Motivation

With the new Container concept and the ContainerFactory fixture introduced in #8781, we now want an easy and re-usable way to configure containers. For instance, to test extensions, I always want to create a fresh localstack pro container with certain default configurations. The code doing the configuration should ideally be re-usable, have high-level concepts of the localstack container (such as "mount the localstack volume directory", "set gateway listen correctly"), while allowing fine-grained configuration of containers.

In #8994 I introduced a concept that is inspired by the Functional Options Pattern from go. I evolved this into a basic set of configurators that are typical for localstack.

This gives a very neat way of configuring the container together with the container factory, where you can see exactly what configurations are being added to the container:

  container: Container = container_factory(
      configurators=[
          ContainerConfigurators.random_container_name,
          ContainerConfigurators.random_gateway_port,
          ContainerConfigurators.debug,
          ContainerConfigurators.mount_docker_socket,
          ContainerConfigurators.mount_localstack_volume("/tmp/localstack"),
      ]
  )

Furthermore, I wanted a way to stream container logs when running container tests, so I added a fixture that can be used as follows:

def test(container_factory, stream_container_logs)
    container: Container = container_factory(...)
    with container.start() as running_container:
        stream_container_logs(container)

This creates a new background thread that will stream the logs of the container into a logger called container.<container-name>.

Changes

• Add ContainerConfigurator concept
• Make Container aware of these configurators
• Add a default set of container configurators
• Refactor the configure_container method used by the CLI to use these configurators
• Add way to determine the gateway URL from a Container
• Add some tests and a fixture to stream logs
• Sneaked in a few changes to use VolumeMappings.add instead of append so we can maybe get rid of one of the functions

TODO

• Requires add utility to find contiguous port range #9051