config: Add user websites as choices for homepage config.

Closes: #1981
Closes also most of threads in !1952.

Signed-off-by: Fioddor Superconcentrado <fioddor@gmail.com>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/apache/__init__.py

@@ -2,6 +2,7 @@
 """
 FreedomBox app for Apache server.
 """
+import os
 
 from django.utils.translation import ugettext_lazy as _
 
@@ -11,7 +12,7 @@ from plinth import cfg
 from plinth.daemon import Daemon
 from plinth.modules.firewall.components import Firewall
 from plinth.modules.letsencrypt.components import LetsEncrypt
-from plinth.utils import format_lazy
+from plinth.utils import format_lazy, is_valid_user_name
 
 version = 8
 
@@ -19,8 +20,9 @@ is_essential = True
 
 managed_services = ['apache2', 'uwsgi']
 
-managed_packages = ['apache2', 'php-fpm', 'ssl-cert', 'uwsgi',
+managed_packages = [
-                    'uwsgi-plugin-python3']
+    'apache2', 'php-fpm', 'ssl-cert', 'uwsgi', 'uwsgi-plugin-python3'
+]
 
 app = None
 
@@ -63,3 +65,81 @@ def setup(helper, old_version=None):
     actions.superuser_run(
         'apache',
         ['setup', '--old-version', str(old_version)])
+
+
+# (U)ser (W)eb (S)ites
+
+
+def uws_usr2dir(user):
+    """Returns the directory of the given user's website."""
+    return '/home/{}/public_html'.format(user)
+
+
+def uws_usr2url(user):
+    """Returns the url path of the given user's website."""
+    return '/~{}/'.format(user)
+
+
+def uws_dir2usr(directory):
+    """Returns the user of a given user website directory."""
+    if directory.startswith('/home/'):
+        pos_ini = 6
+    elif directory.startswith('home/'):
+        pos_ini = 5
+    else:
+        return None
+
+    pos_end = directory.find('/public_html')
+    if pos_end == -1:
+        return None
+
+    user = directory[pos_ini:pos_end]
+    return user if is_valid_user_name(user) else None
+
+
+def uws_url2usr(url):
+    """Returns the user of a given user website url path."""
+    MISSING = -1
+
+    pos_ini = url.find('~')
+    if pos_ini == MISSING:
+        return None
+
+    pos_end = url.find('/', pos_ini)
+    if pos_end == MISSING:
+        pos_end = len(url)
+
+    user = url[pos_ini + 1:pos_end]
+    return user if is_valid_user_name(user) else None
+
+
+def uws_url2dir(url):
+    """Returns the directory of the user's website for the given url path.
+
+    Note: It doesn't return the full OS file path to the url path!
+    """
+    return uws_usr2dir(uws_url2usr(url))
+
+
+def uws_dir2url(directory):
+    """Returns the url base path of the user's website for the given OS path.
+
+    Note: It doesn't return the url path for the file!
+    """
+    return uws_usr2url(uws_dir2usr(directory))
+
+
+def get_users_with_website():
+    """Returns a dictionary of users with actual website subdirectory."""
+
+    def lst_sub_dirs(directory):
+        """Returns the list of subdirectories of the given directory."""
+        return [
+            name for name in os.listdir(directory)
+            if os.path.isdir(os.path.join(directory, name))
+        ]
+
+    return {
+        name: uws_usr2url(name)
+        for name in lst_sub_dirs('/home') if os.path.isdir(uws_usr2dir(name))
+    }

plinth/modules/apache/tests/test_components.py

@@ -72,6 +72,7 @@ def test_webserver_disable(superuser_run):
 @patch('plinth.modules.apache.components.diagnose_url_on_all')
 def test_webserver_diagnose(diagnose_url_on_all, diagnose_url):
     """Test running diagnostics."""
+
     def on_all_side_effect(url, check_certificate):
         return [('test-result-' + url, 'success')]
 

