mailinabox/management/daemon.py

778 lines
26 KiB
Python
Executable File

#!/usr/local/lib/mailinabox/env/bin/python3
#
# The API can be accessed on the command line, e.g. use `curl` like so:
# curl --user $(</var/lib/mailinabox/api.key): http://localhost:10222/mail/users
#
# During development, you can start the Mail-in-a-Box control panel
# by running this script, e.g.:
#
# service mailinabox stop # stop the system process
# DEBUG=1 management/daemon.py
# service mailinabox start # when done debugging, start it up again
import os, os.path, re, json, time
import multiprocessing.pool
from functools import wraps
from flask import Flask, request, render_template, Response, send_from_directory, make_response
import auth, utils
from mailconfig import get_mail_users, get_mail_users_ex, get_admins, add_mail_user, set_mail_password, remove_mail_user
from mailconfig import get_mail_user_privileges, add_remove_mail_user_privilege
from mailconfig import get_mail_aliases, get_mail_aliases_ex, get_mail_domains, add_mail_alias, remove_mail_alias
from mfa import get_public_mfa_state, provision_totp, validate_totp_secret, enable_mfa, disable_mfa
env = utils.load_environment()
auth_service = auth.AuthService()
# We may deploy via a symbolic link, which confuses flask's template finding.
me = __file__
try:
me = os.readlink(__file__)
except OSError:
pass
# for generating CSRs we need a list of country codes
csr_country_codes = []
with open(os.path.join(os.path.dirname(me), "csr_country_codes.tsv")) as f:
for line in f:
if line.strip() == "" or line.startswith("#"): continue
code, name = line.strip().split("\t")[0:2]
csr_country_codes.append((code, name))
app = Flask(__name__, template_folder=os.path.abspath(os.path.join(os.path.dirname(me), "templates")))
# Decorator to protect views that require a user with 'admin' privileges.
def authorized_personnel_only(viewfunc):
@wraps(viewfunc)
def newview(*args, **kwargs):
# Authenticate the passed credentials, which is either the API key or a username:password pair
# and an optional X-Auth-Token token.
error = None
privs = []
try:
email, privs = auth_service.authenticate(request, env)
except ValueError as e:
# Write a line in the log recording the failed login, unless no authorization header
# was given which can happen on an initial request before a 403 response.
if "Authorization" in request.headers:
log_failed_login(request)
# Authentication failed.
error = str(e)
# Authorized to access an API view?
if "admin" in privs:
# Store the email address of the logged in user so it can be accessed
# from the API methods that affect the calling user.
request.user_email = email
request.user_privs = privs
# Call view func.
return viewfunc(*args, **kwargs)
if not error:
error = "You are not an administrator."
# Not authorized. Return a 401 (send auth) and a prompt to authorize by default.
status = 401
headers = {
'WWW-Authenticate': f'Basic realm="{auth_service.auth_realm}"',
'X-Reason': error,
}
if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
# Don't issue a 401 to an AJAX request because the user will
# be prompted for credentials, which is not helpful.
status = 403
headers = None
if request.headers.get('Accept') in {None, "", "*/*"}:
# Return plain text output.
return Response(error+"\n", status=status, mimetype='text/plain', headers=headers)
else:
# Return JSON output.
return Response(json.dumps({
"status": "error",
"reason": error,
})+"\n", status=status, mimetype='application/json', headers=headers)
return newview
@app.errorhandler(401)
def unauthorized(error):
return auth_service.make_unauthorized_response()
def json_response(data, status=200):
return Response(json.dumps(data, indent=2, sort_keys=True)+'\n', status=status, mimetype='application/json')
###################################
# Control Panel (unauthenticated views)
@app.route('/')
def index():
# Render the control panel. This route does not require user authentication
# so it must be safe!
no_users_exist = (len(get_mail_users(env)) == 0)
no_admins_exist = (len(get_admins(env)) == 0)
import boto3.s3
backup_s3_hosts = [(r, f"s3.{r}.amazonaws.com") for r in boto3.session.Session().get_available_regions('s3')]
return render_template('index.html',
hostname=env['PRIMARY_HOSTNAME'],
storage_root=env['STORAGE_ROOT'],
no_users_exist=no_users_exist,
no_admins_exist=no_admins_exist,
backup_s3_hosts=backup_s3_hosts,
csr_country_codes=csr_country_codes,
)
