feat: add Postgres Failover Slots extension to images (#57)

Add the pg-failover-slots extension released by EnterpriseDB
under the PostgreSQL License to the default container images
for all supported Postgres versions.

URL: https://github.com/EnterpriseDB/pg_failover_slots

Closes #56

Signed-off-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>
Signed-off-by: Niccolò Fei <niccolo.fei@enterprisedb.com>
Co-authored-by: Niccolò Fei <niccolo.fei@enterprisedb.com>

Debian/Dockerfile.template

@@ -28,11 +28,13 @@ LABEL org.opencontainers.image.description="This Docker image contains PostgreSQ
 
 COPY requirements.txt /
 
-# Install pgaudit
+# Install additional extensions
 RUN set -xe; \
 	apt-get update; \
 	apt-get install -y --no-install-recommends \
-	    "postgresql-${PG_MAJOR}-pgaudit" ;\
+		"postgresql-${PG_MAJOR}-pgaudit" \
+		"postgresql-${PG_MAJOR}-pg-failover-slots" \
+	; \
 	rm -fr /tmp/* ; \
 	rm -rf /var/lib/apt/lists/*;
 

README.md

@@ -11,6 +11,7 @@ by adding the following software:
 
 - Barman Cloud
 - PGAudit
+- Postgres Failover Slots
 
 Barman Cloud is distributed by EnterpriseDB under the
 [GNU GPL 3 License](https://github.com/EnterpriseDB/barman/blob/master/LICENSE).
@@ -18,6 +19,9 @@ Barman Cloud is distributed by EnterpriseDB under the
 PGAudit is distributed under the
 [PostgreSQL License](https://github.com/pgaudit/pgaudit/blob/master/LICENSE).
 
+Postgres Failover Slots is distributed by EnterpriseDB under the
+[PostgreSQL License](https://github.com/EnterpriseDB/pg_failover_slots/blob/master/LICENSE).
+
 Images are available via
 [GitHub Container Registry](https://github.com/cloudnative-pg/postgres-containers/pkgs/container/postgresql).