put things into proper directories

1 files changed, 0 insertions, 549 deletions

diff --git a/app.py b/app.py
deleted file mode 100755
index 5af55af..0000000
--- a/app.py
+++ /dev/null
@@ -1,549 +0,0 @@
-#!/usr/bin/env python3
-
-# Copyright (c) 2021 Egor Tensin <Egor.Tensin@gmail.com>
-# This file is part of the "linux-status" project.
-# For details, see https://github.com/egor-tensin/linux-status.
-# Distributed under the MIT License.
-
-# Initially it was just index.html and a bunch of shell scripts in cgi-bin.
-# The web server could be launched using just `python -m http.server --cgi`,
-# and all was well.  Until I decided that I want to package this little app
-# of mine so that it can be easily installed and run on a variety of systems.
-# There was a problem with that, however: the app was designed to be run by
-# a regular user, not root (mostly due to all the `systemctl --user` calls),
-# and it didn't play nicely with the whole package idea.  Plus, I've long
-# wanted to make it show all the systemd user instances, not just the running
-# user's.  In addition, I wanted to dedupe the small chunks of code in cgi-bin.
-#
-# So this script was born.  It could handle a lot more complexity than the
-# shell scripts; it could be run as root and as a regular user, etc.  It was
-# still a CGI script (and it still is BTW), and a separate Python instance was
-# used by the web server to execute it.
-#
-# There was a problem, of course.  The thing is, I for once had a very strict
-# performance requirement for this script: it had to work nicely on my rather
-# old Raspberry Pi 1 Model B+.  It, being a Python script, didn't.  After
-# some investigation, it was obvious that the main problem were the imports
-# (especially those of the cgi & logging modules); they would take more time
-# than the interval between requests.  So I had to find a way to make it more
-# performant.
-#
-# I played with Lua for a bit, but couldn't quite make it work in a
-# satisfactory way.  Then I had an idea: I could use http.server's HTTP server
-# classes, overriding them to handle the "CGI" requests using the code in this
-# script.  That way, the imports would only be done once for the entire life
-# of the server.  In addition, no more tricks with sudo were required
-# (http.server runs CGI scripts as user nobody, which is a no-no for this app;
-# some trickery like whitelisting nobody in /etc/sudoers.d were employed).
-#
-# So that's where we are now, and it works!  Doesn't load my good ol' Raspberry
-# no more.
-
-import abc
-import cgi
-from collections import namedtuple
-from concurrent.futures import ThreadPoolExecutor
-from enum import Enum
-import http.server
-import json
-import os
-import pwd
-import shlex
-import socket
-import subprocess
-from subprocess import DEVNULL, PIPE, STDOUT
-
-
-def split_by(xs, sep):
-    group = []
-    for x in xs:
-        if x == sep:
-            yield group
-            group = []
-        else:
-            group.append(x)
-    yield group
-
-
-class Response:
-    DEFAULT_STATUS = http.server.HTTPStatus.OK
-
-    @staticmethod
-    def body_from_json(body):
-        return json.dumps(body, ensure_ascii=False, indent=4)
-
-    def __init__(self, body, status=None):
-        if status is None:
-            status = Response.DEFAULT_STATUS
-        self.status = status
-        self.body = body
-
-    def headers(self):
-        yield 'Content-Type', 'text/html; charset=utf-8'
-
-    def encode_body(self):
-        return self.body.encode(errors='replace')
-
-    def write_as_cgi_script(self):
-        self.write_headers_as_cgi_script()
-        self.write_body_as_cgi_script()
-
-    def write_headers_as_cgi_script(self):
-        for name, val in self.headers():
-            print(f'{name}: {val}')
-        print()
-
-    def write_body_as_cgi_script(self):
-        if self.body is not None:
-            print(self.body)
-
-    def write_to_request_handler(self, handler):
-        handler.send_response(self.status)
-        self.write_headers_to_request_handler(handler)
-        self.write_body_to_request_handler(handler)
-
-    def write_headers_to_request_handler(self, handler):
-        for name, val in self.headers():
-            handler.send_header(name, val)
