How can a resource limit be set on a Docker container's CPU?

Setting a resource limit on a Docker container's CPU is essential for controlling how much of the host's CPU resources a container can use. This is crucial in multi-container environments to ensure that one container does not starve others of required resources, maintaining overall system stability.

Using the --cpus option with the docker run command allows you to specify the number of CPU cores that the container can utilize, expressed as a decimal value. For instance, if you set --cpus=2, the container is allowed to use up to two CPU cores. This approach directly enforces the CPU limitation at the time the container is started, providing a straightforward way to manage resource allocation dynamically.

The other methods mentioned do not provide a mechanism for setting CPU limits. Modifying the Dockerfile directly cannot enforce runtime resource constraints, and the --cpu-limit command is not a valid option in Docker's command set. Additionally, while some graphical interfaces may provide options for setting resources, they typically rely on underlying command-line configurations and do not have separate commands to specify limits directly.