我刚刚使用aws-lambda在Zappa上部署了Django应用，但出现错误。我不知道是否必须安装Postgres，因为我认为它是从requirements.txt中自动安装的。
OperationalError at /admin/login/ could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
Request Method: POST
Request URL: https://tmzgl5al3h.execute-api.ap-south-1.amazonaws.com/dev/admin/login/?next=%2Fdev%2Fadmin%2F
Django Version: 2.1.4
Exception Type: OperationalError
Exception Value: could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
Exception Location: /var/task/psycopg2/__init__.py in connect, line 130
Python Executable: /var/lang/bin/python3.6
Python Version: 3.6.1
Python Path: ['/var/task', '/opt/python/lib/python3.6/site-packages', '/opt/python', '/var/runtime', '/var/runtime/awslambda', '/var/lang/lib/python36.zip', '/var/lang/lib/python3.6', '/var/lang/lib/python3.6/lib-dynload', '/var/lang/lib/python3.6/site-packages', '/opt/python/lib/python3.6/site-packages', '/opt/python', '/var/task']