Files
python-teos/watchtower-plugin/watchtower.py
2020-05-05 15:19:31 +02:00

315 lines
13 KiB
Python
Executable File

#!/usr/bin/env python3
import os
import plyvel
from queue import Queue
from pyln.client import Plugin
from threading import Thread, Lock
from common.tools import compute_locator
from common.appointment import Appointment
from common.config_loader import ConfigLoader
from common.cryptographer import Cryptographer
from common.exceptions import InvalidParameter, SignatureError, EncryptionError
import arg_parser
from retrier import Retrier
from tower_info import TowerInfo
from towers_dbm import TowersDBM
from keys import generate_keys, load_keys
from exceptions import TowerConnectionError, TowerResponseError
from net.http import post_request, process_post_response, add_appointment
DATA_DIR = os.getenv("TOWERS_DATA_DIR", os.path.expanduser("~/.watchtower/"))
CONF_FILE_NAME = "watchtower.conf"
DEFAULT_CONF = {
"DEFAULT_PORT": {"value": 9814, "type": int},
"MAX_RETRIES": {"value": 30, "type": int},
"APPOINTMENTS_FOLDER_NAME": {"value": "appointment_receipts", "type": str, "path": True},
"TOWERS_DB": {"value": "towers", "type": str, "path": True},
"PRIVATE_KEY": {"value": "sk.der", "type": str, "path": True},
}
plugin = Plugin()
class WTClient:
def __init__(self, sk, user_id, config):
self.sk = sk
self.user_id = user_id
self.towers = {}
self.tmp_unreachable_towers = []
self.db_manager = TowersDBM(config.get("TOWERS_DB"), plugin)
self.retrier = Retrier(config.get("MAX_RETRIES"), Queue())
self.config = config
self.lock = Lock()
# Populate the towers dict with data from the db
for tower_id, tower_info in self.db_manager.load_all_tower_records().items():
self.towers[tower_id] = TowerInfo.from_dict(tower_info).get_summary()
Thread(target=self.retrier.manage_retry, args=[plugin], daemon=True).start()
def update_tower_state(self, tower_id, tower_update):
self.lock.acquire()
tower_info = TowerInfo.from_dict(self.db_manager.load_tower_record(tower_id))
if "status" in tower_update:
tower_info.status = tower_update.get("status")
if "appointment" in tower_update:
locator, signature = tower_update.get("appointment")
tower_info.appointments[locator] = signature
tower_info.available_slots = tower_update.get("available_slots")
if "pending_appointment" in tower_update:
data, action = tower_update.get("pending_appointment")
if action == "add":
tower_info.pending_appointments.append(list(data))
else:
tower_info.pending_appointments.remove(list(data))
if "invalid_appointment" in tower_update:
tower_info.invalid_appointments.append(list(tower_update.get("invalid_appointment")))
self.towers[tower_id] = tower_info.get_summary()
self.db_manager.store_tower_record(tower_id, tower_info)
self.lock.release()
@plugin.init()
def init(options, configuration, plugin):
try:
user_sk, user_id = generate_keys(DATA_DIR)
plugin.log(f"Generating a new key pair for the watchtower client. Keys stored at {DATA_DIR}")
except FileExistsError:
plugin.log("A key file for the watchtower client already exists. Loading it")
user_sk, user_id = load_keys(DATA_DIR)
plugin.log(f"Plugin watchtower client initialized. User id = {user_id}")
config_loader = ConfigLoader(DATA_DIR, CONF_FILE_NAME, DEFAULT_CONF, {})
try:
plugin.wt_client = WTClient(user_sk, user_id, config_loader.build_config())
except plyvel.IOError:
error = "Cannot load towers db. Resource temporarily unavailable"
plugin.log("Cannot load towers db. Resource temporarily unavailable")
raise IOError(error)
@plugin.method("registertower", desc="Register your public key (user id) with the tower.")
def register(plugin, tower_id, host=None, port=None):
"""
Registers the user to the tower.
