Docker Images

Docker Images for Avatica

Docker is a popular piece of software that enables other software to run “anywhere”. In the context of Avatica, we can use Docker to enable a run-anywhere Avatica server. These Docker containers can be used to easily create a server for the development of custom Avatica clients or encapsulating database access for testing software that uses Avatica.

Base “avatica-server” Docker Image

Avatica provides a number of Docker containers. Each of these images is based on a “parent” “avatica-server” Docker image.

This Docker image has no bindings to a specific database (it has not database-specific JDBC driver included). It only contains a Java runtime and the Avatica Standalone Server jar (which contains all the necessary dependencies of the Avatica server). This docker image is not directly useful for end users; it is useful for those who want to use Avatica with a database of their choosing.

This Docker image is deployed to the Apache Docker Hub account and is updated for each release of Avatica.

Database-specific Docker Images

To make the lives of end-users who want to use a specific database easier, some Docker images are provided for some common databases. The current databases include:

• HyperSQL (2.3.1)
• MySQL (Client 5.1.41, supports MySQL server 4.1, 5.0, 5.1, 5.5, 5.6, 5.7)
• PostgreSQL (Client 42.0.0, supports PostgreSQL servers >=8.3)

These images are not deployed as the licensing on each database driver is varied. Please understand and accept the license of each before using in any software project.

Each of these images include a build.sh script which will build the docker image using the latest avatica-server Docker image. The resulting Docker image will be named according to the following format: avatica-<database>-server. For example, avatica-hsqldb-server, avatica-mysql-server, and avatica-postgresql-server.

Additionally, Docker Compose configuration files for the above databases (sans HyperSQL) are provided which configure the database’s standard Docker image and then connect Avatica to that Docker container. For example, the PostgreSQL docker-compose configuration file will start an instance of PostgreSQL and an instance of the Avatica server, each in their own container, exposing an Avatica server configured against a “real” PostgreSQL database.

All of the Dockerfile and docker-compose.yml files are conveniently provided in an archive for each release. Here is the layout for release 1.25.0:

avatica-docker-1.25.0/
avatica-docker-1.25.0/hypersql/
avatica-docker-1.25.0/mysql/
avatica-docker-1.25.0/postgresql/
avatica-docker-1.25.0/Dockerfile
avatica-docker-1.25.0/hypersql/build.sh
avatica-docker-1.25.0/hypersql/Dockerfile
avatica-docker-1.25.0/mysql/build.sh
avatica-docker-1.25.0/mysql/docker-compose.yml
avatica-docker-1.25.0/mysql/Dockerfile
avatica-docker-1.25.0/postgresql/build.sh
avatica-docker-1.25.0/postgresql/docker-compose.yml
avatica-docker-1.25.0/postgresql/Dockerfile

Running

Each of the provided database-specific Docker images set an ENTRYPOINT which encapsulate most of the Java command. The following options are available to specify:

Usage: <main class> [options]
  Options:
    -h, -help, --help
       Print the help message
       Default: false
    -p, --port
       Port the server should bind
       Default: 0
    -s, --serialization
       Serialization method to use
       Default: PROTOBUF
       Possible Values: [JSON, PROTOBUF]
  * -u, --url
       JDBC driver url for the server

For example, to connect to a MySQL server, the following could be used:

$ ./avatica-docker-*/mysql/build.sh
$ docker run --rm -it avatica-mysql-server \
    -u jdbc:mysql://<fqdn>:3306/my_database

To debug these docker images, the ENTRYPOINT can be overriden to launch a shell

$ docker run --rm --entrypoint='' -it avatica-mysql-server /bin/sh

Running Docker containers for custom databases

The provided avatica-server Docker image is designed to be generally reusable for developers that want to expose a database of their choosing. A custom Dockerfile can be created by copying what the avatica-mysql-server or avatica-postgresql-server do, but this is also achievable via the Docker volumes.

For example, consider we have a JAR with a JDBC driver for our database on our local machine /home/user/my-database-jars/my-database-jdbc-1.0.jar. We can run the following command to launch a custom Avatica server against our database with this JDBC driver.

$ docker run --rm -p 8765:8765 \
    -v /home/user/my-database-jars/:/my-database-jars --entrypoint="" -it avatica-server \
    /usr/bin/java -cp "/home/avatica/classpath/*:/my-database-jars/*" \
    org.apache.calcite.avatica.standalone.StandaloneServer -p 8765 \
    -u "jdbc:my_jdbc_url"

This command does the following:

• Exposes the internal port 8765 on the local machine as 8765
• Maps the local directory “home/user/my-database-jars” to the Docker container at “/my-database-jars” using the Docker volumes feature
• Adds that mapped directory to the Java classpath
• Sets the correct JDBC URL for the database

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