build: Makefile support for DOCKER_IMAGE_SUFFIX, CI_BUILD, and KIND_LOAD

DOCKER_IMAGE_SUFFIX, if defined, will be added to the end of th docker
image name, before the tag. For example:

$ DOCKER_IMAGE_SUFFIX=-ci make docker-cilium-image

will build `quay.io/cilium/cilium-ci:latest`

CI_BUILD, if defined, will define DOCKER_IMAGE_SUFFIX as "-ci", and
DOCKER_IMAGE_TAG as the git HEAD SHA, which will then replace the default
"latest" tag in the example above. This helps build local images with the
same image reference that real CI builds would use.

KIND_LOAD, if defined, will load the build image with "kind load" one
second after the build completes. The one second delay was required as
without it "kind load" sometimes reported that it can't find the image
that was just built.

Signed-off-by: Jarno Rajahalme <jarno@isovalent.com>

Makefile.defs

@@ -41,6 +41,11 @@ ifeq ($(DOCKER_DEV_ACCOUNT),)
     DOCKER_DEV_ACCOUNT=cilium
 endif
 
+ifneq ($(CI_BUILD),)
+    DOCKER_IMAGE_SUFFIX=-ci
+    DOCKER_IMAGE_TAG=$(shell git rev-parse HEAD)
+endif
+
 # Set DOCKER_IMAGE_TAG with "latest" by default
 ifeq ($(DOCKER_IMAGE_TAG),)
     DOCKER_IMAGE_TAG=latest

Makefile.docker

@@ -96,12 +96,17 @@ endif
 		--build-arg CILIUM_SHA=$(firstword $(GIT_VERSION)) \
 		--build-arg OPERATOR_VARIANT=$(IMAGE_NAME) \
 		--target $(5) \
-		-t $(IMAGE_REPOSITORY)/$(IMAGE_NAME)$${UNSTRIPPED}:$(4) .
-ifeq ($(findstring --push,$(DOCKER_FLAGS)),)
-	@echo 'Define "DOCKER_FLAGS=--push" to push the build results.'
+		-t $(IMAGE_REPOSITORY)/$(IMAGE_NAME)$${UNSTRIPPED}$(DOCKER_IMAGE_SUFFIX):$(4) .
+ifneq ($(KIND_LOAD),)
+	sleep 1
+	kind load docker-image $(IMAGE_REPOSITORY)/$(IMAGE_NAME)$${UNSTRIPPED}$(DOCKER_IMAGE_SUFFIX):$(4)
 else
+    ifeq ($(findstring --push,$(DOCKER_FLAGS)),)
+	@echo 'Define "DOCKER_FLAGS=--push" to push the build results.'
+    else
 	$(CONTAINER_ENGINE) buildx imagetools inspect $(IMAGE_REPOSITORY)/$(IMAGE_NAME):$(4)
 	@echo '^^^ Images pushed, multi-arch manifest should be above. ^^^'
+    endif
 endif
 
 $(1)-unstripped: NOSTRIP=1