A lightweight Docker for running Liquibase with PostgreSQL databases
DockerHub: liquibase-postgres - GitHub: liquibase-postgres-docker
You can use this image by creating your own Dockerfile which inherits using a FROM line:
FROM kilna/liquibase-postgres
ENV LIQUIBASE_HOST=database.server
ENV LIQUIBASE_DATABASE=dbname
ENV LIQUIBASE_USERNAME=user
ENV LIQUIBASE_PASSWORD=pass
COPY changelog.xml /workspace
Make sure to create an appropriate changelog.xml in the same directory as your Dockerfile.
Then you can build your derived Dockerfile to an image tagged 'changelog-image':
$ docker build --tag changelog-image .
Any time you make changes to the example project, you'll need to re-run the docker build command above, or you can using docker volumes as described below to sync local filesystem changes into the container. To run liquibase using the new image you can:
$ docker run changelog-image liquibase updateTestingRollback
Since the working directory within the container is /workspace, and since the entrypoint generates a a liquibase.properties file using the provided environment variables, it will know to look for changelog.xml by default and apply the change. See the environment variables below to change this behavior.
If you'd like to apply a changelog to a PostgreSQL database without deriving your own container, run the contiainer appropriate to your database like so... where /local/path/to/changelog/ is the directory where a valid changelog.xml exists:
$ docker run -e LIQUIBASE_HOST=database.server -e LIQUIBASE_USERNAME=user -e LIQUIBASE_PASSWORD=pass \
-e LIQUIBASE_DATABASE=dbname -v /local/path/to/changelog/:/workspace/ kilna/liquibase-postgres \
liquibase updateTestingRollback
This docker image has a working Liquibase executable in the path, and an entrypoint which auto-generates a liquibase.properties file.
In order to create the liquibase.properties file, it uses the follow environment variables when the image is started with 'docker run':
| Environment Variable | Purpose | Default |
|---|---|---|
| LIQUIBASE_HOST | Database host to connect to | db |
| LIQUIBASE_PORT | Database port to connect to | 5432 |
| LIQUIBASE_DATABASE | Database name to connect to | liquibase |
| LIQUIBASE_USERNAME | Username to connect to database as | liquibase |
| LIQUIBASE_PASSWORD | Password for username | liquibase |
| LIQUIBASE_CHANGELOG | Default changelog filename to use | changelog.xml |
| LIQUIBASE_LOGLEVEL | Log level as defined by Liquibase Valid values: debug, info, warning, severe, off |
info |
| LIQUIBASE_CLASSPATH | JDBC driver filename | /opt/jdbc/postgres-jdbc.jar |
| LIQUIBASE_DRIVER | JDBC object path | org.postgresql.Driver |
| LIQUIBASE_URL | JDBC URL for connection | jdbc:postgres://${HOST}:${PORT}/${DATABASE} |
| LIQUIBASE_DEBUG | If set to 'yes', when docker run is executed, will show the values of all LIQUIBASE_* environment variables and describes any substitutions performed on liquibase.properties | unset |
The generated liquibase.properties file is loaded into the default working dir /workspace (which is also shared as a docker volume). The /workspace/liquibase.properties file will have any variables substituted each time a 'docker run' command is performed... so you can load your own /workspace/liquibase.properties file and put ${HOST} in it, and it will be replaced with the LIQUIBASE_HOST environment variable.
If you want to see what the contents of the generated liquibase.properties file are, you can:
$ docker run image-name cat liquibase.properties