/liquibase-postgres-docker

Docker for applying liquibase changes against PostgreSQL databases

Primary LanguageShellMIT LicenseMIT

liquibase-postgres-docker

A lightweight Docker for running Liquibase with PostgreSQL databases

DockerHub: liquibase-postgres - GitHub: liquibase-postgres-docker

Usage

Using your own derived Dockerfile

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.

Using the image directly with a mounted docker volume

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

Environment Variables and liquibase.properties

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