# Create a session key by checking the username/password in the Authorization header.
@app.route('/login', methods=["POST"])
def login():
# Is the caller authorized?
try:
email, privs = auth_service.authenticate(request, env, login_only=True)
except ValueError as e:
if "missing-totp-token" in str(e):
return json_response({
"status": "missing-totp-token",
"reason": str(e),
})
else:
# Log the failed login
log_failed_login(request)
return json_response({
"status": "invalid",
"reason": str(e),
})
# Return a new session for the user.
resp = {
"status": "ok",
"email": email,
"privileges": privs,
"api_key": auth_service.create_session_key(email, env, type='login'),
}
app.logger.info(f"New login session created for {email}")
# Return.
return json_response(resp)
@app.route('/logout', methods=["POST"])
def logout():
try:
email, _ = auth_service.authenticate(request, env, logout=True)
app.logger.info(f"{email} logged out")
except ValueError:
pass
finally:
return json_response({ "status": "ok" })
# MAIL
@app.route('/mail/users')
@authorized_personnel_only
def mail_users():
if request.args.get("format", "") == "json":
return json_response(get_mail_users_ex(env, with_archived=True))
else:
return "".join(x+"\n" for x in get_mail_users(env))
@app.route('/mail/users/add', methods=['POST'])
@authorized_personnel_only
def mail_users_add():
try:
return add_mail_user(request.form.get('email', ''), request.form.get('password', ''), request.form.get('privileges', ''), env)
except ValueError as e:
return (str(e), 400)
@app.route('/mail/users/password', methods=['POST'])
@authorized_personnel_only
def mail_users_password():
try:
return set_mail_password(request.form.get('email', ''), request.form.get('password', ''), env)
except ValueError as e:
return (str(e), 400)
@app.route('/mail/users/remove', methods=['POST'])
@authorized_personnel_only
def mail_users_remove():
return remove_mail_user(request.form.get('email', ''), env)
@app.route('/mail/users/privileges')
@authorized_personnel_only
def mail_user_privs():
privs = get_mail_user_privileges(request.args.get('email', ''), env)
if isinstance(privs, tuple): return privs # error
return "\n".join(privs)
@app.route('/mail/users/privileges/add', methods=['POST'])
@authorized_personnel_only
def mail_user_privs_add():
return add_remove_mail_user_privilege(request.form.get('email', ''), request.form.get('privilege', ''), "add", env)
@app.route('/mail/users/privileges/remove', methods=['POST'])
@authorized_personnel_only
def mail_user_privs_remove():
return add_remove_mail_user_privilege(request.form.get('email', ''), request.form.get('privilege', ''), "remove", env)
@app.route('/mail/aliases')
@authorized_personnel_only
def mail_aliases():
if request.args.get("format", "") == "json":
return json_response(get_mail_aliases_ex(env))
else:
return "".join(address+"\t"+receivers+"\t"+(senders or "")+"\n" for address, receivers, senders, auto in get_mail_aliases(env))
@app.route('/mail/aliases/add', methods=['POST'])
@authorized_personnel_only
def mail_aliases_add():
return add_mail_alias(
request.form.get('address', ''),
request.form.get('forwards_to', ''),
request.form.get('permitted_senders', ''),
env,
update_if_exists=(request.form.get('update_if_exists', '') == '1')
)
@app.route('/mail/aliases/remove', methods=['POST'])
@authorized_personnel_only
def mail_aliases_remove():
return remove_mail_alias(request.form.get('address', ''), env)
@app.route('/mail/domains')
@authorized_personnel_only
def mail_domains():
return "".join(x+"\n" for x in get_mail_domains(env))
# DNS
@app.route('/dns/zones')
@authorized_personnel_only
def dns_zones():
from dns_update import get_dns_zones
return json_response([z[0] for z in get_dns_zones(env)])
@app.route('/dns/update', methods=['POST'])
@authorized_personnel_only
def dns_update():
from dns_update import do_dns_update
try:
return do_dns_update(env, force=request.form.get('force', '') == '1')
except Exception as e:
return (str(e), 500)
@app.route('/dns/secondary-nameserver')
@authorized_personnel_only
def dns_get_secondary_nameserver():
from dns_update import get_custom_dns_config, get_secondary_dns
return json_response({ "hostnames": get_secondary_dns(get_custom_dns_config(env), mode=None) })
@app.route('/dns/secondary-nameserver', methods=['POST'])
@authorized_personnel_only
def dns_set_secondary_nameserver():
from dns_update import set_secondary_dns
try:
return set_secondary_dns([ns.strip() for ns in re.split(r"[, ]+", request.form.get('hostnames') or "") if ns.strip() != ""], env)
except ValueError as e:
return (str(e), 400)
@app.route('/dns/custom')
@authorized_personnel_only
def dns_get_records(qname=None, rtype=None):
