power-mailinabox/management/utils.py

import os.path

# DO NOT import non-standard modules. This module is imported by
# migrate.py which runs on fresh machines before anything is installed
# besides Python.

# THE ENVIRONMENT FILE AT /etc/mailinabox.conf


def load_environment():
	# Load settings from /etc/mailinabox.conf.
	return load_env_vars_from_file("/etc/mailinabox.conf")


def load_env_vars_from_file(fn):
	# Load settings from a KEY=VALUE file.
	import collections
	env = collections.OrderedDict()
	for line in open(fn):
		env.setdefault(*line.strip().split("=", 1))
	return env


def save_environment(env):
	with open("/etc/mailinabox.conf", "w") as f:
		for k, v in env.items():
			f.write("%s=%s\n" % (k, v))


# THE SETTINGS FILE AT STORAGE_ROOT/settings.yaml.


def write_settings(config, env):
	import rtyaml
	fn = os.path.join(env['STORAGE_ROOT'], 'settings.yaml')
	with open(fn, "w") as f:
		f.write(rtyaml.dump(config))


def load_settings(env):
	import rtyaml
	fn = os.path.join(env['STORAGE_ROOT'], 'settings.yaml')
	try:
		config = rtyaml.load(open(fn, "r"))
		if not isinstance(config, dict):
			raise ValueError()  # caught below
		return config
	except:
		return {}


# UTILITIES


def safe_domain_name(name):
	# Sanitize a domain name so it is safe to use as a file name on disk.
	import urllib.parse
	return urllib.parse.quote(name, safe='')


def sort_domains(domain_names, env):
	# Put domain names in a nice sorted order.

	# The nice order will group domain names by DNS zone, i.e. the top-most
	# domain name that we serve that ecompasses a set of subdomains. Map
	# each of the domain names to the zone that contains them. Walk the domains
	# from shortest to longest since zones are always shorter than their
	# subdomains.
	zones = {}
	for domain in sorted(domain_names, key=lambda d: len(d)):
		for z in zones.values():
			if domain.endswith("." + z):
				# We found a parent domain already in the list.
				zones[domain] = z
				break
		else:
			# 'break' did not occur: there is no parent domain, so it is its
			# own zone.
			zones[domain] = domain

	# Sort the zones.
	zone_domains = sorted(
		zones.values(),
		key=lambda d: (
			# PRIMARY_HOSTNAME or the zone that contains it is always first.
			not (d == env['PRIMARY_HOSTNAME'] or env['PRIMARY_HOSTNAME'].
				endswith("." + d)),

			# Then just dumb lexicographically.
			d,
		))

	# Now sort the domain names that fall within each zone.
	domain_names = sorted(
		domain_names,
		key=lambda d: (
			# First by zone.
			zone_domains.index(zones[d]),

			# PRIMARY_HOSTNAME is always first within the zone that contains it.
			d != env['PRIMARY_HOSTNAME'],

			# Followed by any of its subdomains.
			not d.endswith("." + env['PRIMARY_HOSTNAME']),

			# Then in right-to-left lexicographic order of the .-separated parts of the name.
			list(reversed(d.split("."))),
		))

	return domain_names


def sort_email_addresses(email_addresses, env):
	email_addresses = set(email_addresses)
	domains = set(
		email.split("@", 1)[1] for email in email_addresses if "@" in email)
	ret = []
	for domain in sort_domains(domains, env):
		domain_emails = set(email for email in email_addresses
							if email.endswith("@" + domain))
		ret.extend(sorted(domain_emails))
		email_addresses -= domain_emails
	ret.extend(sorted(email_addresses))  # whatever is left
	return ret


def shell(method,
		cmd_args,
		env={},
		capture_stderr=False,
		return_bytes=False,
		trap=False,
		input=None):
	# A safe way to execute processes.
	# Some processes like apt-get require being given a sane PATH.
	import subprocess

	env.update({"PATH": "/sbin:/bin:/usr/sbin:/usr/bin"})
	kwargs = {
		'env': env,
		'stderr': None if not capture_stderr else subprocess.STDOUT,
	}
	if method == "check_output" and input is not None:
		kwargs['input'] = input

	if not trap:
		ret = getattr(subprocess, method)(cmd_args, **kwargs)
	else:
		try:
			ret = getattr(subprocess, method)(cmd_args, **kwargs)
			code = 0
		except subprocess.CalledProcessError as e:
			ret = e.output
			code = e.returncode
	if not return_bytes and isinstance(ret, bytes):
		ret = ret.decode("utf8")
	if not trap:
		return ret
	else:
		return code, ret


def create_syslog_handler():
	import logging.handlers
	handler = logging.handlers.SysLogHandler(address='/dev/log')
	handler.setLevel(logging.WARNING)
	return handler


def du(path):
	# Computes the size of all files in the path, like the `du` command.
	# Based on http://stackoverflow.com/a/17936789. Takes into account
	# soft and hard links.
	total_size = 0
	seen = set()
	for dirpath, dirnames, filenames in os.walk(path):
		for f in filenames:
			fp = os.path.join(dirpath, f)
			try:
				stat = os.lstat(fp)
			except OSError:
				continue
			if stat.st_ino in seen:
				continue
			seen.add(stat.st_ino)
			total_size += stat.st_size
	return total_size


def wait_for_service(port, public, env, timeout):
	# Block until a service on a given port (bound privately or publicly)
	# is taking connections, with a maximum timeout.
	import socket
	import time
	start = time.perf_counter()
	while True:
		s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
		s.settimeout(timeout / 3)
		try:
			s.connect(("127.0.0.1" if not public else env['PUBLIC_IP'], port))
			return True
		except OSError:
			if time.perf_counter() > start + timeout:
				return False
		time.sleep(min(timeout / 4, 1))


def fix_boto():
	# Google Compute Engine instances install some Python-2-only boto plugins that
	# conflict with boto running under Python 3. Disable boto's default configuration
	# file prior to importing boto so that GCE's plugin is not loaded:
	import os
	os.environ["BOTO_CONFIG"] = "/etc/boto3.cfg"


def get_php_version():
	# Gets the version of PHP installed in the system.
	return shell("check_output", ["/usr/bin/php", "-v"])[4:7]

def get_os_code():
	# Massive mess incoming
	dist = shell("check_output", ["/usr/bin/lsb_release", "-is"]).strip()
	version = shell("check_output", ["/usr/bin/lsb_release", "-rs"]).strip()

	if dist == "Debian":
		if version == "10":
			return "Debian10"
		elif version == "11":
			return "Debian11"
	elif dist == "Ubuntu":
		if version == "20.04":
			return "Ubuntu2004"
		elif version == "22.04":
			return "Ubuntu2204"

	return None


if __name__ == "__main__":
	from web_update import get_web_domains
	env = load_environment()
	domains = get_web_domains(env)
	for domain in domains:
		print(domain)