Make every published host port overridable

.env.example

@@ -1,6 +1,14 @@
 # Copy to .env to override docker-compose defaults for local development.
 # None of these are required — sane dev defaults are baked into docker-compose.yml.
 
+# Host ports. Only the host side of each mapping -- inside the compose network
+# the services always reach each other on the standard ports.
+POSTGRES_HOST_PORT=5432
+REDIS_HOST_PORT=6379
+CORE_API_HOST_PORT=8000
+INGESTION_HOST_PORT=8080
+FRONTEND_HOST_PORT=5173
+
 POSTGRES_USER=pipelineops
 POSTGRES_PASSWORD=pipelineops
 POSTGRES_DB=pipelineops

README.md

@@ -132,15 +132,27 @@ Go ingestion service, and the frontend, running migrations and seeding an
 `admin` / `admin` superuser automatically (dev-only — see `.env.example`
 to disable that).
 
-| Service | URL |
-|---|---|
-| Frontend dashboard | http://localhost:5173 |
-| Core API | http://localhost:8000/api/ |
-| Django admin | http://localhost:8000/admin/ |
-| Ingestion service | http://localhost:8080 |
-
-> If a port above is already taken on your machine, override it, e.g.
-> `POSTGRES_HOST_PORT=5434 FRONTEND_HOST_PORT=5175 docker compose up --build`.
+| Service | URL | Host port override |
+|---|---|---|
+| Frontend dashboard | http://localhost:5173 | `FRONTEND_HOST_PORT` |
+| Core API | http://localhost:8000/api/ | `CORE_API_HOST_PORT` |
+| Django admin | http://localhost:8000/admin/ | `CORE_API_HOST_PORT` |
+| Ingestion service | http://localhost:8080 | `INGESTION_HOST_PORT` |
+| Postgres | localhost:5432 | `POSTGRES_HOST_PORT` |
+| Redis | localhost:6379 | `REDIS_HOST_PORT` |
+
+> Every host port above is overridable, which matters because 5432 and 6379 in
+> particular are usually already taken by something. Set them inline or in
+> `.env`:
+>
+> ```bash
+> POSTGRES_HOST_PORT=5434 REDIS_HOST_PORT=6380 CORE_API_HOST_PORT=8800 \
+>   INGESTION_HOST_PORT=8880 FRONTEND_HOST_PORT=5175 docker compose up --build
+> ```
+>
+> Only the host side moves — inside the compose network the services still
+> reach each other on the standard ports, and the frontend is built against
+> whatever `CORE_API_HOST_PORT` is, so the browser follows automatically.
 
 ### Try it end to end
 

docker-compose.yml

@@ -20,7 +20,7 @@ services:
   redis:
     image: redis:7-alpine
     ports:
-      - "6379:6379"
+      - "${REDIS_HOST_PORT:-6379}:6379"
     healthcheck:
       test: ["CMD", "redis-cli", "ping"]
       interval: 5s
@@ -45,7 +45,7 @@ services:
       DJANGO_SUPERUSER_PASSWORD: ${DJANGO_SUPERUSER_PASSWORD:-admin}
       DJANGO_SUPERUSER_EMAIL: ${DJANGO_SUPERUSER_EMAIL:-admin@pipelineops.local}
     ports:
-      - "8000:8000"
+      - "${CORE_API_HOST_PORT:-8000}:8000"
     depends_on:
       postgres:
         condition: service_healthy
@@ -93,7 +93,7 @@ services:
       REDIS_URL: redis://redis:6379/0
       GIN_MODE: release
     ports:
-      - "8080:8080"
+      - "${INGESTION_HOST_PORT:-8080}:8080"
     depends_on:
       core-api:
         condition: service_healthy
@@ -109,7 +109,7 @@ services:
     build:
       context: ./frontend
       args:
-        VITE_API_BASE_URL: http://localhost:8000
+        VITE_API_BASE_URL: http://localhost:${CORE_API_HOST_PORT:-8000}
     ports:
       - "${FRONTEND_HOST_PORT:-5173}:80"
     depends_on: