Add fizzy-app-102 as a replica

The setup here is a bit rough while we settle some of the details, but
the gist of it is:

- Define accessories to run the primary/replica processes
- Add a web-replica role, which is similar to web but has the
  replication-side accessory
- Load the beamer extension on the app's primary tenanted database

Note that we aren't sending any traffic into the replica yet, but it
would be functional to do so. This stage is mainly about testing the
database replication.

Dockerfile

@@ -38,6 +38,10 @@ RUN bundle exec bootsnap precompile app/ lib/
 RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
 
 
+# Fetch beamer library
+FROM basecamp/beamer:latest AS beamer
+
+
 # Final stage for app image
 FROM base
 
@@ -49,6 +53,7 @@ RUN apt-get update -qq && \
 # Copy built artifacts: gems, application
 COPY --from=build /usr/local/bundle /usr/local/bundle
 COPY --from=build /rails /rails
+COPY --from=beamer /home/beamer/bin/beamer.so /rails/bin/lib/beamer.so
 
 # Run and own only the runtime files as a non-root user for security
 RUN useradd rails --create-home --shell /bin/bash && \