# Get the current set of custom DNS records.
from dns_update import get_custom_dns_config, get_dns_zones
records = get_custom_dns_config(env, only_real_records=True)
# Filter per the arguments for the more complex GET routes below.
records = [r for r in records
if (not qname or r[0] == qname)
and (not rtype or r[1] == rtype) ]
# Make a better data structure.
records = [
{
"qname": r[0],
"rtype": r[1],
"value": r[2],
"sort-order": { },
} for r in records ]
# To help with grouping by zone in qname sorting, label each record with which zone it is in.
# There's an inconsistency in how we handle zones in get_dns_zones and in sort_domains, so
# do this first before sorting the domains within the zones.
zones = utils.sort_domains([z[0] for z in get_dns_zones(env)], env)
for r in records:
for z in zones:
if r["qname"] == z or r["qname"].endswith("." + z):
r["zone"] = z
break
# Add sorting information. The 'created' order follows the order in the YAML file on disk,
# which tracs the order entries were added in the control panel since we append to the end.
# The 'qname' sort order sorts by our standard domain name sort (by zone then by qname),
# then by rtype, and last by the original order in the YAML file (since sorting by value
# may not make sense, unless we parse IP addresses, for example).
for i, r in enumerate(records):
r["sort-order"]["created"] = i
domain_sort_order = utils.sort_domains([r["qname"] for r in records], env)
for i, r in enumerate(sorted(records, key = lambda r : (
zones.index(r["zone"]) if r.get("zone") else 0, # record is not within a zone managed by the box
domain_sort_order.index(r["qname"]),
r["rtype"]))):
r["sort-order"]["qname"] = i
# Return.
return json_response(records)
@app.route('/dns/custom/<qname>', methods=['GET', 'POST', 'PUT', 'DELETE'])
@app.route('/dns/custom/<qname>/<rtype>', methods=['GET', 'POST', 'PUT', 'DELETE'])
@authorized_personnel_only
def dns_set_record(qname, rtype="A"):
from dns_update import do_dns_update, set_custom_dns_record
try:
# Normalize.
rtype = rtype.upper()
# Read the record value from the request BODY, which must be
# ASCII-only. Not used with GET.
value = request.stream.read().decode("ascii", "ignore").strip()
if request.method == "GET":
# Get the existing records matching the qname and rtype.
return dns_get_records(qname, rtype)
elif request.method in {"POST", "PUT"}:
# There is a default value for A/AAAA records.
if rtype in {"A", "AAAA"} and value == "":
value = request.environ.get("HTTP_X_FORWARDED_FOR") # normally REMOTE_ADDR but we're behind nginx as a reverse proxy
# Cannot add empty records.
if value == '':
return ("No value for the record provided.", 400)
if request.method == "POST":
# Add a new record (in addition to any existing records
# for this qname-rtype pair).
action = "add"
elif request.method == "PUT":
# In REST, PUT is supposed to be idempotent, so we'll
# make this action set (replace all records for this
# qname-rtype pair) rather than add (add a new record).
action = "set"
elif request.method == "DELETE":
if value == '':
# Delete all records for this qname-type pair.
value = None
else:
# Delete just the qname-rtype-value record exactly.
pass
action = "remove"
if set_custom_dns_record(qname, rtype, value, action, env):
return do_dns_update(env) or "Something isn't right."
