How can you connect a container to an existing Docker network?

To connect a container to an existing Docker network, the appropriate command is "docker network connect [network_name] [container_id]". This command is specifically designed to add an already running container to an existing network.

When a container is connected to a Docker network, it can communicate with other containers on that network using their container names or IP addresses. This connectivity is crucial for distributed applications where different components need to communicate with each other efficiently.

The syntax of the command indicates that you specify the network name first, followed by the container ID. This clearly links the container to the specified network while maintaining the container’s existing configurations and settings. Unlike other methods that may suggest outdated or incorrect practices, this command adheres to Docker's current networking features and best practices.

Using this command allows you to easily integrate different services or applications running in different containers, fostering a flexible architecture for development and deployment.