Harden database startup for Portainer

backend/app/config.py

@@ -1,5 +1,6 @@
 from functools import lru_cache
 
+from sqlalchemy.engine import URL
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
@@ -7,13 +8,33 @@ class Settings(BaseSettings):
     model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")
 
     app_name: str = "Plast Track MVP"
-    database_url: str = "postgresql+psycopg://plasttrack:plasttrack@database:5432/plasttrack"
+    database_url: str | None = None
+    postgres_host: str = "database"
+    postgres_port: int = 5432
+    postgres_db: str = "plasttrack"
+    postgres_user: str = "plasttrack"
+    postgres_password: str = "plasttrack"
     mqtt_host: str = "mqtt"
     mqtt_port: int = 1883
     mqtt_topic: str = "plasttrack/machines/+/events"
     mqtt_client_id: str = "plast-track-backend"
     frontend_origin: str = "http://localhost:5173"
     downtime_check_interval_sec: int = 5
+    database_startup_retries: int = 30
+    database_startup_retry_delay_sec: float = 2.0
+
+    @property
+    def sqlalchemy_database_url(self) -> str:
+        if self.database_url:
+            return self.database_url
+        return URL.create(
+            "postgresql+psycopg",
+            username=self.postgres_user,
+            password=self.postgres_password,
+            host=self.postgres_host,
+            port=self.postgres_port,
+            database=self.postgres_db,
+        ).render_as_string(hide_password=False)
 
 
 @lru_cache