Welcome to Supabase Postgres contributing guide

Adding a new extension

Extensions can either be built from source or installed through a debian package. In general, you want to add the installation commands for your extension to the Dockerfile following the steps below.

Create a build stage named after your extension.
Add build args that specify the extension's release version.
If your extension is published as a package, download it to /tmp/<name>.deb using the ADD command.
If you need to build the extensions from source, use checkinstall to create a /tmp/<name>.deb package.
Copy your extension's package from build stage to extensions stage.

Here's a minimal example:

ARG pg_graphql_release=1.1.0

####################
# 19-pg_graphql.yml
####################
FROM base as pg_graphql
# Download package archive
ARG pg_graphql_release
ADD "https://github.com/supabase/pg_graphql/releases/download/v${pg_graphql_release}/pg_graphql-v${pg_graphql_release}-pg${postgresql_major}-${TARGETARCH}-linux-gnu.deb" \
    /tmp/pg_graphql.deb

####################
# Collect extension packages
####################
FROM scratch as extensions
COPY --from=pg_graphql /tmp/*.deb /tmp/

Using this process maximises the effectiveness of Docker layer caching, which significantly speeds up our CI builds.

Testing an extension

Extensions can be tested automatically using pgTAP. Start by creating a new file in migrations/tests/extensions. For example:

BEGIN;
create extension if not exists wrappers with schema "extensions";
ROLLBACK;

This test will be run as part of CI to check that your extension can be enabled successfully from the final Docker image.