I’m trying to deploy a FastAPI application on Render and I’m encountering an issue. When I attempt to deploy the application, I receive the following errors:

==> Exited with status 1
==> Common ways to troubleshoot your deploy: https://docs.render.com/troubleshooting-deploys
Skipping virtualenv creation, as specified in config file.
...
POSTGRES_USER
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
POSTGRES_PASSWORD
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
POSTGRES_PORT
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
POSTGRES_DB
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
POSTGRES_HOST
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
POSTGRES_HOST_DOCKER
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
DATABASE_URL
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
ACCESS_TOKEN_SECRET_KEY
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
ACCESS_TOKEN_EXPIRE_MINUTES
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
REFRESH_TOKEN_SECRET_KEY
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
REFRESH_TOKEN_EXPIRE_DAYS
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
ALGORITHM
  Field required [type=missing, input_value={}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.8/v/missing
...
Skipping virtualenv creation, as specified in config file.

.env

# PostgreSQL
POSTGRES_USER=postgres
POSTGRES_PASSWORD=55555
POSTGRES_PORT=5432
POSTGRES_DB=db_name
POSTGRES_HOST=localhost # delete later

# PostgreSQL for Docker
POSTGRES_HOST_DOCKER=db
DATABASE_URL=postgresql+asyncpg://{POSTGRES_USER}:{POSTGRES_PASSWORD}@{POSTGRES_HOST_DOCKER}:{POSTGRES_PORT}/{POSTGRES_DB}

# JWT
ACCESS_TOKEN_SECRET_KEY=some access token
ACCESS_TOKEN_EXPIRE_MINUTES=60
REFRESH_TOKEN_SECRET_KEY=some refresh token
REFRESH_TOKEN_EXPIRE_DAYS=30
ALGORITHM=HS256

Config

class Settings(BaseSettings):
    TITLE: str = "App name"
    VERSION: str = "0.0.1"
    TIMEZONE: str = "UTC"
    DESCRIPTION: str | None = None
    DEBUG: bool = False

    DOCS_URL: str = "/docs"
    OPENAPI_URL: str = "/openapi.json"
    REDOC_URL: str = "/redoc"

    POSTGRES_USER: str
    POSTGRES_PASSWORD: str
    POSTGRES_PORT: int
    POSTGRES_DB: str
    POSTGRES_HOST: str
    POSTGRES_HOST_DOCKER: str
    DATABASE_URL: str

    ACCESS_TOKEN_SECRET_KEY: str
    ACCESS_TOKEN_EXPIRE_MINUTES: int
    REFRESH_TOKEN_SECRET_KEY: str
    REFRESH_TOKEN_EXPIRE_DAYS: int
    ALGORITHM: str

    IS_ALLOWED_CREDENTIALS: bool = True
    ALLOWED_ORIGINS: list[str] = [
        "http://localhost:3000",
        "http://0.0.0.0:3000",
        "http://127.0.0.1:3000",
        "http://127.0.0.1:3001",
        "http://localhost:5173",
        "http://0.0.0.0:5173",
        "http://127.0.0.1:5173",
        "http://127.0.0.1:5174",
        "https://render-url-here.onrender.com" 
    ]
    ALLOWED_METHODS: list[str] = ["*"]
    ALLOWED_HEADERS: list[str] = ["*"]

    model_config = SettingsConfigDict(env_file=".env", extra="allow")

docker-compose.yml

services:
  db:
    image: postgres:14
    restart: always
    environment:
      POSTGRES_USER: ${POSTGRES_USER}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
      POSTGRES_DB: ${POSTGRES_DB}
    volumes:
      - postgres_data:/var/lib/postgresql/data

  migrate:
    build: .
    command: poetry run alembic upgrade head
    volumes:
      - .:/app
    depends_on:
      - db
    environment:
      DATABASE_URL: postgresql+asyncpg://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST_DOCKER}:${POSTGRES_PORT}/${POSTGRES_DB}

  web:
    build: .
    command: poetry run uvicorn app.main:app --host 0.0.0.0 --port 8000
    volumes:
      - .:/app
    ports:
      - "8000:8000"
    depends_on:
      - db
      - migrate
    environment:
      ALGORITHM: ${ALGORITHM}
      ACCESS_TOKEN_SECRET_KEY: ${ACCESS_TOKEN_SECRET_KEY}
      ACCESS_TOKEN_EXPIRE_MINUTES: ${ACCESS_TOKEN_EXPIRE_MINUTES}
      REFRESH_TOKEN_SECRET_KEY: ${REFRESH_TOKEN_SECRET_KEY}
      REFRESH_TOKEN_EXPIRE_DAYS: ${REFRESH_TOKEN_EXPIRE_DAYS}

volumes:
  postgres_data:

I tried deploying without the .env file and manually specifying the environment variables, but then I encountered a different problem with connecting to the database, which I didn’t have when deploying on my local machine. So, I decided to try it with the .env file.