plinth/modules/apache/tests/test_uws.py

@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""
+Test module for (U)ser (Web) (S)ites.
+"""
+
+from plinth.modules.apache import (uws_usr2dir, uws_dir2url, uws_url2usr,
+                                   uws_usr2url, uws_url2dir, uws_dir2usr)
+
+
+def test_uws_namings():
+    """Test name solvers for user, url and directory of UWS."""
+
+    assert '/home/usr/public_html' == uws_usr2dir('usr')
+    assert '/~usr/' == uws_usr2url('usr')
+
+    f = uws_dir2usr
+    assert f('/home/usr/lacks/the/UWS/directory') is None
+    assert 'usr' == f('/home/usr/public_html/is/a/normal/UWS/file')
+    assert 'usr' == f('/home/usr/public_html/is/a/normal/UWS/path/')
+    assert '€.;#@|' == f('/home/€.;#@|/public_html/is/stange/but/valid/')
+
+    f = uws_url2usr
+    assert f('/usr/is/not/a/valid/UWS/url/due/to/missing/tilde') is None
+    assert 'usr' == f('whatever/~usr/is/considered/a/valid/UWS/path')
+    assert 'usr' == f('~usr')
+    assert 'usr' == f('~usr/')
+    assert 'usr' == f('/~usr/')
+
+    assert '/home/usr/public_html' == uws_url2dir('~usr/any/file')
+    assert '/~usr/' == uws_dir2url('/home/usr/public_html/path/to/file')

plinth/modules/config/__init__.py

@@ -12,6 +12,8 @@ from django.utils.translation import ugettext_lazy as _
 from plinth import actions
 from plinth import app as app_module
 from plinth import frontpage, menu
+from plinth.modules.apache import (uws_url2usr, uws_usr2url,
+                                   get_users_with_website)
 from plinth.modules.names.components import DomainType
 from plinth.signals import domain_added
 
@@ -81,13 +83,56 @@ def get_hostname():
     return socket.gethostname()
 
 
-def _get_home_page_url():
+def home_page_url2scid(url):
+    """Returns the shortcut ID of the given home page url."""
+
+    if url in ('/plinth/', '/plinth', 'plinth'):
+        return 'plinth'
+
+    if url == '/index.html':
+        return 'apache-default'
+
+    if url and url.startswith('/~'):
+        return 'uws-{}'.format(uws_url2usr(url))
+
+    shortcuts = frontpage.Shortcut.list()
+    for shortcut in shortcuts:
+        if shortcut.url == url:
+            return shortcut.component_id
+
+    return None
+
+
+def _home_page_scid2url(shortcut_id):
+    """Returns the url for the given home page shortcut ID."""
+    if shortcut_id is None:
+        url = None
+    elif shortcut_id == 'plinth':
+        url = '/plinth/'
+    elif shortcut_id == 'apache-default':
+        url = '/index.html'
+    elif shortcut_id.startswith('uws-'):
+        user = shortcut_id[4:]
+        if user in get_users_with_website():
+            url = uws_usr2url(user)
+        else:
+            url = None
+    else:
+        shortcuts = frontpage.Shortcut.list()
+        aux = [
+            shortcut.url for shortcut in shortcuts
+            if shortcut_id == shortcut.component_id
+        ]
+        url = aux[0] if 1 == len(aux) else None
+
+    return url
+
+
+def _get_home_page_url(conf_file):
     """Get the default application for the domain."""
     aug = augeas.Augeas(flags=augeas.Augeas.NO_LOAD +
                         augeas.Augeas.NO_MODL_AUTOLOAD)
     aug.set('/augeas/load/Httpd/lens', 'Httpd.lns')
-    conf_file = APACHE_HOMEPAGE_CONFIG if os.path.exists(
-        APACHE_HOMEPAGE_CONFIG) else FREEDOMBOX_APACHE_CONFIG
     aug.set('/augeas/load/Httpd/incl[last() + 1]', conf_file)
     aug.load()
 
@@ -103,35 +148,20 @@ def _get_home_page_url():
 
 def get_home_page():
     """Return the shortcut ID that is set as current home page."""
-    url = _get_home_page_url()
+    CONF_FILE = APACHE_HOMEPAGE_CONFIG if os.path.exists(
-    if url in ['/plinth/', '/plinth', 'plinth']:
+        APACHE_HOMEPAGE_CONFIG) else FREEDOMBOX_APACHE_CONFIG
-        return 'plinth'
 
