
PostgreSQL is an open-source, advanced Relational Database Management System (RDBMS) designed for managing various data tasks. It uses Structured Query Language (SQL) to handle data in both small and large applications, including analytical systems, GIS, healthcare apps, and dynamic web applications.
This article walks you through installing PostgreSQL on an Ubuntu 20.04 server, enabling the database server, and securing it for production use.
Prerequisites
Before you begin:
Have an Ubuntu 20.04 server.
Access the server using SSH as a non-root user with sudo privileges.
Install PostgreSQL
PostgreSQL is available in the default APT repositories on Ubuntu. Follow the steps below to install the PostgreSQL database server packages and enable the application to start at boot time.
Update the server package index.
console$ sudo apt update
Install the
postgresql-common
dependency package on your server.console$ sudo apt install -y postgresql-common -y
Run the following command to execute the PostgreSQL APT repository script.
console$ sudo /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh
Press Enter when prompted to add the new repository to your server sources.
This script will enable the PostgreSQL APT repository on apt.postgresql.org on your system. The distribution codename used will be noble-pgdg. Press Enter to continue, or Ctrl-C to abort.
Install the
postgresql
database server package.console$ sudo apt install -y postgresql
Start the PostgreSQL database server.
console$ sudo systemctl start postgresql
View the PostgreSQL system service status and verify that it's active.
console$ sudo systemctl status postgresql
Output:
● postgresql.service - PostgreSQL RDBMS Loaded: loaded (/usr/lib/systemd/system/postgresql.service; enabled; preset: enabled) Active: active (exited) since Mon 2024-05-27 16:09:21 UTC; 35s ago Process: 5601 ExecStart=/bin/true (code=exited, status=0/SUCCESS) Main PID: 5601 (code=exited, status=0/SUCCESS) CPU: 3ms
Secure the PostgreSQL Database Server
PostgreSQL operates using the default postgres
privileged database user account. Follow the steps below to enable password authentication and secure the database server, ensuring that only authorized users can access the databases.
Check your installed PostgreSQL version.
console$ psql --version
Output:
psql (PostgreSQL) 17.4 (Ubuntu 17.4-1.pgdg20.04+2)
Log in to the PostgreSQL database server using the
postgres
user account.console$ sudo -u postgres psql
Modify the default
postgres
user with a new strong password.sqlpostgres=# ALTER USER postgres WITH ENCRYPTED PASSWORD 'strong_password';
Create a new user
db_manager
with a new strong password.sqlpostgres=# CREATE USER db_manager ENCRYPTED PASSWORD 'strong_password';
Exit the PostgreSQL console.
sqlpostgres=# quit;
Run the following command to change the default
peer
value in thescram-sha-256
field in the main PostgreSQL configuration filepg_hba.conf
to enable password authentication on the server.console$ sudo sed -i '/^local/s/peer/scram-sha-256/' /etc/postgresql/17/main/pg_hba.conf
Replace
17
with your installed PostgreSQL version number if it's different.Restart the PostgreSQL server to apply the new configuration changes.
console$ sudo systemctl restart postgresql
Access the PostgreSQL Database Server
The psql
utility, pre-installed with the server package, allows you to access the PostgreSQL database console. You can also use compatible graphical tools for direct connection to the console. Follow the steps below to access your PostgreSQL database and create a new sample database for use with your non-privileged user.
Create a new sample PostgreSQL database
hospital
and grant thedb_manager
user ownership privileges to the database.console$ sudo -u postgres createdb hospital -O db_manager
When prompted, enter the Postgres user password you created earlier.
Log in to the PostgreSQL database as the user
db_manager
to test access to thehospital
database.console$ sudo -u postgres psql -U db_manager -d hospital
Enter the database user password when prompted and press Enter to access the database.
Create a new sample
doctors
table.sqlhospital=> CREATE TABLE doctors ( doctor_id SERIAL PRIMARY KEY, first_name VARCHAR(50), last_name VARCHAR(50), appointment_date DATE );
The above SQL statement creates a new table in the
hospital
database with the following columns:doctor_id
is aPRIMARY KEY
that uniquely identifies each doctor in thedoctors
table.first_name
andlast_name
store names in thedoctors
table.appointment_date
stores the doctor's appointment date with a patient in the hospital.SERIAL
generates a newdoctor_id
for each new record.
Insert sample data into the
doctors
table.sqlhospital=> INSERT INTO doctors ( first_name, last_name, appointment_date) VALUES ( 'Ben', 'Joe', '2024-11-15'), ( 'Carson', 'Smith', '2024-02-28'), ( 'Donald', 'James', '2024-04-10');
Query the
doctors
table to view all available records.sqlhospital=> SELECT * FROM doctors;
Output:
sqldoctor_id | first_name | last_name | appointment_date -----------+------------+-----------+------------------ 1 | Ben | Joe | 2024-11-15 2 | Carson | Smith | 2024-02-28 3 | Donald | James | 2024-04-10 (3 rows)
Exit the PostgreSQL console.
sqlhospital=> quit;
Conclusion
PostgreSQL is now installed on your Ubuntu 20.04 server. You've accessed the database using the psql
utility to create sample databases and tables. You can integrate PostgreSQL with your applications to securely manage database records. For more details, visit the official PostgreSQL documentation.
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