How do you configure Uvicorn's log config file for custom logging formats?

# logging.json - custom log config in dictConfig format
{
  "version": 1,
  "disable_existing_loggers": false,
  "formatters": {
    "default": {
      "()": "uvicorn.logging.DefaultFormatter",
      "fmt": "%(levelprefix)s %(asctime)s %(message)s",
      "use_colors": false
    },
    "access": {
      "()": "uvicorn.logging.AccessFormatter",
      "fmt": '%(levelprefix)s %(asctime)s %(client_addr)s - "%(request_line)s" %(status_code)s',
      "use_colors": false
    }
  },
  "handlers": {
    "default": {
      "formatter": "default",
      "class": "logging.StreamHandler",
      "stream": "ext://sys.stderr"
    },
    "access": {
      "formatter": "access",
      "class": "logging.StreamHandler",
      "stream": "ext://sys.stdout"
    }
  },
  "loggers": {
    "uvicorn": {"handlers": ["default"], "level": "INFO", "propagate": false},
    "uvicorn.error": {"level": "INFO"},
    "uvicorn.access": {"handlers": ["access"], "level": "INFO", "propagate": false}
  }
}

# Use the custom log config:
uvicorn main:app --log-config logging.json

# Or YAML format (requires PyYAML - included in uvicorn[standard]):
uvicorn main:app --log-config logging.yaml

# Programmatically:
import logging.config, json
with open("logging.json") as f:
    log_config = json.load(f)
uvicorn.run("main:app", log_config=log_config)