Args:
plugin (:obj:`Plugin`): this plugin.
tower_id (:obj:`str`): the identifier of the tower to connect to (a compressed public key).
host (:obj:`str`): the ip or hostname to connect to, optional.
host (:obj:`int`): the port to connect to, optional.
Accepted tower_id formats:
- tower_id@host:port
- tower_id host port
- tower_id@host (will default port to DEFAULT_PORT)
- tower_id host (will default port to DEFAULT_PORT)
Returns:
:obj:`dict`: a dictionary containing the subscription data.
"""
try:
tower_id, tower_netaddr = arg_parser.parse_register_arguments(tower_id, host, port, plugin.wt_client.config)
# Defaulting to http hosts for now
if not tower_netaddr.startswith("http"):
tower_netaddr = "http://" + tower_netaddr
# Send request to the server.
register_endpoint = f"{tower_netaddr}/register"
data = {"public_key": plugin.wt_client.user_id}
plugin.log(f"Registering in the Eye of Satoshi (tower_id={tower_id})")
response = process_post_response(post_request(data, register_endpoint, tower_id))
plugin.log(f"Registration succeeded. Available slots: {response.get('available_slots')}")
# Save data
tower_info = TowerInfo(tower_netaddr, response.get("available_slots"))
plugin.wt_client.lock.acquire()
plugin.wt_client.towers[tower_id] = tower_info.get_summary()
plugin.wt_client.db_manager.store_tower_record(tower_id, tower_info)
plugin.wt_client.lock.release()
return response
except (InvalidParameter, TowerConnectionError, TowerResponseError) as e:
plugin.log(str(e), level="warn")
return e.to_json()
@plugin.method("getappointment", desc="Gets appointment data from the tower given the tower id and the locator.")
def get_appointment(plugin, tower_id, locator):
"""
Gets information about an appointment from the tower.
Args:
plugin (:obj:`Plugin`): this plugin.
tower_id (:obj:`str`): the identifier of the tower to query.
locator (:obj:`str`): the appointment locator.
Returns:
:obj:`dict`: a dictionary containing the appointment data.
"""
# FIXME: All responses from the tower should be signed.
try:
tower_id, locator = arg_parser.parse_get_appointment_arguments(tower_id, locator)
if tower_id not in plugin.wt_client.towers:
raise InvalidParameter("tower_id is not within the registered towers", tower_id=tower_id)
message = f"get appointment {locator}"
signature = Cryptographer.sign(message.encode(), plugin.wt_client.sk)
data = {"locator": locator, "signature": signature}
# Send request to the server.
tower_netaddr = plugin.wt_client.towers[tower_id].get("netaddr")
get_appointment_endpoint = f"{tower_netaddr}/get_appointment"
plugin.log(f"Requesting appointment from {tower_id}")
response = process_post_response(post_request(data, get_appointment_endpoint, tower_id))
return response
except (InvalidParameter, TowerConnectionError, TowerResponseError) as e:
plugin.log(str(e), level="warn")
return e.to_json()
@plugin.method("listtowers", desc="List all towers registered towers.")
def list_towers(plugin):
towers_info = {"towers": []}
for tower_id, info in plugin.wt_client.towers.items():
values = {k: v for k, v in info.items() if k != "pending_appointments"}
pending_appointments = [appointment.get("locator") for appointment, signature in info["pending_appointments"]]
invalid_appointments = [appointment.get("locator") for appointment, signature in info["invalid_appointments"]]
values["pending_appointments"] = pending_appointments
values["invalid_appointments"] = invalid_appointments
towers_info["towers"].append({"id": tower_id, **values})
return towers_info
@plugin.method("gettowerinfo", desc="List all towers registered towers.")
