, please refer to their
+    documentation for more information on creating your own machines:
+    https://github.com/pytransitions/transitions
+    """
     states, transitions = [], []
 
     def __init__(self, initial: str = None, accepted_states: List[str] = None):

lib/tfw/linear_fsm.py

@@ -0,0 +1,18 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .fsm_base import FSMBase
+
+
+class LinearFSM(FSMBase):
+    """
+    This is a state machine for challenges with linear progression, consisting of
+    a number of steps specified in the constructor. It automatically sets up a single
+    action between states as such:
+    0 ==step_1==> 1 ==step_2==> 2 ==step_3==> 3 ... and so on
+    """
+    def __init__(self, number_of_steps):
+        self.states = list(map(str, range(number_of_steps)))
+        self.transitions = [{'trigger': 'step_{}'.format(int(index)+1), 'source': index, 'dest': str(int(index)+1)}
+                            for index in self.states[:-1]]
+        super(LinearFSM, self).__init__()

lib/tfw/message_sender.py

@@ -1,18 +0,0 @@
-from datetime import datetime
-
-from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
-
-
-class MessageSender:
-    def __init__(self, custom_key: str = None):
-        self.server_connector = ServerUplinkConnector()
-        self.key = custom_key or 'message'
-
-    def send(self, originator, message):
-        data = {
-            'originator': originator,
-            'timestamp': datetime.now().isoformat(),
-            'message': message
-        }
-        response = {'data': data}
-        self.server_connector.send(self.key, response)

lib/tfw/mixins/__init__.py

@@ -0,0 +1,7 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .supervisor_mixin import SupervisorMixin
+from .callback_mixin import CallbackMixin
+from .observer_mixin import ObserverMixin
+from .monitor_manager_mixin import MonitorManagerMixin

lib/tfw/mixins/callback_mixin.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from functools import partial
 
 
@@ -6,6 +9,12 @@ class CallbackMixin:
         self._callbacks = []
 
     def subscribe_callback(self, callback, *args, **kwargs):
+        """
+        Subscribe a callable to invoke once an event is triggered.
+        :param callback: callable to be executed on events
+        :param *args: arguments passed to callable
+        :param **kwargs: kwargs passed to callable
+        """
         fun = partial(callback, *args, **kwargs)
         self._callbacks.append(fun)
 

lib/tfw/mixins/monitor_manager_mixin.py

@@ -0,0 +1,27 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from tfw.config.logs import logging
+
+LOG = logging.getLogger(__name__)
+
+
+class MonitorManagerMixin:
+    def __init__(self, monitor_type, directory):
+        self._monitor_type = monitor_type
+        self._monitor = None
+        self._monitored_directory = directory
+        self.reload_monitor()
+
+    @property
+    def monitor(self):
+        return self._monitor
+
+    def reload_monitor(self):
+        if self._monitor:
+            try:
+                self._monitor.stop()
+            except KeyError:
+                LOG.debug('Working directory was removed – ignoring...')
+        self._monitor = self._monitor_type(self._monitored_directory)
+        self._monitor.watch()   # This runs on a separate thread

lib/tfw/mixins/observer_mixin.py

@@ -0,0 +1,16 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from watchdog.observers import Observer
+
+
+class ObserverMixin:
+    def __init__(self):
+        self.observer = Observer()
+
+    def watch(self):
+        self.observer.start()
+
+    def stop(self):
+        self.observer.stop()
+        self.observer.join()

lib/tfw/mixins/supervisor_mixin.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 import xmlrpc.client
 from xmlrpc.client import Fault as SupervisorFault
 from contextlib import suppress

lib/tfw/networking/__init__.py

@@ -0,0 +1,9 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .serialization import serialize_tfw_msg, deserialize_tfw_msg, validate_message
+from .zmq_connector_base import ZMQConnectorBase
+# from .controller_connector import ControllerConnector # TODO: readd once controller stuff is resolved
+from .message_sender import MessageSender
+from .event_handlers.server_connector import ServerUplinkConnector as TFWServerConnector
+from .server.tfw_server import TFWServer

lib/tfw/networking/controller_connector.py

@@ -1,8 +1,11 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 import zmq
 from zmq.eventloop.zmqstream import ZMQStream
 
