How limit cpu of docker buildx build？

[darklinght]

When using docker buildx build to create an image, it can cause the computer's CPU to max out. Are there any ways to limit CPU usage during the build process?

[mg1986jp]

A few options depending on your driver:

If you're using the docker-container driver (the default for docker buildx create), the builder itself runs as a container. You can limit its CPU after it's created:

docker update --cpus 4 buildx_buildkit_<builder-name>0

You can also set max-parallelism in a buildkitd.toml to control how many build steps run concurrently:

[worker.oci]
  max-parallelism = 4

Then create the builder with:

docker buildx create --config ./buildkitd.toml

If you're using the default docker driver, the build runs inside the Docker daemon process itself and there's no clean way to cap its CPU from buildx. In that case you'd probably want to switch to docker-container driver so you can control it.