Configuration

A global configuration is required to exists as a package settings.default_settings. Per-installation/environment configuration is possible. A file with suffix cfg and name set in environment variable ZSL_SETTINGS is needed.

Environment variables

• ZSL_SETTINGS Location of the per-installation configuration file (with *.cfg suffix).

Required fields

• TASKS The task router will search for task according to the task configuration. The object under this variable is an instance of zsl.router.task.TaskConfiguration. The users register the packages holding task classes under their urls. See the example app and the following example for more.

  If we have a FooApiTask in module myapp.tasks.api.v1.foo_api_task, then we register it under url /api/v1 in so that we use:

  TASKS = TaskConfiguration()\
    .create_namespace('api/v1')\
      .add_packages(['myapp.tasks.api.v1'])\
      .get_configuration()
  

  Notice that all the tasks in the modules in the package myapp.tasks.api.v1.foo_api_task will be routed under /api/v1 url. If one needs a more detailed routing, then add_routes method is much more convenient.

• RESOURCE_PACKAGES List of packages with resources. The resource router will search any resource in these packages with given order.

• DATABASE_URI Database URL for SQLAlchemy’s crate_engine.

• DATABASE_ENGINE_PROPS A dictionary of optional properties for the DB connection.

• SERVICE_INJECTION List of services initialized and bind to the injecor after start.:

  SERVICE_INJECTION = ({
      'list':  ['AccountService', 'BuildService']
      'package': 'app.services'
  })
  

• REDIS Redis configuration.

Optional fields

• RELOAD Reload tasks on every call. Especially usable when debugging.

• DEBUG Set the debug mode - True or False.

• LOGGING Logging settings are specified in LOGGING variable as a python dictionary. ZSL uses python logging as the logging infrastructure and the configuration is done accordingly.

  The concrete options are specified in Python Logging library in the part called dictionary configuration, just check the logging.config module documentation for more. An example is here.:

  LOGGING = {
      'version': 1,
      'formatters': {
          'default': {
              'format': '%(levelname)s %(name)s %(asctime)-15s %(message)s'
          }
      },
      'handlers': {
          'console': {
              'class': 'logging.StreamHandler',
              'formatter': 'default'
          },
      },
      'loggers': {
          'storage': {
              'handlers': ['console'],
              'level': 'DEBUG',
              'propagate': True,
          }
      },
      'root': {
          'handlers': ['console'],
          'level': 'DEBUG',
          'propagate': True,
      }
  }
  

  Because of using Flask one has to provide import_name parameter to the zsl.application.service_application.ServiceApplication object constructor. This import_name is also the name of the root logger used in the application. Thus it is convenient to choose as the root package name of the project.

• EXTERNAL_LIBRARIES Add external libraries to path. This option will be deprecated use a correct virtualenv environment instead.:

  EXTERNAL_LIBRARIES = {
      'vendor_path': './vendor'
      'libs': ['my_lib_dir1', 'my_lib_dir2']
  }
  

• CORS The configuration containing the default CORS/crossdomain settings. Check zsl.application.modules.web.cors.CORSConfiguration. The available options are:

  • origin,

  • allow_headers,

  • expose_headers,

  • max_age.

  Check CORS explanation on Wikipedia.