Implement stoploss for kraken

freqtrade/exchange/kraken.py

@@ -4,7 +4,8 @@ from typing import Dict
 
 import ccxt
 
-from freqtrade.exceptions import OperationalException, TemporaryError
+from freqtrade.exceptions import (DependencyException, InvalidOrderException,
+                                  OperationalException, TemporaryError)
 from freqtrade.exchange import Exchange
 from freqtrade.exchange.exchange import retrier
 
@@ -15,6 +16,7 @@ class Kraken(Exchange):
 
     _params: Dict = {"trading_agreement": "agree"}
     _ft_has: Dict = {
+        "stoploss_on_exchange": True,
         "trades_pagination": "id",
         "trades_pagination_arg": "since",
     }
@@ -48,3 +50,44 @@ class Kraken(Exchange):
                 f'Could not get balance due to {e.__class__.__name__}. Message: {e}') from e
         except ccxt.BaseError as e:
             raise OperationalException(e) from e
+
+    def stoploss(self, pair: str, amount: float, stop_price: float, order_types: Dict) -> Dict:
+        """
+        Creates a stoploss market order.
+        Stoploss market orders is the only stoploss type supported by kraken.
+        """
+
+        ordertype = "stop-loss"
+
+        stop_price = self.price_to_precision(pair, stop_price)
+
+        if self._config['dry_run']:
+            dry_order = self.dry_run_order(
+                pair, ordertype, "sell", amount, stop_price)
+            return dry_order
+
+        try:
+            params = self._params.copy()
+
+            amount = self.amount_to_precision(pair, amount)
+
+            order = self._api.create_order(symbol=pair, type=ordertype, side='sell',
+                                           amount=amount, price=stop_price, params=params)
+            logger.info('stoploss order added for %s. '
+                        'stop price: %s.', pair, stop_price)
+            return order
+        except ccxt.InsufficientFunds as e:
+            raise DependencyException(
+                f'Insufficient funds to create {ordertype} sell order on market {pair}.'
+                f'Tried to create stoploss with amount {amount} at stoploss {stop_price}. '
+                f'Message: {e}') from e
+        except ccxt.InvalidOrder as e:
+            raise InvalidOrderException(
+                f'Could not create {ordertype} sell order on market {pair}. '
+                f'Tried to create stoploss with amount {amount} at stoploss {stop_price}. '
+                f'Message: {e}') from e
+        except (ccxt.NetworkError, ccxt.ExchangeError) as e:
+            raise TemporaryError(
+                f'Could not place sell order due to {e.__class__.__name__}. Message: {e}') from e
+        except ccxt.BaseError as e:
+            raise OperationalException(e) from e