Make backend port configurable via .env and update related configurations

.env.example

@@ -3,6 +3,7 @@ APP_ENV=development
 APP_DEBUG=false
 APP_NAME=LTA DataMall Bus Backend
 APP_VERSION=0.1.0
+APP_PORT=8000
 DATAMALL_BASE_URL=https://datamall2.mytransport.sg/ltaodataservice
 REQUEST_TIMEOUT_SECONDS=10
 MAX_CONNECTIONS=200

Dockerfile

@@ -19,4 +19,4 @@ COPY openapi.json ./openapi.json
 
 EXPOSE 8000
 
-CMD ["uv", "run", "gunicorn", "app.main:app", "-k", "uvicorn.workers.UvicornWorker", "-w", "4", "-b", "0.0.0.0:8000", "--access-logfile", "-", "--error-logfile", "-"]
+CMD ["sh", "-c", "uv run gunicorn app.main:app -k uvicorn.workers.UvicornWorker -w 4 -b 0.0.0.0:${APP_PORT:-8000} --access-logfile - --error-logfile -"]

Makefile

@@ -1,6 +1,9 @@
 APP_MODULE=app.main:app
 HOST=0.0.0.0
-PORT=8000
+
+-include .env
+
+APP_PORT ?= 8000
 
 PYTHON_RUN=uv run
 
@@ -51,12 +54,12 @@ sync:
 	uv sync
 
 run:
-	$(PYTHON_RUN) uvicorn $(APP_MODULE) --host $(HOST) --port $(PORT) --reload
+	$(PYTHON_RUN) uvicorn $(APP_MODULE) --host $(HOST) --port $(APP_PORT) --reload
 
 dev: run
 
 prod:
-	$(PYTHON_RUN) gunicorn $(APP_MODULE) -k uvicorn.workers.UvicornWorker -w 4 -b $(HOST):$(PORT) --access-logfile - --error-logfile -
+	$(PYTHON_RUN) gunicorn $(APP_MODULE) -k uvicorn.workers.UvicornWorker -w 4 -b $(HOST):$(APP_PORT) --access-logfile - --error-logfile -
 
 compile:
 	$(PYTHON_RUN) python -m compileall app
@@ -70,7 +73,7 @@ image-build: check-engine
 	$(CONTAINER_ENGINE) build -t lta-datamall-bus-backend:latest .
 
 image-run: check-engine
-	$(CONTAINER_ENGINE) run -d --name lta-datamall-bus-backend --env-file .env -p 8000:8000 lta-datamall-bus-backend:latest
+	$(CONTAINER_ENGINE) run -d --name lta-datamall-bus-backend --env-file .env -p $(APP_PORT):$(APP_PORT) lta-datamall-bus-backend:latest
 
 image-stop: check-engine
 	-$(CONTAINER_ENGINE) stop lta-datamall-bus-backend

README.md

@@ -8,6 +8,7 @@ FastAPI backend platform for LTA DataMall Bus Transport APIs, dockerized for pro
 - Valkey caching layer with graceful fallback when cache is unavailable
 - Scalable runtime with Gunicorn + Uvicorn workers
 - API key loaded from `.env` (`DATAMALL_API_KEY`)
+- Backend port configurable via `.env` (`APP_PORT`)
 - Bus Transport endpoints exposed under `/api/v1`
 - Container health endpoints: `/healthz`, `/readyz`
 
@@ -34,7 +35,7 @@ uv sync
 4. Start the app:
 
 ```bash
-uv run uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload
+uv run uvicorn app.main:app --host 0.0.0.0 --port ${APP_PORT:-8000} --reload
 ```
 
 ## Docker Run
@@ -49,7 +50,7 @@ docker compose up --build -d
 3. Check health:
 
 ```bash
-curl http://localhost:8000/healthz
+curl http://localhost:${APP_PORT:-8000}/healthz
 ```
 
 The compose stack includes a Valkey service for caching.
@@ -62,6 +63,7 @@ Set in `.env`:
 - `VALKEY_URL=redis://valkey:6379/0`
 - `VALKEY_CONNECT_TIMEOUT_SECONDS=1`
 - `VALKEY_DEFAULT_TTL_SECONDS=120`
+- `APP_PORT=8000`
 
 Current cache behavior:
 

app/core/config.py

@@ -11,6 +11,7 @@ class Settings(BaseSettings):
     app_env: str = "development"
     app_debug: bool = False
     app_version: str = "0.1.0"
+    app_port: int = Field(8000, ge=1, le=65535)
 
     datamall_base_url: str = "https://datamall2.mytransport.sg/ltaodataservice"
     datamall_api_key: str = Field(..., description="LTA DataMall AccountKey")

docker-compose.yml

@@ -16,9 +16,9 @@ services:
     depends_on:
       - valkey
     ports:
-      - "8000:8000"
+      - "${APP_PORT:-8000}:${APP_PORT:-8000}"
     healthcheck:
-      test: ["CMD", "python", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:8000/healthz', timeout=3)"]
+      test: ["CMD", "python", "-c", "import os, urllib.request; urllib.request.urlopen(f'http://localhost:{os.getenv(\"APP_PORT\", \"8000\")}/healthz', timeout=3)"]
       interval: 30s
       timeout: 5s
       retries: 3

tests/core/test_config.py

@@ -0,0 +1,13 @@
+from app.core.config import Settings
+
+
+def test_settings_default_backend_port_is_8000():
+    settings = Settings(datamall_api_key="test-account-key")
+
+    assert settings.app_port == 8000
+
+
+def test_settings_reads_backend_port_from_env_value():
+    settings = Settings(datamall_api_key="test-account-key", app_port=9010)
+
+    assert settings.app_port == 9010