-        handler.end_headers()
-
-    def write_body_to_request_handler(self, handler):
-        if self.body is not None:
-            handler.wfile.write(self.encode_body())
-
-
-def run_do(*args, **kwargs):
-    output = subprocess.run(args, stdin=DEVNULL, stdout=PIPE, stderr=STDOUT, universal_newlines=True, **kwargs)
-    # Include the output in the exception's message:
-    try:
-        output.check_returncode()
-    except Exception as e:
-        raise RuntimeError("Command's output was this:\n" + output.stdout) from e
-    return output.stdout
-
-
-class Task(abc.ABC):
-    def complete(self):
-        self.run()
-        return Response(Response.body_from_json(self.result()))
-
-    @abc.abstractmethod
-    def run(self):
-        pass
-
-    @abc.abstractmethod
-    def result(self):
-        pass
-
-
-class TaskList(Task):
-    def __init__(self, tasks):
-        self.tasks = tasks
-
-    def add(self, name, task):
-        if name in self.tasks:
-            raise RuntimeError(f'duplicate task name: {name}')
-        self.tasks[name] = task
-
-    def run(self):
-        for task in self.tasks.values():
-            task.run()
-
-    def result(self):
-        return {name: task.result() for name, task in self.tasks.items()}
-
-
-pool = ThreadPoolExecutor()
-
-
-def run(*args, **kwargs):
-    return pool.submit(run_do, *args, **kwargs)
-
-
-class Command(Task):
-    def __init__(self, *args):
-        self.args = args
-        self.env = None
-
-    def run(self):
-        self.task = run(*self.args, env=self.env)
-        return self.task
-
-    def result(self):
-        return self.task.result()
-
-    def now(self):
-        return self.run().result()
-
-
-class Systemd(Command):
-    def __init__(self, *args):
-        super().__init__(*args)
-        self.env = self.make_env()
-
-    @staticmethod
-    def make_env():
-        env = os.environ.copy()
-        env['SYSTEMD_PAGER'] = ''
-        env['SYSTEMD_COLORS'] = 'no'
-        return env
-
-    @staticmethod
-    def su(user, cmd):
-        new = Systemd('su', '-c', shlex.join(cmd.args), user.name)
-        new.env = Systemd.fix_su_env(user, cmd.env.copy())
-        return new
-
-    @staticmethod
-    def fix_su_env(user, env):
-        # https://unix.stackexchange.com/q/483948
-        # https://unix.stackexchange.com/q/346841
-        # https://unix.stackexchange.com/q/423632
-        # https://unix.stackexchange.com/q/245768
-        # https://unix.stackexchange.com/q/434494
-        env['XDG_RUNTIME_DIR'] = user.runtime_dir
-        # I'm not sure the bus part works everywhere.
-        bus_path = os.path.join(user.runtime_dir, 'bus')
-        env['DBUS_SESSION_BUS_ADDRESS'] = 'unix:path=' + bus_path
-        return env
-
-
-class Ctl(Systemd):
-    def __init__(self, executable, *args):
-        super().__init__(executable, *args, '--full')
-
-    @classmethod
-    def system(cls, *args):
-        return cls('--system', *args)
-
-    @classmethod
-    def user(cls, *args):
-        return cls('--user', *args)
-
-
-class Systemctl(Ctl):
-    def __init__(self, *args):
-        super().__init__('systemctl', *args)
-
-
-class Journalctl(Ctl):
-    def __init__(self, *args):
-        super().__init__('journalctl', *args)
-
-
-class Loginctl(Systemd):
-    def __init__(self, *args):
-        super().__init__('loginctl', *args, '--full')
-
-
-class Docker(Command):
-    def __init__(self, *args):
-        super().__init__('docker', *args)
-
-
-class DockerVersion(Docker):
-    def __init__(self, *args):
-        super().__init__('version')
-
-    @staticmethod
-    def is_daemon_running():
-        try:
-            DockerVersion().now()
-            return True
-        except:
-            return False
-
-
-class DockerPs(Docker):
-    def __init__(self, *args):
-        super().__init__('ps', *args)
-
-    @staticmethod
-    def quiet(*args):
-        return DockerPs('--quiet', *args)
-
-    @staticmethod
-    def get_all_ids():
-        cmd = DockerPs.quiet('--all')
-        return cmd.now().splitlines()
-
-
-class DockerInspect(Docker):
-    # This is pretty cool.  I wanted to separate container entries with \0, and
-    # this is the best I could come up with.  Note that a newline still gets
-    # added at the end.
