Use Liquibase with PostgreSQL on AWS RDS

PostgreSQL on AWS RDS allows users to deploy, manage, and scale your PostgreSQL database within the cloud. Learn how to set up Liquibase with PostgreSQL on AWS RDS below.

Verified Versions

  • 16
  • 15
  • 14
  • 13
  • 12

Deprecated Versions

  • Amazon AWS RDS for PostgreSQL 11 is deprecated as of November 9, 2023.

    • Liquibase support for this version ends on February 7, 2024.
    • Other versions remain supported.

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

PostgreSQL on AWS RDS

  1. Ensure your PostgreSQL database is configured.
    1. Check the connection by using any standard SQL client application, including the psql command line utility that is part of a PostgreSQL installation, and running the following:

      • Linux, macOS, or Unix

      • psql \
        --host=<DB instance endpoint> \
        --port=<port> \
        --username=<master username> \
        --password \
        --dbname=<database name>
      • Windows

      • psql ^
        --host=<DB instance endpoint> ^
        --port=<port> ^
        --username=<master username> ^
        --password ^
        --dbname=<database name>
    2. Note: If this is the first time you are connecting to your DB instance, you can try using the default database name postgres for the --dbname option.

      Tip: The alternative way is to connect with pgAdmin, which is an open-source administration and development tool for PostgreSQL.

    3. You can find the connection information in the AWS Management Console:

      1. Sign in to the AWS Management Console and open the Amazon RDS console.
      2. In the upper-right corner of the console, choose the AWS Region of your DB instance.
      3. Find the host and port for your DB Instance:
        • Select Databases and choose the needed PostgreSQL DB instance to display the instance details.
        • Select Connectivity & security. You will see all information under Endpoint & Port.
    4. Note: To find the connection information using the AWS CLI, call the describe-db-instances command: aws rds describe-db-instances. Alternatively, you can use the Amazon RDS API DescribeDBInstances operation.

  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:
  3. url: jdbc:postgresql://<instance_host>:<instance_port>/<database_name>?user=userName&password=password

    Example: url: jdbc:postgresql://myinstance.123456789012.us-east-1.rds.amazonaws.com:5432/postgresql?user=user&password=password

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

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.

  2. --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>
  3. Navigate to your project folder in the CLI and run the Liquibase status command to see whether the connection is successful:
  4. 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.
  5. Inspect the deployment SQL with the update-sql command:
  6. 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.

  7. Then execute these changes to your database with the update command:
  8. 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.
  9. 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!

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