def get_tower_info(plugin, tower_id):
tower_info = TowerInfo.from_dict(plugin.wt_client.db_manager.load_tower_record(tower_id))
pending_appointments = [
{"appointment": appointment, "signature": signature}
for appointment, signature in tower_info.pending_appointments
]
invalid_appointments = [
{"appointment": appointment, "tower_signature": signature}
for appointment, signature in tower_info.invalid_appointments
]
tower_info.pending_appointments = pending_appointments
tower_info.invalid_appointments = invalid_appointments
return {"id": tower_id, **tower_info.to_dict()}
@plugin.method("retrytower", desc="Retry to send pending appointment to an unreachable tower.")
def retry_tower(plugin, tower_id):
response = None
plugin.wt_client.lock.acquire()
tower = plugin.wt_client.towers.get(tower_id)
if not tower:
response = {"error": f"{tower_id} is not a registered tower"}
if tower.get("status") not in ["unreachable", "subscription error"]:
response = {"error": f"{tower_id} is not unreachable. {tower.get('status')}"}
if not tower.get("pending_appointments"):
response = {"error": f"{tower_id} does not have pending appointments"}
if not response:
response = f"Retrying tower {tower_id}"
plugin.log(response)
plugin.wt_client.towers[tower_id]["status"] = "temporarily unreachable"
plugin.wt_client.retrier.temp_unreachable_towers.put(tower_id)
plugin.wt_client.lock.release()
return response
@plugin.hook("commitment_revocation")
def on_commitment_revocation(plugin, **kwargs):
try:
commitment_txid, penalty_tx = arg_parser.parse_add_appointment_arguments(kwargs)
appointment = Appointment(
locator=compute_locator(commitment_txid),
to_self_delay=20, # does not matter for now, any value 20-2^32-1 would do
encrypted_blob=Cryptographer.encrypt(penalty_tx, commitment_txid),
)
signature = Cryptographer.sign(appointment.serialize(), plugin.wt_client.sk)
except (InvalidParameter, EncryptionError, SignatureError) as e:
plugin.log(str(e), level="warn")
return {"result": "continue"}
# Send appointment to the towers.
# FIXME: sending the appointment to all registered towers atm. Some management would be nice.
for tower_id, tower in plugin.wt_client.towers.items():
tower_update = {}
if tower.get("status") == "misbehaving":
return {"result": "continue"}
try:
if tower.get("status") == "reachable":
tower_signature, available_slots = add_appointment(
plugin, tower_id, tower, appointment.to_dict(), signature
)
tower_update["appointment"] = (appointment.locator, tower_signature)
tower_update["available_slots"] = available_slots
else:
if tower.get("status") in ["temporarily unreachable", "unreachable"]:
plugin.log(f"{tower_id} is {tower.get('status')}. Adding {appointment.locator} to pending")
elif tower.get("status") == "subscription error":
plugin.log(f"There is a subscription issue with {tower_id}. Adding appointment to pending")
tower_update["pending_appointment"] = (appointment.to_dict(), signature), "add"
except SignatureError as e:
tower_update["status"] = "misbehaving"
tower_update["invalid_appointment"] = (appointment.to_dict(), e.kwargs.get("signature"))
except TowerConnectionError:
# All TowerConnectionError are transitory. Connections are tried on register so URLs cannot be malformed.
# Flag appointment for retry
tower_update["status"] = "temporarily unreachable"
plugin.log(f"Adding {appointment.locator} to pending")
tower_update["pending_appointment"] = (appointment.to_dict(), signature), "add"
tower_update["retry"] = True
except TowerResponseError as e:
tower_update["status"] = e.kwargs.get("status")
if tower_update["status"] in ["temporarily unreachable", "subscription_error"]:
plugin.log(f"Adding {appointment.locator} to pending")
tower_update["pending_appointment"] = (appointment.to_dict(), signature), "add"
if tower_update["status"] == "temporarily unreachable":
tower_update["retry"] = True
finally:
# Update memory and TowersDB
plugin.wt_client.update_tower_state(tower_id, tower_update)
if tower_update.get("retry"):
plugin.wt_client.retrier.temp_unreachable_towers.put(tower_id)
return {"result": "continue"}
plugin.run()