-    FORMAT = '{{printf "%s%c" (json .) 0}}'
-
-    def __init__(self, *args):
-        super().__init__('inspect', f'--format={DockerInspect.FORMAT}', *args)
-
-
-class DockerStatus(DockerInspect):
-    def __init__(self):
-        self.containers = DockerPs.get_all_ids()
-        super().__init__(*self.containers)
-
-    def run(self):
-        if not self.containers:
-            # `docker inspect` requires at least one container argument.
-            return ''
-        return super().run()
-
-    def result(self):
-        if not self.containers:
-            # `docker inspect` requires at least one container argument.
-            return []
-        result = super().result()
-        result = result.split('\0')
-        result = [json.loads(info) for info in result if info.strip()]
-        result = [DockerStatus.filter_info(info) for info in result]
-        return result
-
-    @staticmethod
-    def filter_info(info):
-        assert info['Name'][0] == '/'
-        return {
-            'exit_code': info['State']['ExitCode'],
-            'health': info['State'].get('Health', {}).get('Status', None),
-            'image': info['Config']['Image'],
-            # Strip the leading /:
-            'name': info['Name'][1:],
-            'started_at': info['State']['StartedAt'],
-            'status': info['State']['Status'],
-        }
-
-class Hostname(Task):
-    def run(self):
-        pass
-
-    def result(self):
-        return socket.gethostname()
-
-
-class Top(Command):
-    COMMAND = None
-
-    def __init__(self):
-        super().__init__(*Top.get_command())
-
-    @staticmethod
-    def get_command():
-        # On more modern versions of top, we want to enable memory scaling
-        # from the command line (another option is the rc file, but that's too
-        # complicated).  For that, we simply run `top -h` once, and check if
-        # the output contains the flags we want to use.
-        if Top.COMMAND is not None:
-            return Top.COMMAND
-        help_output = run_do('top', '-h')
-        args = ['top', '-b', '-n', '1', '-w', '512']
-        if 'Ee' in help_output:
-            args += ['-E', 'm', '-e', 'm']
-        Top.COMMAND = args
-        return Top.COMMAND
-
-
-class Reboot(Command):
-    def __init__(self):
-        super().__init__('systemctl', 'reboot')
-
-
-class Poweroff(Command):
-    def __init__(self):
-        super().__init__('systemctl', 'poweroff')
-
-
-class InstanceStatus(TaskList):
-    def __init__(self, systemctl, journalctl):
-        tasks = {
-            'overview': systemctl('status'),
-            'failed': systemctl('list-units', '--failed'),
-            'timers': systemctl('list-timers', '--all'),
-            'journal': journalctl('-b', '--lines=20'),
-        }
-        super().__init__(tasks)
-
-
-class SystemStatus(InstanceStatus):
-    def __init__(self):
-        super().__init__(Systemctl.system, Journalctl.system)
-        if DockerVersion.is_daemon_running():
-            self.add('docker', DockerStatus())
-
-
-class UserStatus(InstanceStatus):
-    def __init__(self, systemctl=Systemctl.user, journalctl=Journalctl.user):
-        super().__init__(systemctl, journalctl)
-
-    @staticmethod
-    def su(user):
-        systemctl = lambda *args: Systemd.su(user, Systemctl.user(*args))
-        journalctl = lambda *args: Systemd.su(user, Journalctl.user(*args))
-        return UserStatus(systemctl, journalctl)
-
-
-class UserStatusList(TaskList):
-    def __init__(self):
-        if running_as_root():
-            # As root, we can query all the user instances.
-            tasks = {user.name: UserStatus.su(user) for user in systemd_users()}
-        else:
-            # As a regular user, we can only query ourselves.
-            tasks = {}
-            user = get_current_user()
-            if user_instance_active(user):
-                tasks[user.name] = UserStatus()
-        super().__init__(tasks)
-
-
-class Status(TaskList):
-    def __init__(self):
-        tasks = {
-            'hostname': Hostname(),
-            'system': SystemStatus(),
-            'user': UserStatusList(),
-        }
-        super().__init__(tasks)
-
-
-User = namedtuple('User', ['uid', 'name'])
-SystemdUser = namedtuple('SystemdUser', ['uid', 'name', 'runtime_dir'])
-
-
-def running_as_root():
-    # AFAIK, Python's http.server drops root privileges and executes the scripts
-    # as user nobody.
