Cleanup build dates in Skaffold (gardener#7956)

Signed-off-by: Brian Topping <brian.topping@sap.com>

Makefile

@@ -24,6 +24,7 @@ EXTENSION_PROVIDER_LOCAL_IMAGE_REPOSITORY  := $(REGISTRY)/extensions/provider-lo
 PUSH_LATEST_TAG                            := false
 VERSION                                    := $(shell cat VERSION)
 EFFECTIVE_VERSION                          := $(VERSION)-$(shell git rev-parse HEAD)
+BUILD_DATE                                 := $(shell date '+%Y-%m-%dT%H:%M:%S%z' | sed 's/\([0-9][0-9]\)$$/:\1/g')
 REPO_ROOT                                  := $(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))
 GARDENER_LOCAL_KUBECONFIG                  := $(REPO_ROOT)/example/gardener-local/kind/local/kubeconfig
 GARDENER_LOCAL2_KUBECONFIG                 := $(REPO_ROOT)/example/gardener-local/kind/local2/kubeconfig
@@ -360,10 +361,11 @@ kind-operator-down: $(KIND)
 export SKAFFOLD_BUILD_CONCURRENCY = 0
 gardener%up gardener%dev gardener%debug gardenlet%up gardenlet%dev gardenlet%debug operator-up operator-dev operator-debug: export SKAFFOLD_DEFAULT_REPO = localhost:5001
 gardener%up gardener%dev gardener%debug gardenlet%up gardenlet%dev gardenlet%debug operator-up operator-dev operator-debug: export SKAFFOLD_PUSH = true
+gardener%up gardener%dev gardener%debug gardenlet%up gardenlet%dev gardenlet%debug operator-up operator-dev operator-debug: export SOURCE_DATE_EPOCH = $(shell date -d $(BUILD_DATE) +%s)
 # use static label for skaffold to prevent rolling all gardener components on every `skaffold` invocation
 gardener%up gardener%dev gardener%debug gardener%down gardenlet%up gardenlet%dev gardenlet%debug gardenlet%down: export SKAFFOLD_LABEL = skaffold.dev/run-id=gardener-local
 # set ldflags for skaffold
-gardener%up gardener%dev gardener%debug gardenlet%up gardenlet%dev gardenlet%debug operator-up operator-dev operator-debug: export LD_FLAGS = $(shell $(REPO_ROOT)/hack/get-build-ld-flags.sh)
+gardener%up gardener%dev gardener%debug gardenlet%up gardenlet%dev gardenlet%debug operator-up operator-dev operator-debug: export LD_FLAGS = $(shell $(REPO_ROOT)/hack/get-build-ld-flags.sh k8s.io/component-base $(REPO_ROOT)/VERSION Gardener $(BUILD_DATE))
 # skaffold dev and debug clean up deployed modules by default, disable this
 gardener%dev gardener%debug gardenlet%dev gardenlet%debug operator-dev operator-debug: export SKAFFOLD_CLEANUP = false
 # skaffold dev triggers new builds and deployments immediately on file changes by default,

hack/get-build-ld-flags.sh

@@ -19,6 +19,7 @@ set -e
 PACKAGE_PATH="${1:-k8s.io/component-base}"
 VERSION_PATH="${2:-$(dirname $0)/../VERSION}"
 PROGRAM_NAME="${3:-Gardener}"
+BUILD_DATE="${4:-$(date '+%Y-%m-%dT%H:%M:%S%z' | sed 's/\([0-9][0-9]\)$/:\1/g')}"
 VERSION_VERSIONFILE="$(cat "$VERSION_PATH")"
 VERSION="${EFFECTIVE_VERSION:-$VERSION_VERSIONFILE}"
 
@@ -46,5 +47,5 @@ echo "-X $PACKAGE_PATH/version.gitMajor=$MAJOR_VERSION
       -X $PACKAGE_PATH/version.gitVersion=$VERSION
       -X $PACKAGE_PATH/version.gitTreeState=$TREE_STATE
       -X $PACKAGE_PATH/version.gitCommit=$(git rev-parse --verify HEAD)
-      -X $PACKAGE_PATH/version.buildDate=$(date '+%Y-%m-%dT%H:%M:%S%z' | sed 's/\([0-9][0-9]\)$/:\1/g')
+      -X $PACKAGE_PATH/version.buildDate=$BUILD_DATE
       -X $PACKAGE_PATH/version/verflag.programName=$PROGRAM_NAME"