return "OK"
except ValueError as e:
return (str(e), 400)
@app.route('/dns/dump')
@authorized_personnel_only
def dns_get_dump():
from dns_update import build_recommended_dns
return json_response(build_recommended_dns(env))
@app.route('/dns/zonefile/<zone>')
@authorized_personnel_only
def dns_get_zonefile(zone):
from dns_update import get_dns_zonefile
return Response(get_dns_zonefile(zone, env), status=200, mimetype='text/plain')
# SSL
@app.route('/ssl/status')
@authorized_personnel_only
def ssl_get_status():
from ssl_certificates import get_certificates_to_provision
from web_update import get_web_domains_info, get_web_domains
# What domains can we provision certificates for? What unexpected problems do we have?
provision, cant_provision = get_certificates_to_provision(env, show_valid_certs=False)
# What's the current status of TLS certificates on all of the domain?
domains_status = get_web_domains_info(env)
domains_status = [
{
"domain": d["domain"],
"status": d["ssl_certificate"][0],
"text": d["ssl_certificate"][1] + ((" " + cant_provision[d["domain"]] if d["domain"] in cant_provision else ""))
} for d in domains_status ]
# Warn the user about domain names not hosted here because of other settings.
for domain in set(get_web_domains(env, exclude_dns_elsewhere=False)) - set(get_web_domains(env)):
domains_status.append({
"domain": domain,
"status": "not-applicable",
"text": "The domain's website is hosted elsewhere.",
})
return json_response({
"can_provision": utils.sort_domains(provision, env),
"status": domains_status,
})
@app.route('/ssl/csr/<domain>', methods=['POST'])
@authorized_personnel_only
def ssl_get_csr(domain):
from ssl_certificates import create_csr
ssl_private_key = os.path.join(os.path.join(env["STORAGE_ROOT"], 'ssl', 'ssl_private_key.pem'))
return create_csr(domain, ssl_private_key, request.form.get('countrycode', ''), env)
@app.route('/ssl/install', methods=['POST'])
@authorized_personnel_only
def ssl_install_cert():
from web_update import get_web_domains
from ssl_certificates import install_cert
domain = request.form.get('domain')
ssl_cert = request.form.get('cert')
ssl_chain = request.form.get('chain')
if domain not in get_web_domains(env):
return "Invalid domain name."
return install_cert(domain, ssl_cert, ssl_chain, env)
@app.route('/ssl/provision', methods=['POST'])
@authorized_personnel_only
def ssl_provision_certs():
from ssl_certificates import provision_certificates
requests = provision_certificates(env, limit_domains=None)
return json_response({ "requests": requests })
# multi-factor auth
@app.route('/mfa/status', methods=['POST'])
@authorized_personnel_only
def mfa_get_status():
# Anyone accessing this route is an admin, and we permit them to
# see the MFA status for any user if they submit a 'user' form
# field. But we don't include provisioning info since a user can
# only provision for themselves.
email = request.form.get('user', request.user_email) # user field if given, otherwise the user making the request
try:
resp = {
"enabled_mfa": get_public_mfa_state(email, env)
}
if email == request.user_email:
resp.update({
"new_mfa": {
"totp": provision_totp(email, env)
}
})
except ValueError as e:
return (str(e), 400)
return json_response(resp)
@app.route('/mfa/totp/enable', methods=['POST'])
@authorized_personnel_only
def totp_post_enable():
secret = request.form.get('secret')
token = request.form.get('token')
label = request.form.get('label')
if type(token) != str:
return ("Bad Input", 400)
try:
validate_totp_secret(secret)
enable_mfa(request.user_email, "totp", secret, token, label, env)
except ValueError as e:
return (str(e), 400)
return "OK"
@app.route('/mfa/disable', methods=['POST'])
@authorized_personnel_only
def totp_post_disable():
