searx: New app for Searx metasearch engine

Signed-off-by: Joseph Nuthalapati <njoseph@thoughtworks.com>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>

LICENSES

@@ -70,3 +70,4 @@ otherwise.
 - static/themes/default/icons/windows.png :: [[https://thenounproject.com/icon/1206946/download/color/000000/png][CC BY 3.0 US]]
 - static/themes/default/icons/gnu-linux.png :: [[https://upload.wikimedia.org/wikipedia/commons/9/95/Tux-icon-mono.svg][Public Domain]]
 - static/themes/default/icons/mediawiki.svg :: [[http://tango.freedesktop.org/][Public Domain]]
+- static/themes/default/icons/searx.png :: [[https://github.com/asciimoo/searx/blob/master/searx/static/themes/simple/img/logo_searx_a.png][GPLv3+]]

actions/searx

@@ -0,0 +1,99 @@
+#!/usr/bin/python3
+# -*- mode: python -*-
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""
+Configuration helper for searx.
+"""
+
+import argparse
+import os
+
+from plinth import action_utils
+from plinth.utils import YAMLFile, gunzip
+
+
+def parse_arguments():
+    """Return parsed command line arguments as dictionary."""
+    parser = argparse.ArgumentParser()
+    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')
+
+    subparsers.add_parser('enable', help='Enable searx')
+    subparsers.add_parser('disable', help='Disable searx')
+    subparsers.add_parser(
+        'setup', help="Perform post-installation operations for Searx")
+
+    subparsers.required = True
+    return parser.parse_args()
+
+
+def _copy_uwsgi_configuration():
+    """Copy the example uwsgi configuration shipped with Searx to the
+    appropriate uwsgi directory."""
+    example_config = ('/usr/share/doc/searx/examples/'
+                      'uwsgi/apps-available/searx.ini')
+    destination = '/etc/uwsgi/apps-enabled/searx.ini'
+
+    if not os.path.exists(destination):
+        os.symlink(example_config, destination)
+        action_utils.webserver_enable('uwsgi', kind='module')
+
+
+def _generate_secret_key():
+    """ Generate a secret key for the Searx installation."""
+    settings_file = '/etc/searx/settings.yml'
+
+    # Create settings file if not exists
+    if not os.path.exists(settings_file):
+        example_settings_file = '/usr/share/doc/searx/examples/settings.yml.gz'
+        gunzip(example_settings_file, settings_file)
+
+    # Generate and set a secret key
+    with YAMLFile(settings_file) as settings:
+        secret_key = os.urandom(16).hex()
+        settings['server']['secret_key'] = secret_key
+
+    action_utils.service_restart('uwsgi')
+
+
+def subcommand_setup(_):
+    """Post installation actions for Searx"""
+    _copy_uwsgi_configuration()
+    _generate_secret_key()
+
+
+def subcommand_enable(_):
+    """Enable web configuration and reload."""
+    action_utils.webserver_enable('searx-plinth')
+
+
+def subcommand_disable(_):
+    """Disable web configuration and reload."""
+    action_utils.webserver_disable('searx-plinth')
+
+
+def main():
+    """Parse arguments and perform all duties."""
+    arguments = parse_arguments()
+
+    subcommand = arguments.subcommand.replace('-', '_')
+    subcommand_method = globals()['subcommand_' + subcommand]
+    subcommand_method(arguments)
+
+
+if __name__ == '__main__':
+    main()

data/etc/apache2/conf-available/searx-plinth.conf

@@ -0,0 +1,5 @@
+<Location /searx>
+    Options FollowSymLinks Indexes
+    SetHandler uwsgi-handler
+    uWSGISocket /run/uwsgi/app/searx/socket
+</Location>

