Install PostgreSQL on Ubuntu 18.04 Bionic Beaver

Objective

The objective is to Install PostgreSQL server or client on Ubuntu 18.04 Bionic Beaver

Operating System and Software Versions

• Operating System: - Ubuntu 18.04 Bionic Beaver
• Software: - PostgreSQL Server 10

Requirements

Privileged access to your Ubuntu System as root or via sudo command is required.

Difficulty

EASY

Conventions

• # - requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
• $ - requires given linux commands to be executed as a regular non-privileged user

Instructions

Install PostreSQL Client on Ubuntu

In case that you only need to connect to a remote PostreSQL server you only need to install PostgreSQL client on your local Ubuntu host. To do so execute:

$ sudo apt install postgresql-client

Once the installation of PostreSQl client is completed you can use psql command to connect to your remote PostreSQL server. For example the following linux command will connect to PostgreSQL server via hostname postresql-ubuntu as user postgres:

$ psql -h postresql-ubuntu -U postgres
psql (10.2 (Ubuntu 10.2-1))
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

See below on how to configure PostreSQL server to accept remote client connections.

Install PostreSQL Server on Ubuntu

In this section we will be installing PostgreSQL server on Ubuntu 18.04 Linux. The installation is as simple as:

$ sudo apt install postgresql

Once the PostreSQL installation is finished confirm that it is up and running as expected by checking for its listening socket on port number 5432:

$ ss -nlt
State       Recv-Q Send-Q Local Address:Port               Peer Address:Port
LISTEN      0      128       0.0.0.0:22                    0.0.0.0:*    
LISTEN      0      5       127.0.0.1:631                   0.0.0.0:*      
LISTEN      0      128     127.0.0.1:5432                  0.0.0.0:*   
LISTEN      0      128          [::]:22                       [::]:*   
LISTEN      0      5           [::1]:631                      [::]:*    

The PostgreSQL server will start after reboot. To manipulate this default behavior you can either disable or enable the PostreSQL start after reboot by:

$ sudo systemctl disable postgresql
OR
$ sudo systemctl enable postgresql

By default the PostgreSQL server will listen only on a local loop-back interface 127.0.0.1. If you need to configure your PostreSQL server to listen on all networks you will need to configure its main configuration file /etc/postgresql/10/main/postgresql.conf:

$ sudo nano /etc/postgresql/10/main/postgresql.conf

and add the following line somewhere to the CONNECTIONS AND AUTHENTICATION section:

listen_addresses = '*'

Once the configuration is completed restart PostreSQL server:

$ sudo service postgresql restart

The PostreSQL server should be now listening on socket 0.0.0.0:5432. You can confirm this by executing the ss command:

$ ss -nlt
State       Recv-Q Send-Q Local Address:Port               Peer Address:Port
LISTEN      0      128       0.0.0.0:22                    0.0.0.0:*    
LISTEN      0      5       127.0.0.1:631                   0.0.0.0:*      
LISTEN      0      128     0.0.0.0:5432                  0.0.0.0:*   
LISTEN      0      128          [::]:22                       [::]:*   
LISTEN      0      5           [::1]:631                      [::]:*    

Next, to accept connections from a remote PostreSQL client to all databases and all users add the following line to /etc/postgresql/10/main/pg_hba.conf

host    all          all            0.0.0.0/0  trust

Failing to do so may result in the following error message:

psql: FATAL:  no pg_hba.conf entry for host "postresql-client", user "postgres", database "postgres", SSL on
FATAL:  no pg_hba.conf entry for host "postresql-client", user "postgres", database "postgres", SSL off

Lastly, if you have UFW firewall enabled you can open the PostreSQL's port 5432 to any TCP incoming traffic by executing the below command:

$ sudo ufw allow from any to any port 5432 proto tcp
Rule added
Rule added (v6)

If you wish to make your firewall rules more strict visit our How to Open/Allow incoming firewall port guide for more information.