assert.NoError(t, err)
	fakeIPSetDeps.AssertExpectations(t)
}

// for tests that call `runtime.GC()` - we have no control over when the GC is actually scheduled,
// and it is flake-prone to check for closure after calling it, this retries for a bit to make
// sure the netns is closed eventually.
func assertNSClosed(t *testing.T, closed *atomic.Bool) {
	for i := 0; i < 5; i++ {
		if closed.Load() {

This can be reading from Kubernetes and writing other objects back, writing to proxies over XDS, etc.

Unfortunately, writing controllers is very error prone, even for seemingly simple cases.
To work around this, Istio has a variety of abstractions meant to make writing controllers easier.

## Clients

endif
ifeq ($(PULL_POLICY),)
  $(error "PULL_POLICY cannot be empty")
endif

PROW_ARTIFACTS_BASE ?= https://gcsweb.istio.io/gcs/istio-prow

include tools/proto/proto.mk

.PHONY: default
default: init build test

.PHONY: init
# Downloads envoy, based on the SHA defined in the base pilot Dockerfile
init: $(TARGET_OUT)/istio_is_init init-ztunnel-rs
	@mkdir -p ${TARGET_OUT}/logs
	@mkdir -p ${TARGET_OUT}/release

ifeq ($(BUILD_WITH_CONTAINER),1)
# create phony targets for the top-level items in the repo
PHONYS := $(shell ls | grep -v Makefile)
.PHONY: $(PHONYS)
$(PHONYS):
	@$(MAKE_DOCKER) $@
endif

# istioctl-install builds then installs istioctl into $GOPATH/BIN
# Used for debugging istioctl during dev work
.PHONY: istioctl-install
istioctl-install: istioctl-install-container

help: ## Show this help
	@egrep -h '^[a-zA-Z_\.-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort  | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'

export

RUN = ./common/scripts/run.sh

MAKE_DOCKER = $(RUN) make --no-print-directory -e -f Makefile.core.mk

%:
	@$(MAKE_DOCKER) $@

default:
	@$(MAKE_DOCKER)

shell:
	@$(RUN) /bin/bash

.PHONY: default shell

else

# If we are not in build container, we need a workaround to get environment properly set
# Write to file, then include
$(shell mkdir -p out)

This caching depends on declaring all inputs to the given generator as part of the cache key. This is extremely error-prone, as there is nothing preventing generators from consuming inputs that are *not* part of the key. When this happens, different clients will non-deterministically get incorrect configuration. This type of bug has historically resulted in CVEs.