Add support for postgres

Dockerfile

@@ -1,15 +1,15 @@
 FROM python:3.9-buster
 
-COPY cryptostore.py /cryptostore.py
-
 RUN apt install gcc git
 
 RUN pip install --no-cache-dir cython
 RUN pip install --no-cache-dir cryptofeed
 RUN pip install --no-cache-dir aioredis
 RUN pip install --no-cache-dir pymongo[srv]
 RUN pip install --no-cache-dir motor
+RUN pip install --no-cache-dir asyncpg
 
+COPY cryptostore.py /cryptostore.py
 
 CMD ["/cryptostore.py"]
 ENTRYPOINT ["python"]

cryptostore.py

@@ -13,6 +13,7 @@
 from cryptofeed.backends.redis import BookRedis, TradeRedis, TickerRedis, FundingRedis, CandlesRedis, OpenInterestRedis, LiquidationsRedis
 from cryptofeed.backends.redis import BookStream, TradeStream, TickerStream, FundingStream, CandlesStream, OpenInterestStream, LiquidationsStream
 from cryptofeed.backends.mongo import BookMongo, TradeMongo, TickerMongo, FundingMongo, CandlesMongo, OpenInterestMongo, LiquidationsMongo
+from cryptofeed.backends.postgres import BookPostgres, TradePostgres, TickerPostgres, FundingPostgres, CandlesPostgres, OpenInterestPostgres, LiquidationsPostgres
 
 
 async def tty(obj, receipt_ts):
@@ -52,6 +53,8 @@ def load_config() -> Feed:
         port = int(port)
     candle_interval = os.environ.get('CANDLE_INTERVAL', '1m')
     database = os.environ.get('DATABASE')
+    user = os.environ.get('USER')
+    password = os.environ.get('PASSWORD')
 
     cbs = None
     if backend == 'REDIS' or backend == 'REDISSTREAM':
@@ -76,6 +79,17 @@ def load_config() -> Feed:
             OPEN_INTEREST: OpenInterestMongo(database, **kwargs),
             LIQUIDATIONS: LiquidationsMongo(database, **kwargs)
         }
+    elif backend == 'POSTGRES':
+        kwargs = {'db': database, 'host': host, 'port': port if port else 5432, 'user': user, 'pw': password}
+        cbs = {
+            L2_BOOK: BookPostgres(snapshot_interval=snap_interval, snapshots_only=snap_only, **kwargs),
+            TRADES: TradePostgres(**kwargs),
+            TICKER: TickerPostgres(**kwargs),
+            FUNDING: FundingPostgres(**kwargs),
+            CANDLES: CandlesPostgres(**kwargs),
+            OPEN_INTEREST: OpenInterestPostgres(**kwargs),
+            LIQUIDATIONS: LiquidationsPostgres(**kwargs)
+        }
     elif backend == 'TTY':
         cbs = {
             L2_BOOK: tty,