-    if url == '/index.html':
+    url = _get_home_page_url(CONF_FILE)
-        return 'apache-default'
+    return home_page_url2scid(url)
-
-    shortcuts = frontpage.Shortcut.list()
-    for shortcut in shortcuts:
-        if shortcut.url == url:
-            return shortcut.component_id
-
-    return None
 
 
 def change_home_page(shortcut_id):
     """Change the FreedomBox's default redirect to URL of the shortcut
        specified.
     """
-    if shortcut_id == 'plinth':
+    url = _home_page_scid2url(shortcut_id)
-        url = '/plinth/'
+    if url is None:
-    elif shortcut_id == 'apache-default':
+        url = '/plinth/'  	# fall back to default url if scid is unknown.
-        url = '/index.html'
-    else:
-        shortcuts = frontpage.Shortcut.list()
-        url = [
-            shortcut.url for shortcut in shortcuts
-            if shortcut.component_id == shortcut_id
-        ][0]
 
     # URL may be a reverse_lazy() proxy
     actions.superuser_run('config', ['set-home-page', str(url)])

plinth/modules/config/forms.py

@@ -14,6 +14,9 @@ from django.utils.translation import ugettext_lazy
 
 from plinth import cfg, frontpage
 from plinth.utils import format_lazy
+from plinth.modules.apache import get_users_with_website
+
+from . import home_page_url2scid
 
 logger = logging.getLogger(__name__)
 
@@ -32,9 +35,13 @@ def get_homepage_choices():
     shortcuts = frontpage.Shortcut.list(web_apps_only=True)
     shortcut_choices = [(shortcut.component_id, shortcut.name)
                         for shortcut in shortcuts if shortcut.is_enabled()]
+    uws_choices = \
+        [(home_page_url2scid(url),
+         format_lazy(ugettext_lazy("{user}'s website"), user=user))
+         for user, url in get_users_with_website().items()]
     apache_default = ('apache-default', _('Apache Default'))
     plinth = ('plinth', _('FreedomBox Service (Plinth)'))
-    return [apache_default, plinth] + shortcut_choices
+    return [apache_default, plinth] + uws_choices + shortcut_choices
 
 
 class ConfigurationForm(forms.Form):

plinth/modules/config/tests/test_config.py

@@ -3,11 +3,16 @@
 Tests for config module.
 """
 
+import pytest
 import os
 
-from plinth import __main__ as plinth_main
+from unittest.mock import (patch, MagicMock)
 
-from ..forms import ConfigurationForm
+from plinth import __main__ as plinth_main
+from plinth.modules.apache import uws_usr2dir
+from plinth.modules.config import (home_page_url2scid, get_home_page,
+                                   _home_page_scid2url, change_home_page)
+from plinth.modules.config.forms import ConfigurationForm
 
 
 def test_hostname_field():
@@ -64,6 +69,111 @@ def test_domainname_field():
         assert not form.is_valid()
 
