flask task solution

README.md

@@ -10,6 +10,9 @@ This Python app allows user to do via CLI:
 * List labels for given repository
 * Run update/replace labels for multiple projects (labels are specified in configuration file or by template repo)
 
+App allows you run master-to-master replication web server which works with GitHub webhooks and manage labels for multiple repositories in even simpler way (try `run_server` command and see landing page for more information)!
+
+
 For more information please use `--help`.
 
 This project is reference solution for Labelord tasks series in [cvut/MI-PYT](https://github.com/cvut/MI-PYT).

config.example.cfg

@@ -10,6 +10,9 @@
 # optionally you can provide token via
 # GITHUB_TOKEN env variable
 token = MY_GITHUB_TOKEN
+# Secret used for securing webhooks
+# see: https://developer.github.com/webhooks/securing/
+webhook_secret = MY_WEBHOOK_SECRET
 
 # Specify labels with list:
 [labels]

labelord.py

@@ -1,8 +1,12 @@
 import click
 import configparser
+import flask
+import hashlib
+import hmac
 import os
 import requests
 import sys
+import time
 
 
 DEFAULT_SUCCESS_RETURN = 0
@@ -113,6 +117,11 @@ def delete_label(self, repository, name, **kwargs):
         if response.status_code != 204:
             raise GitHubError(response)
 
+    @staticmethod
+    def webhook_verify_signature(data, signature, secret, encoding='utf-8'):
+        h = hmac.new(secret.encode(encoding), data, hashlib.sha1)
+        return hmac.compare_digest('sha1=' + h.hexdigest(), signature)
+
 ###############################################################################
 # Printing and logging
 ###############################################################################
@@ -352,6 +361,184 @@ def retrieve_github_client(ctx):
         sys.exit(NO_GH_TOKEN_RETURN)
     return ctx.obj['GitHub']
 