-    # It does no such thing if run as a regular user though.
-    return os.geteuid() == 0 or running_as_nobody()
-
-
-def running_as_nobody():
-    for user in users():
-        if user.name == 'nobody':
-            return user.uid == os.geteuid()
-    return False
-
-
-def get_current_user():
-    uid = os.getuid()
-    entry = pwd.getpwuid(uid)
-    return User(entry.pw_uid, entry.pw_name)
-
-
-def user_instance_active(user):
-    # I'm pretty sure this is the way to determine if the user instance is
-    # running?
-    # Source: https://www.freedesktop.org/software/systemd/man/user@.service.html
-    unit_name = f'user@{user.uid}.service'
-    cmd = Systemctl.system('is-active', unit_name, '--quiet')
-    try:
-        cmd.now()
-        return True
-    except Exception:
-        return False
-
-
-# A pitiful attempt to find a list of possibly-systemd-enabled users follows
-# (i.e. users that might be running a per-user systemd instance).
-# I don't know of a better way than probing /run/user/UID.
-# Maybe running something like `loginctl list-sessions` would be better?
-
-# These are the default values, see [1].
-# The actual values are specified in /etc/login.defs.
-# Still, they can be overridden on the command line, so I don't think there
-# actually is a way to list non-system users (imma call them "human").
-#
-#   [1]: https://man7.org/linux/man-pages/man8/useradd.8.html
-UID_MIN = 1000
-UID_MAX = 60000
-
-
-def users():
-    for entry in pwd.getpwall():
-        yield User(entry.pw_uid, entry.pw_name)
-
-
-def human_users():
-    for user in users():
-        if user.uid < UID_MIN:
-            continue
-        if user.uid > UID_MAX:
-            continue
-        yield user
-
-
-# You know what, loginctl might just be the answer.
-# Namely, `loginctl list-users`: during my testing, it did only list the users
-# that were running a systemd instance.
-def systemd_users():
-    def list_users():
-        output = Loginctl('list-users', '--no-legend').now()
-        lines = output.splitlines()
-        if not lines:
-            return
-        for line in lines:
-            # This assumes user names cannot contain spaces.
-            # loginctl list-users output must be in the UID NAME format.
-            info = line.lstrip().split(' ', 2)
-            if len(info) < 2:
-                raise RuntimeError(f'invalid `loginctl list-users` output:\n{output}')
-            uid, user = info[0], info[1]
-            yield User(uid, user)
-
-    def show_users(users):
-        user_args = [user.name for user in users]
-        if not user_args:
-            return None
-        properties = 'UID', 'Name', 'RuntimePath'
-        prop_args = (arg for prop in properties for arg in ('-p', prop))
-        output = Loginctl('show-user', *prop_args, '--value', *user_args).now()
-        lines = output.splitlines()
-        # Assuming that for muptiple users, the properties will be separated by
-        # an empty string.
-        groups = split_by(lines, '')
-        for group in groups:
-            if len(group) != len(properties):
-                raise RuntimeError(f'invalid `loginctl show-user` output:\n{output}')
-            yield SystemdUser(int(group[0]), group[1], group[2])
-
-    return show_users(list_users())
-
-
-class Request(Enum):
-    STATUS = 'status'
-    TOP = 'top'
-    REBOOT = 'reboot'
-    POWEROFF = 'poweroff'
-
-    def __str__(self):
-        return self.value
-
-    @staticmethod
-    def from_http_path(path):
-        if not path or path[0] != '/':
-            raise ValueError('HTTP path must start with a forward slash /')
-        return Request(path[1:])
-
-    def process(self):
-        if self is Request.STATUS:
-            return Status().complete()
-        if self is Request.TOP:
-            return Top().complete()
-        if self is Request.REBOOT:
-            return Reboot().complete()
-        if self is Request.POWEROFF:
-            return Poweroff().complete()
-        raise NotImplementedError(f'unknown request: {self}')
-
-
-def process_cgi_request():
-    params = cgi.FieldStorage()
-    what = params['what'].value
-    Request(what).process().write_as_cgi_script()
-
-
-def main():
-    process_cgi_request()
-
-
-if __name__ == '__main__':
-    main()