complement: init postgres DB directly inside the target image

changelog.d/13819.misc

@@ -0,0 +1 @@
+complement: init postgres DB directly inside the target image instead of the base postgres image to fix building using Buildah.

docker/complement/Dockerfile

@@ -17,26 +17,24 @@ ARG SYNAPSE_VERSION=latest
 # the same debian version as Synapse's docker image (so the versions of the
 # shared libraries match).
 
-FROM postgres:13-bullseye AS postgres_base
- # initialise the database cluster in /var/lib/postgresql
- RUN gosu postgres initdb --locale=C --encoding=UTF-8 --auth-host password
-
- # Configure a password and create a database for Synapse
- RUN echo "ALTER USER postgres PASSWORD 'somesecret'" | gosu postgres postgres --single
- RUN echo "CREATE DATABASE synapse" | gosu postgres postgres --single
-
 # now build the final image, based on the Synapse image.
 
 FROM matrixdotorg/synapse-workers:$SYNAPSE_VERSION
  # copy the postgres installation over from the image we built above
  RUN adduser --system --uid 999 postgres --home /var/lib/postgresql
- COPY --from=postgres_base /var/lib/postgresql /var/lib/postgresql
- COPY --from=postgres_base /usr/lib/postgresql /usr/lib/postgresql
- COPY --from=postgres_base /usr/share/postgresql /usr/share/postgresql
+ COPY --from=postgres:13-bullseye /usr/lib/postgresql /usr/lib/postgresql
+ COPY --from=postgres:13-bullseye /usr/share/postgresql /usr/share/postgresql
  RUN mkdir /var/run/postgresql && chown postgres /var/run/postgresql
  ENV PATH="${PATH}:/usr/lib/postgresql/13/bin"
  ENV PGDATA=/var/lib/postgresql/data
 
+ # initialise the database cluster in /var/lib/postgresql
+ RUN gosu postgres initdb --locale=C --encoding=UTF-8 --auth-host password
+
+ # Configure a password and create a database for Synapse
+ RUN echo "ALTER USER postgres PASSWORD 'somesecret'" | gosu postgres postgres --single
+ RUN echo "CREATE DATABASE synapse" | gosu postgres postgres --single
+
  # Extend the shared homeserver config to disable rate-limiting,
  # set Complement's static shared secret, enable registration, amongst other
  # tweaks to get Synapse ready for testing.