+###############################################################################
+# Flask task
+###############################################################################
+
+
+class LabelordChange:
+    CHANGE_TIMEOUT = 10
+
+    def __init__(self, action, name, color, new_name=None):
+        self.action = action
+        self.name = name
+        self.color = None if action == 'deleted' else color
+        self.old_name = new_name
+        self.timestamp = int(time.time())
+
+    @property
+    def tuple(self):
+        return self.action, self.name, self.color, self.old_name
+
+    def __eq__(self, other):
+        return self.tuple == other.tuple
+
+    def is_valid(self):
+        return self.timestamp > (int(time.time()) - self.CHANGE_TIMEOUT)
+
+
+class LabelordWeb(flask.Flask):
+
+    def __init__(self, labelord_config, github, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.labelord_config = labelord_config
+        self.github = github
+        self.ignores = {}
+
+    def inject_session(self, session):
+        self.github.set_session(session)
+
+    def reload_config(self):
+        config_filename = os.environ.get('LABELORD_CONFIG', None)
+        self.labelord_config = create_config(
+            token=os.getenv('GITHUB_TOKEN', None),
+            config_filename=config_filename
+        )
+        self._check_config()
+        self.github.token = self.labelord_config.get('github', 'token')
+
+    @property
+    def repos(self):
+        return extract_repos(flask.current_app.labelord_config)
+
+    def _check_config(self):
+        if not self.labelord_config.has_option('github', 'token'):
+            click.echo('No GitHub token has been provided', err=True)
+            sys.exit(NO_GH_TOKEN_RETURN)
+        if not self.labelord_config.has_section('repos'):
+            click.echo('No repositories specification has been found',
+                       err=True)
+            sys.exit(NO_REPOS_SPEC_RETURN)
+        if not self.labelord_config.has_option('github', 'webhook_secret'):
+            click.echo('No webhook secret has been provided', err=True)
+            sys.exit(NO_WEBHOOK_SECRET_RETURN)
+
+    def _init_error_handlers(self):
+        from werkzeug.exceptions import default_exceptions
+        for code in default_exceptions:
+            self.errorhandler(code)(LabelordWeb._error_page)
+
+    def finish_setup(self):
+        self._check_config()
+        self._init_error_handlers()
+
+    @staticmethod
+    def create_app(config=None, github=None):
+        cfg = config or create_config(
+            token=os.getenv('GITHUB_TOKEN', None),
+            config_filename=os.getenv('LABELORD_CONFIG', None)
+        )
+        gh = github or GitHub('')  # dummy, but will be checked later
+        gh.token = cfg.get('github', 'token', fallback='')
+        return LabelordWeb(cfg, gh, import_name=__name__)
+
+    @staticmethod
+    def _error_page(error):
+        return flask.render_template('error.html', error=error), error.code
+
+    def cleanup_ignores(self):
+        for repo in self.ignores:
+            self.ignores[repo] = [c for c in self.ignores[repo]
+                                  if c.is_valid()]
+
+    def process_label_webhook_create(self, label, repo):
+        self.github.create_label(repo, label['name'], label['color'])
+
+    def process_label_webhook_delete(self, label, repo):
+        self.github.delete_label(repo, label['name'])
+
+    def process_label_webhook_edit(self, label, repo, changes):
+        name = old_name = label['name']
+        color = label['color']
+        if 'name' in changes:
+            old_name = changes['name']['from']
+        self.github.update_label(repo, name, color, old_name)
+
+    def process_label_webhook(self, data):
+        self.cleanup_ignores()
+        action = data['action']
+        label = data['label']
+        repo = data['repository']['full_name']
+        flask.current_app.logger.info(
+            'Processing LABEL webhook event with action {} from {} '
+            'with label {}'.format(action, repo, label)
+        )
+        if repo not in self.repos:
+            return  # This repo is not being allowed in this app
+
+        change = LabelordChange(action, label['name'], label['color'])
+        if action == 'edited' and 'name' in data['changes']:
+            change.new_name = label['name']
+            change.name = data['changes']['name']['from']
+
+        if repo in self.ignores and change in self.ignores[repo]:
+            self.ignores[repo].remove(change)
+            return  # This change was initiated by this service
+        for r in self.repos:
+            if r == repo:
+                continue
+            if r not in self.ignores:
+                self.ignores[r] = []
+            self.ignores[r].append(change)
+            try:
+                if action == 'created':
+                    self.process_label_webhook_create(label, r)
+                elif action == 'deleted':
+                    self.process_label_webhook_delete(label, r)
+                elif action == 'edited':
+                    self.process_label_webhook_edit(label, r, data['changes'])
+            except GitHubError:
+                pass  # Ignore GitHub errors
+
+
+app = LabelordWeb.create_app()
+
+
+@app.before_first_request
+def finalize_setup():
+    flask.current_app.finish_setup()
+
+
+@app.route('/', methods=['GET'])
+def index():
+    repos = flask.current_app.repos
+    return flask.render_template('index.html', repos=repos)
+
+
+@app.route('/', methods=['POST'])
+def hook_accept():
+    headers = flask.request.headers
+    signature = headers.get('X-Hub-Signature', '')
+    event = headers.get('X-GitHub-Event', '')
+    data = flask.request.get_json()
+
+    if not flask.current_app.github.webhook_verify_signature(
+            flask.request.data, signature,
+            flask.current_app.labelord_config.get('github', 'webhook_secret')
+    ):
+        flask.abort(401)
+
+    if event == 'label':
+        if data['repository']['full_name'] not in flask.current_app.repos:
+            flask.abort(400, 'Repository is not allowed in application')
+        flask.current_app.process_label_webhook(data)
+        return ''
+    if event == 'ping':
+        flask.current_app.logger.info('Accepting PING webhook event')
+        return ''
+    flask.abort(400, 'Event not supported')
+
+
 ###############################################################################
 # Click commands
 ###############################################################################
@@ -361,8 +548,8 @@ def retrieve_github_client(ctx):
 @click.option('--config', '-c', type=click.Path(exists=True),
               help='Path of the auth config file.')
 @click.option('--token', '-t', envvar='GITHUB_TOKEN',
-              help='GitHub API token.')  # prompt would be better,
-@click.version_option(version='0.1',
+              help='GitHub API token.')
+@click.version_option(version='0.2',
                       prog_name='labelord')
 @click.pass_context
 def cli(ctx, config, token):
@@ -438,5 +625,19 @@ def run(ctx, mode, template_repo, dry_run, verbose, quiet, all_repos):
         sys.exit(gh_error_return(error))
 
