Add helm charts for easy deployments

[feiskyer]

Add helm charts for easy deployments

[MartinForReal]

We've got kustomize template in config dir. Do we need to publish all-in-one yaml in release artifacts?

[feiskyer]

It's better have a helm chart instead of kustomize, so that the lifecyles could be managed easier (e.g. customize parameters and upgrade in the future).

[MartinForReal]

I'm not quite sure but in following Makefile the versions and parameters can be updated in a script automatically.

kube-egress-gateway/Makefile

Lines 112 to 117 in 8ec6a4f

	$(KUSTOMIZE) edit set image controller=$(IMAGE_REGISTRY)/$(CONTROLLER_IMG):$(IMAGE_TAG) && \
	$(KUSTOMIZE) edit set image daemon=$(IMAGE_REGISTRY)/${DAEMON_IMG}:$(IMAGE_TAG) && \
	$(KUSTOMIZE) edit set image cnimanager=$(IMAGE_REGISTRY)/${CNIMANAGER_IMG}:$(IMAGE_TAG) && \
	$(KUSTOMIZE) edit set image cni=$(IMAGE_REGISTRY)/${CNI_IMG}:$(IMAGE_TAG) && \
	$(KUSTOMIZE) edit set image cni-ipam=$(IMAGE_REGISTRY)/${CNI_IPAM_IMG}:$(IMAGE_TAG)
	$(KUSTOMIZE) build config/default | kubectl apply -f -

[MartinForReal]

However, it is not a big deal, if the reviewer has checked whether configs and parameters are the same before pr is merged.

[feiskyer]

Though the steps in Makefile would work, it's not as easy as helm chart.

[feiskyer]

Helm chart has been added in #148.