 from tfw.config import TFWENV
-from tfw.networking.zmq_connector_base import ZMQConnectorBase
+from tfw.networking import ZMQConnectorBase
 
 
 class ControllerConnector(ZMQConnectorBase):

lib/tfw/networking/event_handlers/__init__.py

@@ -0,0 +1,4 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .server_connector import ServerConnector, ServerUplinkConnector, ServerDownlinkConnector

lib/tfw/networking/event_handlers/server_connector.py

@@ -1,11 +1,14 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from functools import partial
 
 import zmq
 from zmq.eventloop.zmqstream import ZMQStream
 
-from tfw.networking.serialization import serialize_all
+from tfw.networking import serialize_tfw_msg
+from tfw.networking import ZMQConnectorBase
 from tfw.config import TFWENV
-from tfw.networking.zmq_connector_base import ZMQConnectorBase
 
 
 class ServerDownlinkConnector(ZMQConnectorBase):
@@ -21,18 +24,31 @@ class ServerDownlinkConnector(ZMQConnectorBase):
 
 
 class ServerUplinkConnector(ZMQConnectorBase):
+    """
+    Class capable of sending messages to the TFW server and event handlers.
+    """
     def __init__(self, zmq_context=None):
         super(ServerUplinkConnector, self).__init__(zmq_context)
         self._zmq_push_socket = self._zmq_context.socket(zmq.PUSH)
         self._zmq_push_socket.connect('tcp://localhost:{}'.format(TFWENV.RECEIVER_PORT))
 
-    def send_to_eventhandler(self, key, message):
+    def send_to_eventhandler(self, message):
-        message['data']['key'] = key
+        """
-        self.send('mirror', message)
+        Send a message to an event handler.
+        :param message: JSON message you want to send
+        :param message['key']: key of event handler you want to address
+        """
+        nested_message = {'key': message['key'], 'data': message.pop('data')}
+        message['key'] = 'mirror'
+        message['data'] = nested_message
+        self.send(message)
 
-    def send(self, key, message):
+    def send(self, message):
-        message['key'] = key
+        """
-        self._zmq_push_socket.send_multipart(serialize_all(key, message))
+        Send a message to the TFW server
+        :param message: JSON message you want to send
+        """
+        self._zmq_push_socket.send_multipart(serialize_tfw_msg(message))
 
 
 class ServerConnector(ServerUplinkConnector, ServerDownlinkConnector):

lib/tfw/networking/message_sender.py

@@ -0,0 +1,30 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from datetime import datetime
+
+from tfw.networking.event_handlers import ServerUplinkConnector
+
+
+class MessageSender:
+    """
+    Provides a mechanism to send messages to our frontend messaging component which
+    displays messages with the key "message".
+    """
+    def __init__(self, custom_key: str = None):
+        self.server_connector = ServerUplinkConnector()
+        self.key = custom_key or 'message'
+
+    def send(self, originator, message):
+        """
+        Sends a message to the key specified in __init__.
+        :param originator: name of sender to be displayed on the frontend
+        :param message: message to send
+        """
+        data = {
+            'originator': originator,
+            'timestamp': datetime.now().isoformat(),
+            'message': message
+        }
+        self.server_connector.send({'key': self.key,
+                                    'data': data})

lib/tfw/networking/serialization.py

@@ -1,21 +1,69 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+"""
+TFW JSON message format
+
+message:
+{
+    "key":     string,    # addressing
+    "data":    {...},     # payload
+    "trigger": string     # FSM trigger
+}
+
+ZeroMQ's sub-pub sockets use enveloped messages
+(http://zguide.zeromq.org/page:all#Pub-Sub-Message-Envelopes)
+and TFW also uses them internally. This means that on ZMQ sockets
+we always send the messages key separately and then the actual
+message (which contains the key as well) like so:
+
+socket.send_multipart([message['key'], message])
+
+The purpose of this module is abstracting away this low level behaviour.
+"""
+
 import json
 
