What is the primary function of the Docker API?

The Docker API's primary function is to interact programmatically with the Docker daemon. This API allows developers to communicate with the Docker daemon, which is the core component responsible for managing Docker containers, images, networks, and volumes. By using the Docker API, users can automate container management tasks, such as starting and stopping containers, building images, and querying the status of containers.

This interaction is crucial for building tools and applications that need to manage Docker environments without manual intervention. The API provides a rich set of endpoints that cover all aspects of container management, enabling a high level of integration with various development processes and workflows.

Other options, while related to Docker, do not reflect the primary function of the API itself. For example, creating new Docker containers is one of the many actions that can be performed through the API, but it does not capture the full scope of its capabilities. Similarly, monitoring system performance and managing user permissions involve different facets of system administration and security, which can utilize Docker APIs but do not define their core purpose.