feat(compose): services listen on their configured port, publishing is commented out with a random host port

README.md

@@ -4,6 +4,8 @@ Copier template for a Python backend, either as a `backend/` part next to other
 
 Ships `backend/docker-compose.yml` with root-relative paths and profiles per service, `docker-compose.override.yml.example` (published ports and the `caddy` network aliases, copied by `make env`), a `Makefile` with `fmt`, `check`, `build` and service-specific targets, `.env.example` and `CLAUDE.md`. Applied on top of the `infra` template, `layout: parts` or `layout: single` respectively.
 
+`DB__HOST`/`DB__PORT` and `REDIS__HOST`/`REDIS__PORT` say where the service really is. The bundled container takes the host as its network alias and listens on the port, the override publishes it on the machine. For an external database, point them at it and leave its profile out of `COMPOSE_PROFILES`.
+
 ```sh
 copier copy --trust -d project_name="My Thing" <this-repo> <dest>
 copier update -a .copier/backend.yml

template/{{ part_dir }}/Makefile.jinja

@@ -49,8 +49,15 @@ post-deploy:
 	fi
 {% endif %}{% if layout == 'root' %}
 env:
-	@test -f .env || cp .env.example .env
-	@test -f docker-compose.override.yml || cp docker-compose.override.yml.example docker-compose.override.yml
+	@fresh=; test -f .env || { cp .env.example .env; fresh=1; }; \
+	if ! test -f docker-compose.override.yml; then \
+		cp docker-compose.override.yml.example docker-compose.override.yml; \
+		for port in $$(sed -n 's/.*127\.0\.0\.1:\([0-9]*\):.*/\1/p' docker-compose.override.yml | sort -u); do \
+			random=$$((20000 + $$(od -An -N2 -tu2 /dev/urandom) % 40000)); \
+			sed "s/127\.0\.0\.1:$$port:/127.0.0.1:$$random:/" docker-compose.override.yml > docker-compose.override.yml.tmp && mv docker-compose.override.yml.tmp docker-compose.override.yml; \
+			test -z "$$fresh" || { sed "s|localhost:$$port/|localhost:$$random/|" .env > .env.tmp && mv .env.tmp .env; }; \
+		done; \
+	fi
 
 recreate:
 	$(COMPOSE) up -d --force-recreate

template/{{ part_dir }}/docker-compose.override.yml.example.jinja

@@ -11,15 +11,17 @@ services:{% if not entries %} {}{% endif %}
       caddy:
         aliases:
           - {{ dash }}-api
+#    ports:
+#      - "127.0.0.1:8080:${API__PORT}"
 {% elif entry == 'mongodb' %}  mongodb:
-    ports:
-      - "127.0.0.1:${DB__PORT:-27017}:${DB__PORT:-27017}"
+#    ports:
+#      - "127.0.0.1:27017:${DB__PORT}"
 {% elif entry == 'postgres' %}  postgres:
-    ports:
-      - "127.0.0.1:${DB__PORT:-5432}:5432"
+#    ports:
+#      - "127.0.0.1:5432:${DB__PORT}"
 {% elif entry == 'redis' %}  redis:
-    ports:
-      - "127.0.0.1:${REDIS__PORT:-6379}:6379"
+#    ports:
+#      - "127.0.0.1:6379:${REDIS__PORT}"
 {% endif %}{% if not loop.last %}
 {% endif %}{% endfor %}{% if 'api' in backend_services %}
 networks:

template/{{ part_dir }}/docker-compose.yml.jinja

@@ -50,18 +50,18 @@ services:
     environment:
       MONGO_INITDB_ROOT_USERNAME: ${DB__USER}
       MONGO_INITDB_ROOT_PASSWORD: ${DB__PASSWORD}
-    command: mongod --port ${DB__PORT:-27017}
+    command: mongod --port ${DB__PORT}
     volumes:
       - database:/data/db
     healthcheck:
-      test: ["CMD", "mongosh", "--quiet", "--port", "${DB__PORT:-27017}", "--eval", "db.adminCommand('ping')"]
+      test: ["CMD", "mongosh", "--quiet", "--port", "${DB__PORT}", "--eval", "db.adminCommand('ping')"]
       interval: 5s
       timeout: 5s
       retries: 5
     networks:
       database:
         aliases:
-          - ${DB__HOST:-mongodb}
+          - ${DB__HOST}
 {% endif %}
 {%- if database == 'postgres' %}
   postgres:
@@ -72,6 +72,7 @@ services:
       POSTGRES_USER: ${DB__USER}
       POSTGRES_PASSWORD: ${DB__PASSWORD}
       POSTGRES_DB: ${DB__DB_NAME}
+      PGPORT: ${DB__PORT}
     volumes:
       - database:/var/lib/postgresql/data
     healthcheck:
@@ -82,7 +83,7 @@ services:
     networks:
       database:
         aliases:
-          - ${DB__HOST:-postgres}
+          - ${DB__HOST}
 
   migrator:
     build: {{ part_dir }}
@@ -114,9 +115,9 @@ services:
     image: redis:7-alpine
     profiles: [redis, external]
     restart: unless-stopped
-    command: ["redis-server", "--appendonly", "yes"]
+    command: ["redis-server", "--port", "${REDIS__PORT}", "--appendonly", "yes"]
     healthcheck:
-      test: ["CMD", "redis-cli", "ping"]
+      test: ["CMD", "redis-cli", "-p", "${REDIS__PORT}", "ping"]
       interval: 5s
       timeout: 5s
       retries: 5
@@ -125,7 +126,7 @@ services:
     networks:
       redis:
         aliases:
-          - ${REDIS__HOST:-redis}
+          - ${REDIS__HOST}
 {% endif %}
 {%- if database != 'none' or use_redis %}
 volumes: