Add docker builder option to improve build tooling (#10935)

This adds the ability to pass in a docker builder option to docker. This makes building multi-arch images super simple by using our k8s infrastructure.

It also makes building multi-arch images very fast since they can be built in parallel and on native hardware.

DCO Sign off

I agree to the DCO for all the commits in this PR.

Co-authored-by: Alejandro Pedraza <alejandro.pedraza@gmail.com>

bin/_docker.sh

@@ -23,6 +23,8 @@ export DOCKER_TARGET=${DOCKER_TARGET:-$(os)}
 # When set together with DOCKER_TARGET=multi-arch, it will push the multi-arch images to the registry
 export DOCKER_PUSH=${DOCKER_PUSH:-}
 
+export DOCKER_BUILDER=${DOCKER_BUILDER:-}
+
 # Default supported docker image architectures
 export SUPPORTED_ARCHS=${SUPPORTED_ARCHS:-linux/amd64,linux/arm64,linux/arm/v7}
 
@@ -82,6 +84,13 @@ See https://github.com/docker/buildx/issues/59 for more details'
       fi
     fi
 
+    # Allow for specifying docker builder engine
+    # This is a great way to use k8s to build docker images on native hardware instead of emulated
+    # See https://docs.docker.com/build/drivers/kubernetes/ for an example
+    if [ "$DOCKER_BUILDER" ]; then
+      output_params+=" --builder=$DOCKER_BUILDER"
+    fi
+
     log_debug "  :; docker buildx $rootdir $cache_params $output_params -t $repo:$tag -f $file $*"
     # shellcheck disable=SC2086
     docker buildx build "$rootdir" $cache_params \