Postgresql

PostgreSQL is a well known opensource database that scales well and is easy to use.

Installation

PostgreSQL 17 is the latest version since v3.21.

To install PostgreSQL 17,

# apk add postgresql17 postgresql17-contrib postgresql17-openrc

# rc-update add postgresql

# rc-service postgresql start

This will start the postgresql server and perform some initial configuration. It will also create a system user called postgres.

Older versions of PostgreSQL 16, PostgreSQL 15 and PostgreSQL 14 are still available as of v3.22 and can be installed using the same commands as above except for replacing the version number in the appropriate package names. For example, postgresql17 is to be replaced by postgresql16, postgresql15 and postgresql14 for PostgreSQL 16, PostgreSQL 15 and PostgreSQL 14 respectively.

Configuration

Login as the postgres user and start psql to create a new user and database:

su postgres

psql

create user user with encrypted password 'password';

create database database;

grant all privileges on database database to user;

Network access

By default only local access is allowed to PostgreSQL. To allow other networked services to access the database we need to configure PostgreSQL to allow external connections.

In this example, we are using PostgreSQL v16, so substitute below for your specific version. Edit the /etc/postgresql16/postgresql.conf file using nano or any other <editor> /etc/postgresql16/postgresql.conf

Find the line that starts with

#listen_addresses = 'localhost'

Uncomment it and change it to the following:

listen_addresses = '*'

If you want it to listen on a specific ip you can change * to 192.168.1.2/24. Save the file and change the next config file.

Modify the /etc/postgresql16/pg_hba.conf file using nano or any other <editor> /etc/postgresql16/pg_hba.conf

Look for the line:

host    all             all             127.0.0.1/32            md5

And change it to:

host all all 0.0.0.0/0 md5

This line allows connections from any IP address and requires a password for authentication (md5).

Restart the server to allow incoming connections from other hosts.

rc-service postgresql restart

Allow the port through the firewall. For UFW firewall type:

ufw allow 5432

This is a basic configuration. You can configure the PostgreSQL server to only allow certain networks or IP's to connect, but that's beyond the scope of this documentation.

Switching between PostgreSQL versions

On Alpine Linux, you can use the command `pg_versions` to switch between PostgreSQL versions. This is very helpful when upgrading the version you are using.

Upgrading PostgreSQL

Please follow along with this guide and adjust the version you are moving from and the version you are upgrading to.

There's also this.

See also

• Guide for Upgrading PostgreSQL
• older postgresql upgrade guide