[kmaau@rocky ~]$ mkdir ${HOME}/liquibase-demo
[kmaau@rocky ~]$ ls -ld ${HOME}/liquibase-demo
drwxr-xr-x. 2 kmaau kmaau 6 Aug  3 20:50 /home/kmaau/liquibase-demo
[kmaau@rocky ~]$ cd ${HOME}/liquibase-demo

[kmaau@rocky liquibase-demo]$ vi docker-compose.yml
::
::

[kmaau@rocky liquibase-demo]$ cat docker-compose.yml
[[blue:services:]]
[[blue:  postgres:]]
[[blue:    image: postgres:18]]
[[blue:    container_name: postgres-demo]]
[[blue:    environment:]]
[[blue:      POSTGRES_DB: appdb]]
[[blue:      POSTGRES_USER: appuser]]
[[blue:      POSTGRES_PASSWORD: password]]
[[blue:    ports:]]
[[blue:      - "5432:5432"]]

#
# spin up PostgreSQL in docker:
#
kmaau@rocky liquibase-demo]$ docker compose up --detach
[+] up 17/18
 ⠦ Image postgres:18 [[[green:⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿]]] 150.2MB / 159.8MB Pulling 
[[green:✔]] Image postgres:18              [[green:Pulled]]                                                             10.0s
[[green:✔]] Network liquibase-demo_default [[green:Created]]                                                             0.1s
 ⠦ Container postgres-demo       [[green:Started]]                                                             0.6s

kmaau@rocky liquibase-demo]$ docker image list
                                          i Info →   U  In Use
IMAGE         ID             DISK USAGE   CONTENT SIZE   EXTRA
postgres:18   3a82e1f56c8f        644MB          168MB    U   

[kmaau@rocky liquibase-demo]$ docker compose ps --all
NAME          IMAGE       COMMAND                SERVICE  CREATED       STATUS       PORTS
postgres-demo postgres:18 "docker-entrypoint.s…" postgres 7 seconds ago Up 6 seconds 0.0.0.0:5432->5432/tcp, 
                                                                                     [::]:5432->5432/tcp
#
# connect to the PostgreSQL:
#
[kmaau@rocky liquibase-demo]$ psql --host=localhost --username=appuser --dbname=appdb
Password for user appuser: [[yellow:password]]
psql (18.4)
Type "help" for help.
appdb=# SELECT version();
                                                      version                                                    
--------------------------------------------------------------------------------------------------------------------
 PostgreSQL 18.4 (Debian 18.4-1.pgdg13+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 14.2.0-19) 14.2.0, 64-bit
(1 row)

appdb=# \quit

#
# configure Liquibase:
#
[kmaau@rocky liquibase-demo]$ mkdir db
[kmaau@rocky liquibase-demo]$ ls -ld db
drwxr-xr-x. 2 kmaau kmaau 6 Aug  4 03:03 db
[kmaau@rocky liquibase-demo]$ cd db

[kmaau@rocky db]$ tree .
.
├── changelog.xml
├── liquibase.properties
└── postgresql-42.7.13.jar
0 directories, 3 files

[kmaau@rocky db]$ cat liquibase.properties 
[[blue:changeLogFile=changelog.xml]]
[[blue:url=jdbc:postgresql://localhost:5432/appdb]]
[[blue:username=appuser]]
[[blue:password=password]]
[[blue:classpath=postgresql-42.7.13.jar]]

[kmaau@rocky db]$ cat changelog.xml 
[[blue:<?xml version="1.0" encoding="UTF-8"?>]]
[[blue:<databaseChangeLog]]
[[blue:    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"]]
[[blue:    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"]]
[[blue:    xsi:schemaLocation="]]
[[blue:        http://www.liquibase.org/xml/ns/dbchangelog]]
[[blue:        https://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd">]]
[[blue:]]
[[blue:    <changeSet id="001" author="kmaau">]]
[[blue:        <createTable tableName="users">]]
[[blue:            <column name="id" type="BIGINT">]]
[[blue:                <constraints primaryKey="true" nullable="false"/>]]
[[blue:            </column>]]
[[blue:            <column name="username" type="VARCHAR(100)"/>]]
[[blue:        </createTable>]]
[[blue:    </changeSet>]]
[[blue:]]
[[blue:</databaseChangeLog>]]

#
# create first schema:
#
[kmaau@rocky db]$ liquibase validate
Starting Liquibase at 03:23:47 using Java 25.0.4 (version 5.0.3 #10665 built at 2026-05-13 17:55+0000)
Liquibase Version: 5.0.3
No validation errors found.
Liquibase command 'validate' was executed successfully.

[kmaau@rocky db]$ liquibase update
Starting Liquibase at 03:25:15 using Java 25.0.4 (version 5.0.3 #10665 built at 2026-05-13 17:55+0000)
Liquibase Version: 5.0.3
Running Changeset: changelog.xml::001::kmaau
UPDATE SUMMARY
Run:                          1
Previously run:               0
Filtered out:                 0
-------------------------------
Total change sets:            1
Liquibase: Update has been successful. Rows affected: 0
Liquibase command 'update' was executed successfully.

[kmaau@rocky db]$ psql --host=localhost --username=appuser --dbname=appdb --command "\dt+;"
Password for user appuser: [[yellow:password]]
                                              List of tables
 Schema |         Name          | Type  |  Owner  | Persistence | Access method |    Size    | Description 
--------+-----------------------+-------+---------+-------------+---------------+------------+-------------
 public | databasechangelog     | table | appuser | permanent   | heap          | 16 kB      | 
 public | databasechangeloglock | table | appuser | permanent   | heap          | 8192 bytes | 
 public | users                 | table | appuser | permanent   | heap          | 0 bytes    | 
(3 rows)

[kmaau@rocky db]$ docker compose down
[+] down 2/2
 [[green:✔]] Container postgres-demo        [[green:Removed]]                                                            0.3s
 [[green:✔]] Network liquibase-demo_default [[green:Removed]]

kmaau@rocky ~]$ cd ${HOME}
[kmaau@rocky ~]$ rm -rf ${HOME}/liquibase-demo