# Anyone accessing this route is an admin, and we permit them to
# disable the MFA status for any user if they submit a 'user' form
# field.
email = request.form.get('user', request.user_email) # user field if given, otherwise the user making the request
try:
result = disable_mfa(email, request.form.get('mfa-id') or None, env) # convert empty string to None
except ValueError as e:
return (str(e), 400)
if result: # success
return "OK"
else: # error
return ("Invalid user or MFA id.", 400)
# WEB
@app.route('/web/domains')
@authorized_personnel_only
def web_get_domains():
from web_update import get_web_domains_info
return json_response(get_web_domains_info(env))
@app.route('/web/update', methods=['POST'])
@authorized_personnel_only
def web_update():
from web_update import do_web_update
return do_web_update(env)
# System
@app.route('/system/version', methods=["GET"])
@authorized_personnel_only
def system_version():
from status_checks import what_version_is_this
try:
return what_version_is_this(env)
except Exception as e:
return (str(e), 500)
@app.route('/system/latest-upstream-version', methods=["POST"])
@authorized_personnel_only
def system_latest_upstream_version():
from status_checks import get_latest_miab_version
try:
return get_latest_miab_version()
except Exception as e:
return (str(e), 500)
@app.route('/system/status', methods=["POST"])
@authorized_personnel_only
def system_status():
from status_checks import run_checks
class WebOutput:
def __init__(self):
self.items = []
def add_heading(self, heading):
self.items.append({ "type": "heading", "text": heading, "extra": [] })
def print_ok(self, message):
self.items.append({ "type": "ok", "text": message, "extra": [] })
def print_error(self, message):
self.items.append({ "type": "error", "text": message, "extra": [] })
def print_warning(self, message):
self.items.append({ "type": "warning", "text": message, "extra": [] })
def print_line(self, message, monospace=False):
self.items[-1]["extra"].append({ "text": message, "monospace": monospace })
output = WebOutput()
# Create a temporary pool of processes for the status checks
with multiprocessing.pool.Pool(processes=5) as pool:
run_checks(False, env, output, pool)
pool.close()
pool.join()
return json_response(output.items)
@app.route('/system/updates')
@authorized_personnel_only
def show_updates():
from status_checks import list_apt_updates
return "".join(
"%s (%s)\n"
% (p["package"], p["version"])
for p in list_apt_updates())
@app.route('/system/update-packages', methods=["POST"])
@authorized_personnel_only
def do_updates():
utils.shell("check_call", ["/usr/bin/apt-get", "-qq", "update"])
return utils.shell("check_output", ["/usr/bin/apt-get", "-y", "upgrade"], env={
"DEBIAN_FRONTEND": "noninteractive"
})
@app.route('/system/reboot', methods=["GET"])
@authorized_personnel_only
def needs_reboot():
from status_checks import is_reboot_needed_due_to_package_installation
if is_reboot_needed_due_to_package_installation():
return json_response(True)
else:
return json_response(False)
@app.route('/system/reboot', methods=["POST"])
@authorized_personnel_only
def do_reboot():
# To keep the attack surface low, we don't allow a remote reboot if one isn't necessary.
from status_checks import is_reboot_needed_due_to_package_installation
if is_reboot_needed_due_to_package_installation():
return utils.shell("check_output", ["/sbin/shutdown", "-r", "now"], capture_stderr=True)
else:
return "No reboot is required, so it is not allowed."
@app.route('/system/backup/status')
@authorized_personnel_only
def backup_status():
from backup import backup_status
try:
return json_response(backup_status(env))
except Exception as e:
return json_response({ "error": str(e) })
@app.route('/system/backup/config', methods=["GET"])
@authorized_personnel_only
def backup_get_custom():
from backup import get_backup_config
return json_response(get_backup_config(env, for_ui=True))
@app.route('/system/backup/config', methods=["POST"])
@authorized_personnel_only
def backup_set_custom():
from backup import backup_set_custom
return json_response(backup_set_custom(env,
request.form.get('target', ''),
request.form.get('target_user', ''),
request.form.get('target_pass', ''),
request.form.get('min_age', '')
))
@app.route('/system/privacy', methods=["GET"])
@authorized_personnel_only
def privacy_status_get():
config = utils.load_settings(env)
return json_response(config.get("privacy", True))
@app.route('/system/privacy', methods=["POST"])
@authorized_personnel_only
def privacy_status_set():
config = utils.load_settings(env)
config["privacy"] = (request.form.get('value') == "private")
utils.write_settings(config, env)
return "OK"
# MUNIN
@app.route('/munin/')
@authorized_personnel_only
def munin_start():
