Connect Liquibase with PostgreSQL on AWS RDS

If you're running Liquibase using the Maven plugin using mvn liquibase:update installing the extension with Maven ensures the right files are available and everything works together automatically. You can manage these extensions by adding them as dependencies in your project’s pom.xml file. When configured this way, Maven automatically downloads the specified JAR files from Maven Central during the build process.

1. Ensure your PostgreSQL database is configured

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>

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.

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

2. You can find the connection information by signing into the AWS Management Console and navigating to the Amazon RDS console.

In the upper-right corner of the console, choose the AWS Region of your DB instance. 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.

3. 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://<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

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

1. Create a text file called changelog (.sql, .yaml, .json, or .xml) 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. Navigate to your project folder in the CLI and run the Liquibase status command to see whether the connection is successful:

liquibase status

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

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

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. Verify that the database contains your test_table and the DATABASECHANGELOG, and DATABASECHANGELOGLOCK tables.