 
-def encode_if_needed(value):
+def validate_message(message):
+    return 'key' in message
+
+
+def serialize_tfw_msg(message):
+    return _serialize_all(message['key'], message)
+
+
+def deserialize_tfw_msg(*args):
+    return _deserialize_all(*args)[1]
+
+
+def _serialize_all(*args):
+    return tuple(_serialize_single(arg) for arg in args)
+
+
+def _deserialize_all(*args):
+    return tuple(_deserialize_single(arg) for arg in args)
+
+
+def _serialize_single(data):
+    if not isinstance(data, str):
+        data = json.dumps(data)
+    return _encode_if_needed(data)
+
+
+def _deserialize_single(data):
+    try:
+        return json.loads(data)
+    except ValueError:
+        return _decode_if_needed(data)
+
+
+def _encode_if_needed(value):
     if isinstance(value, str):
         value = value.encode('utf-8')
     return value
 
 
-def decode_if_needed(value):
+def _decode_if_needed(value):
     if isinstance(value, (bytes, bytearray)):
         value = value.decode('utf-8')
     return value
-
-
-def serialize_all(key, data):
-    return [encode_if_needed(frame) for frame in (key, json.dumps(data))]
-
-
-def deserialize_all(key, data):
-    return decode_if_needed(key), json.loads(data)

lib/tfw/networking/server/__init__.py

@@ -0,0 +1,7 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from .event_handler_connector import EventHandlerConnector, EventHandlerUplinkConnector, EventHandlerDownlinkConnector
+from .tfw_server import TFWServer
+from .zmq_websocket_handler import ZMQWebSocketProxy
+# from .controller_responder import ControllerResponder  # TODO: readd once controller stuff is resolved

lib/tfw/networking/server/controller_responder.py

@@ -1,5 +1,7 @@
-from tfw.networking.controller_connector import ControllerConnector
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
-from tfw.networking.serialization import deserialize_all, serialize_all
+# All Rights Reserved. See LICENSE file for details.
+
+from tfw.networking import deserialize_all, serialize_all, ControllerConnector
 
 
 class ControllerResponder:

lib/tfw/networking/server/event_handler_connector.py

@@ -1,8 +1,10 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 import zmq
 from zmq.eventloop.zmqstream import ZMQStream
 
-from tfw.networking.zmq_connector_base import ZMQConnectorBase
+from tfw.networking import ZMQConnectorBase, serialize_tfw_msg
-from tfw.networking.serialization import serialize_all
 from tfw.config import TFWENV
 from tfw.config.logs import logging
 
@@ -32,7 +34,5 @@ class EventHandlerConnector(EventHandlerDownlinkConnector, EventHandlerUplinkCon
     def register_callback(self, callback):
         self._zmq_pull_stream.on_recv(callback)
 
-    def send_message(self, message: dict, key: str = None):
+    def send_message(self, message: dict):
-        if not key:
+        self._zmq_pub_socket.send_multipart(serialize_tfw_msg(message))
-            key = message.get('key', '')
-        self._zmq_pub_socket.send_multipart(serialize_all(key, message))

lib/tfw/networking/server/tfw_server.py

@@ -1,25 +1,40 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 from collections import defaultdict
 
 from tornado.web import Application
 
-from tfw.networking.server.zmq_websocket_handler import ZMQWebSocketProxy
+from tfw.networking import MessageSender
-from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
+from tfw.networking.event_handlers import ServerUplinkConnector
-from tfw.message_sender import MessageSender
+from tfw.networking.server import EventHandlerConnector
 from tfw.config.logs import logging
+from .zmq_websocket_handler import ZMQWebSocketProxy
 
 LOG = logging.getLogger(__name__)
 
 
 class TFWServer:
+    """
+    This class handles the proxying of messages between the frontend and event handers.
+    It proxies messages from the "/ws" route to all event handlers subscribed to a ZMQ
+    SUB socket. It also manages an FSM you can define as a constructor argument.
+    """
     def __init__(self, fsm_type):
+        """
+        :param fsm_type: the type of FSM you want TFW to use
+        """
         self._fsm = fsm_type()
         self._fsm_updater = FSMUpdater(self._fsm)
         self._fsm_manager = FSMManager(self._fsm)
         self._fsm.subscribe_callback(self._fsm_updater.update)
+        self._event_handler_connector = EventHandlerConnector()
 
