Use Liquibase with Azure Database for PostgreSQL

Azure SQL Database is a cloud based, object-relational database system that is compatible with Liquibase.

This guide covers how to setup Liquibase with Azure Database for PostgeSQL.

For more information, see Azure Database for MySQL Flexible Server and Azure Database for PostgreSQL Single Server

Verified database versions

Flexible Server:

• 16
• 15
• 13

Single Server:

• 11

Prerequisites

1. Introduction to Liquibase: Dive into Liquibase concepts.
2. Install Liquibase: Download Liquibase on your machine.
3. Ensure Java is installed: Liquibase requires Java to run. If you used the Liquibase Installer, Java is included automatically. Otherwise, you must install Java manually.
4. Get Started with Liquibase: Learn how to use Liquibase with an example database.
5. Design Your Liquibase Project: Create a new Liquibase project folder and organize your changelogs.
6. How to Apply Your Liquibase Pro License Key: If you use Liquibase Pro, activate your license.

Install drivers

CLI users

To use Liquibase and PostgreSQL, you need the JDBC driver JAR file (Maven download).

The latest version of Liquibase has a pre-installed driver for this database in the liquibase/internal/lib directory, so you don't need to install it yourself.

Maven users

To use Liquibase with Maven, you must instead include the driver JAR(s) as a dependency in your pom.xml file. Using this information, Maven automatically downloads the driver JAR from Maven Central when you build your project.

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.6.0</version>
</dependency>

Also, you can use the Liquibase PostgreSQL Extension JAR file, which is the vacuum extension that adds an additional changelog tag or command to support vacuuming.

Configure connection

1. Ensure your PostgreSQL database is configured. Check the status by running the pg_isready command. For more information about the options you can specify when running the command, see the pg_isready webpage.
2. Specify the database URL in the liquibase.properties file (defaults file), along with other properties you want to set a default value for. Liquibase does not parse the URL. You can either specify the full database connection string or specify the URL using your database's standard connection format:

url: jdbc:postgresql://${AZ_DATABASE_SERVER_NAME}.postgres.database.azure.com

Tip: To apply a Liquibase Pro key to your project, add the following property to the Liquibase properties file: licenseKey: <paste code here>

Note: If you use the connection pooling manager PG Bouncer, you must specify the connection port 5432.

Flexible Server via Service Principal Name

If you use Azure Flexible Server for PostgreSQL and want to authenticate using Service Principal Name (SPN) in your automation pipeline, follow these steps to connect to Liquibase:

1. Create an automation script that requests these parameters from the user:
• CLIENT_ID (username, example: 7ca151a7-cb01-4580-be03-0408df979c8f)
• CLIENT_SECRET (password)
• AZURE_TENANT_ID (the Active Directory tenant GUID to authenticate; a constant in your environment)
2. Run the following commands in automation:

az login -u "$CLIENT_ID" -p "$CLIENT_SECRET" -t "$AZURE_TENANT_ID" --service-principal
az account show
SPN=$(az ad sp show --id "$CLIENT_ID" | jq -r '.appDisplayName')
AAD_ACCESS_TOKEN=$(az account get-access-token --resource https://ossrdbms-aad.database.windows.net | jq -r '.accessToken')

3. Specify the following Liquibase parameters as environment variables:

export LIQUIBASE_COMMAND_URL="jdbc:postgresql://<database_server_name>.postgres.database.azure.com/postgres?sslmode=require"

export LIQUIBASE_COMMAND_USERNAME=$SPN

export LIQUIBASE_COMMAND_PASSWORD=$AAD_ACCESS_TOKEN

For more information, see the following guides:

• Integrate Azure Database for PostgreSQL with Service Connector
• Connect Azure Database for PostgreSQL - Flexible Server with the private access connectivity method
• Quickstart: Use Java and JDBC with Azure Database for PostgreSQL

Test connection

1. Create a text file called changelog (.xml, .sql, .yaml, or .json) in your project directory and add a changeset.

   If you already created a changelog using the init project command, you can use that instead of creating a new file. When adding onto an existing changelog, be sure to only add the changeset and to not duplicate the changelog header.

• SQL example
• YAML example
• JSON example
• XML example

--liquibase formatted sql

--changeset your.name:1
CREATE TABLE test_table (test_id INT NOT NULL, test_column INT, PRIMARY KEY (test_id))

Tip: Formatted SQL changelogs generated from Liquibase versions before 4.2.0 might cause issues because of the lack of space after a double dash ( -- ). To fix this, add a space after the double dash. For example: -- liquibase formatted sql instead of --liquibase formatted sql and -- changeset myname:create-table instead of --changeset myname:create-table.

databaseChangeLog:
   - changeSet:
       id: 1
       author: your.name
       changes:
       - createTable:
           tableName: test_table
           columns:
           - column:
               name: test_id
               type: INT
               constraints:
                   primaryKey:  true
                   nullable:  false
           - column:
               name: test_column
               type: INT

{
  "databaseChangeLog": [
    {
      "changeSet": {
        "id": "1",
        "author": "your.name",
        "changes": [
          {
            "createTable": {
              "tableName": "test_table",
              "columns": [
                {
                  "column": {
                    "name": "test_id",
                    "type": "INT",
                    "constraints": {
                      "primaryKey": true,
                      "nullable": false
                    }
                  }
                },
                {
                  "column": {
                    "name": "test_column",
                    "type": "INT"
                  }
                }
              ]
            }
          }
        ]
      }
    }
  ]
}

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:pro="http://www.liquibase.org/xml/ns/pro"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
        http://www.liquibase.org/xml/ns/dbchangelog-ext
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
        http://www.liquibase.org/xml/ns/pro
        http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd">

    <changeSet id="1" author="your.name">
        <createTable tableName="test_table">
            <column name="test_id" type="int">
                <constraints primaryKey="true" nullable="false" />
            </column>
            <column name="test_column" type="int"/>
        </createTable>
    </changeSet>

</databaseChangeLog>

2. Navigate to your project folder in the CLI and run the Liquibase status command to see whether the connection is successful:

liquibase status --username=test --password=test --changelog-file=<changelog.xml>

Note: You can specify arguments in the CLI or keep them in the Liquibase properties file.

If your connection is successful, you'll see a message like this:

4 changesets have not been applied to <your_connection_url>
Liquibase command 'status' was executed successfully.

3. Inspect the deployment SQL with the update-sql command:

liquibase update-sql --changelog-file=<changelog.xml>

If the SQL that Liquibase generates isn't what you expect, you should review your changelog file and make any necessary adjustments.

4. Then execute these changes to your database with the update command:

liquibase update --changelog-file=<changelog.xml>

If your update is successful, Liquibase runs each changeset and displays a summary message ending with:

Liquibase: Update has been successful.
Liquibase command 'update' was executed successfully.

5. From a database UI tool, ensure that your database contains the test_table object you added along with the DATABASECHANGELOG table and DATABASECHANGELOGLOCK table.

Now you're ready to start making deployments with Liquibase!

Troubleshooting

If you use Azure Database with PostgreSQL and the connection pooling manager PG Bouncer, you may receive this error when you try to use Liquibase:

prepared statement ... does not exist

If you receive this error, it is because you are using the connection port 6432, which is typical for PG Bouncer. However, for Liquibase's prepared statements to work, the connection pooling mode must be set to session. However, using Azure with PostgreSQL does not support the session value. Therefore, Liquibase's prepared statements may fail, causing the execution to fail.

To resolve this error, set your connection port to 5432.

Related links

• Getting Started: Using Liquibase with Azure Postgres