Extending the application

The base-images/db-mysql-fdw image is provided to build a Sparrow-compatible PostGIS image with the MySQL foreign data wrapper extension (for connecting with external MySQL databases). This functionality is not enabled by default because it adds ~700 Mb to the installed size of Sparrow and will not be necessary for most setups. However, it can be enabled with two steps: first, build the appropriate Docker image with sparrow build db-mysql-fdw. Then override the db portion of the docker-compose.yaml file with the new image definition: 1., create an overrides file (e.g. docker-compose.overrides.yaml with the following contents:

version: "3.4"
image: sparrowdata/db-mysql-fdw:1.0
  1. reference this overrides file with the SPARROW_COMPOSE_OVERRIDES environment variable in your config file, e.g.

This will update the Sparrow configuration transparently to use the new image in place of the default.

Once the image builds, you can run CREATE EXTENSION mysql_fdw in the sparrow database, or add this command to your SPARROW_INIT_SQL file.