         self.application = Application(
-            [(r'/ws', ZMQWebSocketProxy, {'make_response': self.make_response,
+            [(r'/ws', ZMQWebSocketProxy, {'make_eventhandler_message': self.make_eventhandler_message,
-                                          'proxy_filter': self.proxy_filter})]
+                                          'proxy_filter': self.proxy_filter,
+                                          'handle_trigger': self.handle_trigger,
+                                          'event_handler_connector': self._event_handler_connector})]
         )
         #self.controller_responder = ControllerResponder(self.fsm) TODO: add this once controller stuff is resolved
 
@@ -31,13 +46,21 @@ class TFWServer:
     def fsm_manager(self):
         return self._fsm_manager
 
-    def make_response(self, message):
+    def make_eventhandler_message(self, message):
+        self.trigger_fsm(message)
+        message['FSMUpdate'] = self._fsm_updater.get_fsm_state_and_transitions()
+        return message
+
+    def handle_trigger(self, message):
+        LOG.debug('Executing handler for trigger "%s"', message.get('trigger', ''))
+        self.trigger_fsm(message)
+
+    def trigger_fsm(self, message):
         trigger = message.get('trigger', '')
         try:
             self._fsm_manager.trigger(trigger, message)
         except AttributeError:
             LOG.debug('FSM failed to execute nonexistent trigger: "%s"', trigger)
-        return message
 
     def proxy_filter(self, message):
         # pylint: disable=unused-argument,no-self-use
@@ -60,7 +83,7 @@ class FSMManager:
     def trigger(self, trigger, message):
         predicate_results = []
         for predicate in self.trigger_predicates[trigger]:
-            success, message = predicate()
+            success, message = predicate(message)
             predicate_results.append(success)
             self.messenge_sender.send('FSM', message)
 
@@ -85,11 +108,13 @@ class FSMUpdater:
 
     def update(self, kwargs_dict):
         # pylint: disable=unused-argument
-        self.uplink.send(*self.generate_fsm_update())
+        self.uplink.send(self.generate_fsm_update())
 
     def generate_fsm_update(self):
-        key = 'FSMUpdate'
+        return {'key': 'FSMUpdate',
-        response = {'data': {'current_state': self.fsm.state,
+                'data': self.get_fsm_state_and_transitions()}
-                             'valid_transitions':
+
-                                 [{'trigger': trigger} for trigger in self.fsm.machine.get_triggers(self.fsm.state)]}}
+    def get_fsm_state_and_transitions(self):
-        return key, response
+        state = self.fsm.state
+        valid_transitions = [{'trigger': trigger} for trigger in self.fsm.machine.get_triggers(self.fsm.state)]
+        return {'current_state': state, 'valid_transitions': valid_transitions}

lib/tfw/networking/server/zmq_websocket_handler.py

@@ -1,19 +1,23 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 import json
 from abc import ABC, abstractmethod
 
 from tornado.websocket import WebSocketHandler
 
-from tfw.networking.serialization import deserialize_all
+from tfw.networking import deserialize_tfw_msg, validate_message
-from tfw.networking.server.event_handler_connector import EventHandlerConnector
 from tfw.config.logs import logging
 
 LOG = logging.getLogger(__name__)
 
 
 class ZMQWebSocketHandler(WebSocketHandler, ABC):
-    _event_handler_connector = EventHandlerConnector()
     instances = set()
 
+    def initialize(self, **kwargs): # pylint: disable=arguments-differ
+        self._event_handler_connector = kwargs['event_handler_connector']
+
     def prepare(self):
         ZMQWebSocketHandler.instances.add(self)
 
@@ -24,36 +28,43 @@ class ZMQWebSocketHandler(WebSocketHandler, ABC):
         LOG.debug('WebSocket connection initiated')
         self._event_handler_connector.register_callback(self.zmq_callback)
 
-    @classmethod
+    def zmq_callback(self, msg_parts):
-    def zmq_callback(cls, msg_parts):
+        keyhandlers = {'mirror': self.mirror}
-        keyhandlers = {'mirror': cls.mirror}
 