data/etc/plinth/modules-enabled/searx

@@ -0,0 +1 @@
+plinth.modules.searx

plinth/modules/searx/__init__.py

@@ -0,0 +1,119 @@
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""
+Plinth module to configure Searx
+"""
+
+from django.utils.translation import ugettext_lazy as _
+
+from plinth import service as service_module
+from plinth import action_utils, actions, frontpage
+from plinth.menu import main_menu
+
+from .manifest import clients
+
+clients = clients
+
+version = 1
+
+managed_services = ['searx']
+
+managed_packages = [
+    'searx', 'uwsgi', 'uwsgi-plugin-python3', 'libapache2-mod-uwsgi'
+]
+
+name = _('Searx')
+
+short_description = _('Web Search')
+
+description = [
+    _('Searx is a privacy-respecting internet metasearch engine. '
+      'It aggregrates and displays results from multiple search engines.'),
+    _('Searx can be used to avoid tracking and profiling by search engines. '
+      'It stores no cookies by default. Additionally, Searx can be used over '
+      'Tor for online anonymity.'),
+    _('When enabled, Searx\'s web interface will be available from '
+      '<a href="/searx">/searx</a>.'),
+]
+
+service = None
+
+
+def init():
+    """Intialize the module."""
+    menu = main_menu.get('apps')
+    menu.add_urlname(name, 'glyphicon-search', 'searx:index',
+                     short_description)
+
+    global service
+    setup_helper = globals()['setup_helper']
+    if setup_helper.get_state() != 'needs-setup':
+        service = service_module.Service(managed_services[0], name, ports=[
+            'http', 'https'
+        ], is_external=True, is_enabled=is_enabled, enable=enable,
+                                         disable=disable)
+
+        if is_enabled():
+            add_shortcut()
+
+
+def setup(helper, old_version=None):
+    """Install and configure the module."""
+    helper.install(managed_packages)
+    helper.call('setup', actions.superuser_run, 'searx', ['setup'])
+    helper.call('post', actions.superuser_run, 'searx', ['enable'])
+    global service
+    if service is None:
+        service = service_module.Service(managed_services[0], name, ports=[
+            'http', 'https'
+        ], is_external=True, is_enabled=is_enabled, enable=enable,
+                                         disable=disable)
+    helper.call('post', add_shortcut)
+
+
+def add_shortcut():
+    """Helper method to add a shortcut to the frontpage."""
+    frontpage.add_shortcut('searx', name, short_description=short_description,
+                           url='/searx', login_required=True)
+
+
+def is_enabled():
+    """Return whether the module is enabled."""
+    return action_utils.webserver_is_enabled('searx-plinth')
+
+
+def enable():
+    """Enable the module."""
+    actions.superuser_run('searx', ['enable'])
+    add_shortcut()
+
+
+def disable():
+    """Disable the module."""
+    actions.superuser_run('searx', ['disable'])
+    frontpage.remove_shortcut('searx')
+
+
+def diagnose():
+    """Run diagnostics and return the results."""
+    results = []
+
+    results.extend(
+        action_utils.diagnose_url_on_all('https://{host}/searx/',
+                                         check_certificate=False))
+
+    return results

plinth/modules/searx/manifest.py

@@ -0,0 +1,28 @@
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+from django.utils.translation import ugettext_lazy as _
+
+from plinth.clients import validate
+
+clients = validate([{
+    'name': _('Searx'),
+    'platforms': [{
+        'type': 'web',
+        'url': '/searx'
+    }]
+}])

plinth/modules/searx/urls.py

@@ -0,0 +1,32 @@
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""
+URLs for the Searx module.
+"""
+
+from django.conf.urls import url
+
+from plinth.modules import searx
+from plinth.views import ServiceView
+
+urlpatterns = [
+    url(r'^apps/searx/$',
+        ServiceView.as_view(
+            service_id='searx', diagnostics_module_name='searx',
+            description=searx.description, clients=searx.clients,
+            show_status_block=False), name='index'),
+]

plinth/utils.py

@@ -18,6 +18,7 @@
 Miscellaneous utility methods.
 """
 
+import gzip
 import importlib
 import os
 import random
@@ -136,3 +137,21 @@ def grep(pattern, file_name):
     return [
         line.rstrip() for line in open(file_name) if re.search(pattern, line)
     ]
+
+
+def gunzip(gzip_file, output_file):
+    """Utility to unzip a given gzip file and write it to an output file
+
+    gzip_file: string path to a gzip file
+    output_file: string path to the output file
+    mode: an octal number to specify file permissions
+    """
+    output_dir = os.path.dirname(output_file)
+    if not os.path.exists(output_dir):
+        os.makedirs(output_dir, mode=0o755)
+
+    with gzip.open(gzip_file, 'rb') as f:
+        contents = f.read()
+    with open(output_file, 'wb') as f:
+        f.write(contents)
+    os.chmod(output_file, 0o644)