我创建了一个amazon ec2 ubuntu实例并在其中安装了postgres但无法连接它。我启用了安全组HTTP（80），Postgres（5432）和ssh（22）。
在pgadmin中连接后会抛出错误 服务器不听
The server doesn't accept connections: the connection library reports
could not connect to server: Connection refused (0x0000274D/10061) Is the server running on host "54.172.***.***" and accepting TCP/IP connections on port 5432?