Fix merging of networks in compose config files for Docker Compose 24+

Makefile

@@ -470,6 +470,10 @@ run-shell: cmd=/bin/bash
 run-shell:
 	${DOCKER_COMPOSE_UP_PULL_CMD} run ${run_args} --entrypoint ${cmd} ${service}
 
+# show result of merging .yml docker compose config files
+docker-compose-config:
+	${DOCKER_COMPOSE_UP_PULL_CMD} config
+
 docker-compose-create-superuser:
 	${DOCKER_COMPOSE_CMD} exec app ./manage.py shell -c "from django.contrib.auth.models import User; User.objects.create_superuser('admin', 'admin@example.com', 'admin')"
 

docker/docker-compose-integration-tests.yml

@@ -189,9 +189,10 @@ networks:
     internal: false
     driver: bridge
 
-  public-internet:
+  public-internet: !override
     # make public network internal as well to run tests isolated from the internet
     internal: true
+
     # required to enable IPv6 on Docker Desktop runtime
     enable_ipv6: true
     driver: bridge

documentation/Docker-development-environment.md

@@ -343,6 +343,12 @@ It is also possible to enter the container used for the tests and run pytest dir
 
 For more information about how to invoke the test command see: [Integration Tests#tips-and-tricks](https://github.com/internetstandards/Internet.nl/blob/docker/documentation/Docker-integration-tests.md#tips-and-tricks)
 
+### Docker compose configuration files
+
+Newer versions of Docker Compose may have different ways of processing configuration files or the way they are merged. To see what the final configuration file looks like after merging for example `docker-compose.yml` and `docker-compose-intergration-test.yml` for the `test` environment run:
+
+    make docker-compose-config env=test
+
 ## Metrics (grafana/prometheus)
 
 The development environment includes the same metrics collection as used on the production environment. It consists of a Prometheus metrics server with various exporters and a Grafana frontend. To view metrics and graphs visit: `http://localhost:8080/grafana/` with user and password being `test`.