tests/e2e: speedup: run make build-helper-images in parallel mode

Makefile

@@ -128,9 +128,13 @@ build-docker-%:
 	DOCKER_BUILDKIT=1 docker build . -t k3d:$(K3D_IMAGE_TAG)-$* --target $*
 
 # build helper images
-build-helper-images:
+build-helper-images: build-proxy-image build-tools-image
+
+build-proxy-image:
 	@echo "Building docker image rancher/k3d-proxy:$(K3D_IMAGE_TAG)"
-	DOCKER_BUILDKIT=1 docker build proxy/ -f proxy/Dockerfile -t rancher/k3d-proxy:$(K3D_IMAGE_TAG)
+	DOCKER_BUILDKIT=1 docker build --no-cache proxy/ -f proxy/Dockerfile -t rancher/k3d-proxy:$(K3D_IMAGE_TAG)
+
+build-tools-image:
 	@echo "Building docker image rancher/k3d-tools:$(K3D_IMAGE_TAG)"
 	DOCKER_BUILDKIT=1 docker build --no-cache tools/ -f tools/Dockerfile -t rancher/k3d-tools:$(K3D_IMAGE_TAG) --build-arg GIT_TAG=$(GIT_TAG)
 

tests/dind.sh

@@ -49,7 +49,7 @@ done
 
 # build helper container images
 if [ -z "$E2E_HELPER_IMAGE_TAG" ]; then
-  docker exec --workdir /src "$k3de2e" make build-helper-images
+  docker exec --workdir /src "$k3de2e" make -j2 build-helper-images
   # execute tests
   echo "Start time outside runner: $(date)"
   docker exec "$k3de2e" /src/tests/runner.sh