-        key, data = deserialize_all(*msg_parts)
+        message = deserialize_tfw_msg(*msg_parts)
-        LOG.debug('Received on pull socket: %s', data)
+        LOG.debug('Received on pull socket: %s', message)
-        if key not in keyhandlers:
+        if not validate_message(message):
-            for instance in cls.instances:
+            return
-                instance.write_message(data)
+
+        self.handle_trigger(message)
+        if message['key'] not in keyhandlers:
+            for instance in ZMQWebSocketHandler.instances:
+                instance.write_message(message)
         else:
             try:
-                keyhandlers[key](data['data'])
+                keyhandlers[message['key']](message)
             except KeyError:
                 LOG.error('Invalid mirror message format! Ignoring.')
 
-    @classmethod
+    def mirror(self, message):
-    def mirror(cls, data):
+        message = message['data']
-        key = data['key']
+        self._event_handler_connector.send_message(message)
-        cls._event_handler_connector.send_message({'data': data}, key)
 
     def on_message(self, message):
         LOG.debug('Received on WebSocket: %s', message)
-        self.send_message(self.make_response(message))
+        if validate_message(message):
+            self.send_message(self.make_eventhandler_message(message))
 
     @abstractmethod
-    def make_response(self, message):
+    def make_eventhandler_message(self, message):
         raise NotImplementedError
 
-    def send_message(self, message: dict, key: str = None):
+    def send_message(self, message: dict):
-        self._event_handler_connector.send_message(message, key)
+        self._event_handler_connector.send_message(message)
+
+    @abstractmethod
+    def handle_trigger(self, message):
+        raise NotImplementedError
 
     # much secure, very cors, wow
     def check_origin(self, origin):
@@ -62,15 +73,19 @@ class ZMQWebSocketHandler(WebSocketHandler, ABC):
 
 class ZMQWebSocketProxy(ZMQWebSocketHandler):
     # pylint: disable=abstract-method
-    def initialize(self, make_response, proxy_filter):
+    def initialize(self, **kwargs): # pylint: disable=arguments-differ
-        # pylint: disable=arguments-differ
+        super(ZMQWebSocketProxy, self).initialize(**kwargs)
-        self._make_response = make_response
+        self._make_eventhandler_message = kwargs['make_eventhandler_message']
-        self._proxy_filter = proxy_filter
+        self._proxy_filter = kwargs['proxy_filter']
+        self._handle_trigger = kwargs['handle_trigger']
 
     def on_message(self, message):
         message = json.loads(message)
         if self._proxy_filter(message):
             super().on_message(message)
 
-    def make_response(self, message):
+    def make_eventhandler_message(self, message):
-        return self._make_response(message)
+        return self._make_eventhandler_message(message)
+
+    def handle_trigger(self, message):
+        self._handle_trigger(message)

lib/tfw/networking/zmq_connector_base.py

@@ -1,3 +1,6 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
 import zmq
 
 

nginx/components/login.conf

@@ -1,3 +0,0 @@
-location = /login {
-        proxy_pass http://127.0.0.1:${TFW_LOGIN_APP_PORT};
-    }

nginx/components/terminal.conf

@@ -3,4 +3,4 @@ location = /terminal {
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection "upgrade";
-    }
+}

nginx/nginx.conf

@@ -1,13 +1,11 @@
 worker_processes auto;
 pid /tmp/nginx.pid;
 
-events
+events {
-{
     worker_connections 1024;
 }
 
-http
+http {
-{
     sendfile on;
     tcp_nopush on;
     tcp_nodelay on;

supervisor/supervisord.conf

@@ -1,5 +1,5 @@
 [supervisord]
-user=user
+user=root
 logfile = /tmp/supervisord.log
 loglevel = debug
 pidfile = /tmp/supervisord.pid
@@ -18,9 +18,5 @@ command=/usr/sbin/nginx -g 'daemon off;'
 autostart=true
 autorestart=true
 
-[program:app]
-directory=%(ENV_TFW_APP_DIR)s
-command=python3 app.py
-
 [include]
 files=%(ENV_TFW_SUPERVISORD_COMPONENTS)s/*.conf