 
+@cli.command(help='Run master-to-master replication server.')
+@click.option('--host', '-h', default='127.0.0.1',
+              help='The interface to bind to.')
+@click.option('--port', '-p', default=5000,
+              help='The port to bind to.')
+@click.option('--debug', '-d', is_flag=True,
+              help='Turns on DEBUG mode.')
+@click.pass_context
+def run_server(ctx, host, port, debug):
+    app.labelord_config = ctx.obj['config']
+    app.github = retrieve_github_client(ctx)
+    app.run(host=host, port=port, debug=debug)
+
+
 if __name__ == '__main__':
     cli(obj={})

requirements.txt

@@ -1,3 +1,5 @@
 configparser
 click
 requests
+flask
+werkzeug

static/style.css

@@ -0,0 +1,12 @@
+html,
+body {
+    height: 100%;
+}
+body{
+    padding-top: 60px;
+}
+.colorbox{
+    width: 1.5em;
+    height: 1.5em;
+    border: 1px solid black;
+}

templates/error.html

@@ -0,0 +1,9 @@
+{% extends "layout.html" %}
+{% block body %}
+<div class="jumbotron" id="landing-info">
+    <h1>Something went wrong!</h1>
+    <hr>
+    <h2>Error {{ error.code }}</h2>
+    <p>{{ error.description }}</p>
+</div>
+{% endblock %}

templates/header.html

@@ -0,0 +1,23 @@
+<nav class="navbar navbar-default navbar-fixed-top navbar-inverse">
+    <div class="container">
+        <div class="navbar-header">
+            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar"
+                    aria-expanded="false" aria-controls="navbar">
+                <span class="sr-only">Toggle navigation</span>
+                <span class="icon-bar"></span>
+                <span class="icon-bar"></span>
+                <span class="icon-bar"></span>
+            </button>
+            <a class="navbar-logo" href="{{ url_for('index') }}">
+                <span class="navbar-brand"><span class="octicon octicon-radio-tower"></span> Labelord server</span>
+            </a>
+        </div>
+        <div id="navbar" class="navbar-collapse collapse">
+            <ul class="nav navbar-nav navbar-right">
+                <li>
+                    <a href="{{ url_for('index') }}"><span class="octicon octicon-home"></span> Home</a>
+                </li>
+            </ul>
+        </div><!--/.nav-collapse -->
+    </div>
+</nav>

templates/index.html

@@ -0,0 +1,52 @@
+{% extends "layout.html" %}
+{% block body %}
+<div class="jumbotron" id="landing-info">
+    <h1>Welcome!</h1>
+    <hr>
+    <p>
+        <em>Labelord</em> is simple tool for management of issue labels for GitHub repositories.
+        Server part serves for master-to-master replication of labels thanks to webhooks. It propagates
+        labels changes within group of selected repositories. Cool huh?!
+    </p>
+
+    <p>
+        This project has started as a semester work during advanced Python course
+        <a href="https://github.com/cvut/MI-PYT/" target="_blank">MI-PYT @ FIT CTU in Prague</a>.
+    </p>
+
+    <hr>
+
+    <h2>Instructions</h2>
+
+        Create webhook @GitHub for your repositories with:
+    <dl class="dl-horizontal">
+        <dt>Payload URL</dt>
+        <dd><code>{{ url_for('hook_accept', _external=True) }}</code></dd>
+        <dt>Content type</dt>
+        <dd><code>application/json</code></dd>
+        <dt>Secret</dt>
+        <dd>The secret from config file!</dd>
+        <dt>Content type</dt>
+        <dd>Select event <strong>Label</strong> or more...</dd>
+    </dl>
+
+    <hr>
+
+    <h2>Repositories</h2>
+    <p>
+        Application is running currently for following repositories (from config file):
+    </p>
+
+    <table class="table table-striped">
+        {% for repo in repos %}
+        <tr>
+            <td>{{ repo }}</td>
+            <td align="right">
+                <a href="https://github.com/{{ repo }}" target="_blank" class="btn btn-primary"><span
+                        class="octicon octicon-octoface"></span> GitHub</a>
+            </td>
+        </tr>
+        {% endfor %}
+    </table>
+</div>
+{% endblock %}

templates/layout.html

@@ -0,0 +1,25 @@
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="author" content="Marek Suchánek">
+    <title>Labelord</title>
+
+    <link rel="stylesheet" href="{{ url_for('static', filename='bootstrap.min.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
+
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/octicons/4.4.0/octicons.min.css"/>
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/octicons/4.4.0/font/octicons.min.css"/>
+</head>
+<body>
+    <main>
+        <div id="content">
+            <div class="container">
+                {% include "header.html" %}
+
+                {% block body %}{% endblock %}
+            </div>
+        </div>
+    </main>
+    {% block scripts %}{% endblock %}
+</body>
+</html>