 
+def test_homepage_mapping():
+    """Basic tests for homepage functions."""
+    f = home_page_url2scid
+    assert f(None) is None
+    assert f('/unknown/url') is None
+    assert 'plinth' == f('/plinth/')
+    assert 'plinth' == f('/plinth')
+    assert 'plinth' == f('plinth')
+    assert 'apache-default' == f('/index.html')
+    assert 'uws-user' == f('/~user')
+    assert 'uws-user' == f('/~user/whatever/else')
+    # assert 'config' == f('/plinth/apps/sharing/')
+
+    f = _home_page_scid2url
+    assert f(None) is None
+    assert '/plinth/' == f('plinth')
+    assert '/index.html' == f('apache-default')
+
+
+def test_homepage_mapping_skip_ci():
+    """Special tests for homepage functions."""
+
+    try:
+        UWS_DIRECTORY = uws_usr2dir(os.getlogin())
+    except OSError:
+        reason = "Needs access to ~/ directory. " \
+               + "CI sandboxed workspace doesn't provide it."
+        pytest.skip(reason)
+
+    if os.path.exists(UWS_DIRECTORY):
+        reason = "UWS dir {} exists already.".format(UWS_DIRECTORY)
+        pytest.skip(reason)
+
+    f = _home_page_scid2url
+    os.mkdir(UWS_DIRECTORY)
+    assert '/~fbx/' == f('uws-fbx')
+    os.rmdir(UWS_DIRECTORY)
+    assert f('uws-fbx') is None
+
+
+class Dict2Obj(object):
+    """Mock object made out of any dict."""
+
+    def __init__(self, a_dict):
+        self.__dict__ = a_dict
+
+
+@patch('plinth.frontpage.Shortcut.list', MagicMock(return_value=[
+            Dict2Obj({'url': 'url/for/'+id, 'component_id': id})
+            for id in ('a', 'b')
+        ]))
+def test_homepage_field():
+    """Test homepage changes.
+
+    Test Cases:
+        1) FreedomBox Homepage (default),
+        2) Apache default,
+        3) A user's website of an...
+        3.1) unexisting user
+        3.2) existing user without a page
+        3.3) existing user page.
+        4) A FreedomBox App.
+        4.1) unknown app
+        4.2) uninstalled app
+        4.3) disabled app
+        4.4) enabled app
+
+    Note: If run on a pristine unconfigured FreedomBox, this test will leave
+          the homepage default-configured. (Imperfect cleanup in such case).
+
+    Pending: Specific test cases to distiguish 4.1,2,3.
+             Currently they share the same test case.
+    """
+    try:
+        UWS_DIRECTORY = uws_usr2dir(os.getlogin())
+    except OSError:
+        reason = "Needs access to ~/ directory, etc. " \
+               + "CI sandboxed workspace doesn't provide it."
+        pytest.skip(reason)
+
+    DEFAULT_HOME_PAGE = 'plinth'
+    ORIGINAL_HOME_PAGE = get_home_page() or DEFAULT_HOME_PAGE
+
+    if ORIGINAL_HOME_PAGE not in (DEFAULT_HOME_PAGE, None):
+        reason = "Unexpected home page {}.".format(ORIGINAL_HOME_PAGE)
+        pytest.skip(reason)
+
+    # invalid changes fall back to default:
+    for scid in ('uws-unexisting', 'uws-fbx', 'missing_app'):
+        change_home_page(scid)
+        assert get_home_page() == DEFAULT_HOME_PAGE
+
+    os.mkdir(UWS_DIRECTORY)
+
+    # valid changes actually happen:
+    for scid in ('b', 'a', 'uws-fbx', 'apache-default', 'plinth'):
+        change_home_page(scid)
+        assert get_home_page() == scid
+
+    # cleanup:
+    change_home_page(ORIGINAL_HOME_PAGE)
+    os.rmdir(UWS_DIRECTORY)
+    assert get_home_page() == ORIGINAL_HOME_PAGE
+
+
 def test_locale_path():
     """
     Test that the 'locale' directory is in the same folder as __main__.py.

plinth/tests/test_utils.py

@@ -10,11 +10,26 @@ import pytest
 import ruamel.yaml
 from django.test.client import RequestFactory
 
-from plinth.utils import YAMLFile, is_user_admin
+from plinth.utils import YAMLFile, is_user_admin, is_valid_user_name
+
+
+def test_is_valid_user_name():
+    """Test valid user names in Debian."""
+    f = is_valid_user_name
+    assert not f('this_user_name_is_too_long_to_be_valid')
+    assert not f('-invalid')
+    assert not f('not\tvalid')
+    assert not f('not\nvalid')
+    assert not f('not valid')
+    assert not f('not:valid')
+    assert not f('not/valid')
+    assert not f('not\\valid')
+    assert f('€.;#@|')
 
 
 class TestIsAdminUser:
     """Test class for is_user_admin utility."""
+
     @staticmethod
     @pytest.fixture(name='web_request')
     def fixture_web_request():

plinth/utils.py

@@ -58,6 +58,24 @@ def user_group_view(func, group_name):
     return func
 
 
+def is_valid_user_name(user_name):
+    """Check if the given username is valid.
+
+    Note: Debian is VERY flexible with user names.
+    """
+    if 32 < len(user_name):
+        return False
+
+    if user_name.startswith('-'):
+        return False
+
+    for forbidden in (' \n\t/\\:'):
+        if forbidden in user_name:
+            return False
+
+    return True
+
+
 def is_user_admin(request, cached=False):
     """Return whether user is an administrator."""
     if not request.user.is_authenticated: