How to configure PostgreSQL 12.9 to allow remote connections

Huanjing ：

Ubuntu 20.04.3-live-server
Postgresql 12.9

Problem description ：

Postgresql 12.9 How to configure to allow remote connections

Solution ：

1. modify postgresql.conf The configuration file

vim /etc/postgresql/12/main/postgresql.conf

listen_addresses = '*'

2. edit pg_hba.conf The configuration file

vim /etc/postgresql/12/main/pg_hba.conf

#ipv4 local connetions
host  all  all 0.0.0.0/0 md5

MD5 Indicates that password verification is required , Also optional trust, No password required

3. Restart the database service
service postgresql restart

Check the status
service postgresql status

● postgresql.service - PostgreSQL RDBMS
     Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled)
     Active: active (exited) since Tue 2022-02-15 14:43:32 CST; 3s ago
    Process: 1255 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
   Main PID: 1255 (code=exited, status=0/SUCCESS)

4. Local connection test