Where are Docker secrets primarily used?

Docker secrets are primarily used in Docker Swarm mode to manage sensitive data such as passwords, API keys, and other confidential information without exposing them in the application code or configuration files. When Docker is in Swarm mode, it provides a way to securely store and manage secrets that can be distributed to services that need them without risking unauthorized access.

Secrets in Docker Swarm are encrypted both in transit and at rest, ensuring that they remain confidential. They are only accessible to the services that require them, and Docker handles the secure delivery to the containers at runtime. This design enhances security and simplifies how sensitive data is managed across distributed services.

While Docker containers can utilize secrets, it's specifically within the context of Swarm mode that Docker provides the built-in functionality for managing these secrets securely. Other options don't capture this specific context as effectively, as local development environments may not implement the same level of security measures for secrets, and Docker networking configurations do not inherently involve managing sensitive information.