Modify README/usage to address the current situation (#177)

Currently, our image repository (ghcr.io) is private. So users should
build and load images themselves.
This PR modifies The usage part in README to add that information.

Fixes: #175

Author: k8s-ci-robot

Makefile

@@ -331,11 +331,13 @@ build.cluster: $(KTF) # builds a KIND cluster which can be used for testing and
 .PHONY: load.image
 load.image: build.image
 	kind load docker-image $(BLIXT_CONTROLPLANE_IMAGE):$(TAG) --name $(KIND_CLUSTER) && \
-		kubectl -n blixt-system rollout restart deployment blixt-controlplane
+		kubectl -n blixt-system get deployment blixt-controlplane >/dev/null 2>&1 && \
+		kubectl -n blixt-system rollout restart deployment blixt-controlplane || true
 
 .PHONY: load.all.images
 load.all.images: build.all.images
 	kind load docker-image $(BLIXT_CONTROLPLANE_IMAGE):$(TAG) --name $(KIND_CLUSTER) && \
 	kind load docker-image $(BLIXT_DATAPLANE_IMAGE):$(TAG) --name $(KIND_CLUSTER) && \
 	kind load docker-image $(BLIXT_UDP_SERVER_IMAGE):$(TAG) --name $(KIND_CLUSTER) && \
-		kubectl -n blixt-system rollout restart deployment blixt-controlplane
+		kubectl -n blixt-system get deployment blixt-controlplane >/dev/null 2>&1 && \
+		kubectl -n blixt-system rollout restart deployment blixt-controlplane || true

README.md

@@ -81,13 +81,28 @@ to have _you_ join us in iterating on it and helping us build it together!
 > (KIND)][kind] clusters. You can generate a new development cluster for
 > testing with `make build.cluster`.
 
-Deploy [Gateway API][gwapi] [CRDs][crds]:
+> **Note**: Currently our container images are under migration from a private repository.
+> At this moment, you should build and load images yourself.
+
+1. Deploy [Gateway API][gwapi] [CRDs][crds]:
 
 ```console
 kubectl apply -k https://github.com/kubernetes-sigs/gateway-api/config/crd/experimental?ref=v0.8.1
 ```
 
-Deploy:
+2. Build Blixt images:
+
+```console
+make build.all.images TAG=latest
+```
+
+3. Load images into your Kind cluster:
+
+```console
+make load.all.images TAG=latest
+```
+
+4. Deploy Blixt:
 
 ```console
 kubectl apply -k config/default