# Munin pages, static images, and dynamically generated images are served
# outside of the AJAX API. We'll start with a 'start' API that sets a cookie
# that subsequent requests will read for authorization. (We don't use cookies
# for the API to avoid CSRF vulnerabilities.)
response = make_response("OK")
response.set_cookie("session", auth_service.create_session_key(request.user_email, env, type='cookie'),
max_age=60*30, secure=True, httponly=True, samesite="Strict") # 30 minute duration
return response
def check_request_cookie_for_admin_access():
session = auth_service.get_session(None, request.cookies.get("session", ""), "cookie", env)
if not session: return False
privs = get_mail_user_privileges(session["email"], env)
if not isinstance(privs, list): return False
if "admin" not in privs: return False
return True
def authorized_personnel_only_via_cookie(f):
@wraps(f)
def g(*args, **kwargs):
if not check_request_cookie_for_admin_access():
return Response("Unauthorized", status=403, mimetype='text/plain', headers={})
return f(*args, **kwargs)
return g
@app.route('/munin/<path:filename>')
@authorized_personnel_only_via_cookie
def munin_static_file(filename=""):
# Proxy the request to static files.
if filename == "": filename = "index.html"
return send_from_directory("/var/cache/munin/www", filename)
@app.route('/munin/cgi-graph/<path:filename>')
@authorized_personnel_only_via_cookie
def munin_cgi(filename):
""" Relay munin cgi dynazoom requests
/usr/lib/munin/cgi/munin-cgi-graph is a perl cgi script in the munin package
that is responsible for generating binary png images _and_ associated HTTP
headers based on parameters in the requesting URL. All output is written
to stdout which munin_cgi splits into response headers and binary response
data.
munin-cgi-graph reads environment variables to determine
what it should do. It expects a path to be in the env-var PATH_INFO, and a
querystring to be in the env-var QUERY_STRING.
munin-cgi-graph has several failure modes. Some write HTTP Status headers and
others return nonzero exit codes.
Situating munin_cgi between the user-agent and munin-cgi-graph enables keeping
the cgi script behind mailinabox's auth mechanisms and avoids additional
support infrastructure like spawn-fcgi.
"""
COMMAND = 'su munin --preserve-environment --shell=/bin/bash -c /usr/lib/munin/cgi/munin-cgi-graph'
# su changes user, we use the munin user here
# --preserve-environment retains the environment, which is where Popen's `env` data is
# --shell=/bin/bash ensures the shell used is bash
# -c "/usr/lib/munin/cgi/munin-cgi-graph" passes the command to run as munin
# "%s" is a placeholder for where the request's querystring will be added
if filename == "":
return ("a path must be specified", 404)
query_str = request.query_string.decode("utf-8", 'ignore')
env = {'PATH_INFO': '/%s/' % filename, 'REQUEST_METHOD': 'GET', 'QUERY_STRING': query_str}
code, binout = utils.shell('check_output',
COMMAND.split(" ", 5),
# Using a maxsplit of 5 keeps the last arguments together
env=env,
return_bytes=True,
trap=True)
if code != 0:
# nonzero returncode indicates error
app.logger.error("munin_cgi: munin-cgi-graph returned nonzero exit code, %s", code)
return ("error processing graph image", 500)
# /usr/lib/munin/cgi/munin-cgi-graph returns both headers and binary png when successful.
# A double-Windows-style-newline always indicates the end of HTTP headers.
headers, image_bytes = binout.split(b'\r\n\r\n', 1)
response = make_response(image_bytes)
for line in headers.splitlines():
name, value = line.decode("utf8").split(':', 1)
response.headers[name] = value
if 'Status' in response.headers and '404' in response.headers['Status']:
app.logger.warning("munin_cgi: munin-cgi-graph returned 404 status code. PATH_INFO=%s", env['PATH_INFO'])
return response
def log_failed_login(request):
# We need to figure out the ip to list in the message, all our calls are routed
# through nginx who will put the original ip in X-Forwarded-For.
# During setup we call the management interface directly to determine the user
# status. So we can't always use X-Forwarded-For because during setup that header
# will not be present.
if request.headers.getlist("X-Forwarded-For"):
ip = request.headers.getlist("X-Forwarded-For")[0]
else:
ip = request.remote_addr
# We need to add a timestamp to the log message, otherwise /dev/log will eat the "duplicate"
# message.
app.logger.warning( "Mail-in-a-Box Management Daemon: Failed login attempt from ip %s - timestamp %s" % (ip, time.time()))
# APP
if __name__ == '__main__':
if "DEBUG" in os.environ:
# Turn on Flask debugging.
app.debug = True
if not app.debug:
app.logger.addHandler(utils.create_syslog_handler())
#app.logger.info('API key: ' + auth_service.key)
# Start the application server. Listens on 127.0.0.1 (IPv4 only).
app.run(port=10222)