Have Istio optional

[eguzki]

What

This is a preparation work for on-boarding EnvoyGateway on following up PRs. It is, essentially, moving Istio from being the required GatewayAPI provider to optional gateway provider. Among other things, being optional means that when Istio is not installed in the cluster, the kuadrant operator does not die. Additionally, make room for on-boarding other GatewayAPI providers.

• [X] Make Istio EnvoyFilter controller optional. When istio envoy filter CRD or GatewayAPI CRD is not installed, the controller does not start.
• [X] Make Istio Wasmplugin controller optional. When istio WasmPlugin CRD or GatewayAPI CRD is not installed, the controller does not start.
• [X] Make kuadrant controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [X] Make ratelimitpolicy controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [X] Make authpolicy controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [X] Make dnspolicy controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [X] Make tlspolicy controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [X] Make target status controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [X] Make ratelimit policy enforcedstatus controller optional. When GatewayAPI CRD is not installed, the controller does not start.
• [x] Make Istio optional. When istio is not installed, the kuadrant operator still runs.
• [X] At golang level, helper functions working with Istio APIs in github.com/kuadrant/kuadrant-operator/pkg/istio package. Controllers should be the only one importing that package.
• [ ] Add check or die test to find one of the supported GatewayAPI providers.
• [x] (Integration) Tests refactor.

Golang package	Required environment	Makefile env setup target	Makefile test run target
github.com/kuadrant/kuadrant-operator/tests/bare_k8s	no gateway provider, no GatewayAPI CRDs. Just Kuadrant API and Kuadrant dependencies.	make local-k8s-env-setup	make test-bare-k8s-integration
github.com/kuadrant/kuadrant-operator/tests/gatewayapi	no gateway provider. GatewayAPI CRDs, Kuadrant API and Kuadrant dependencies.	make local-gatewayapi-env-setup	make test-gatewayapi-env-integration
github.com/kuadrant/kuadrant-operator/controllers	at least one gatewayapi provider. It can be any: istio, envoygateway, ...	make local-env-setup GATEWAYAPI_PROVIDER=[ISTIO|SAIL] (Default Istio)	make test-integration
github.com/kuadrant/kuadrant-operator/tests/istio	GatewayAPI CRDs, Istio, Kuadrant API and Kuadrant dependencies.	make local-env-setup GATEWAYAPI_PROVIDER=ISTIO	make test-istio-env-integration

Defined behavior

GatewayAPI CRDs	Istio	Kuadrant CR status
NO	NO	Not reconciled
YES	NO	Error: GatewayAPI provider not found
YES	YES	OK

Verification Steps

• Run cluster without gatewayAPI and without Istio installed

make kind-delete-cluster \
&& make kind-create-cluster \
&& make deploy-metrics-server \
&& make namespace \
&& make install-cert-manager \
&& make deploy-dependencies \
&& kubectl -n kuadrant-system wait --timeout=300s --for=condition=Available deployments --all \
&& make install

• Run the operator

make run 

The operator should report in logs that multiple controller were disabled as required APIs not found.

2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.kuadrant	Kuadrant controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.ratelimitpolicy	Ratelimitpolicy controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.authpolicy	AuthPolicy controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.dnspolicy	DNSPolicy controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.tlspolicy	TLSPolicy controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.ratelimitpolicy.envoyfilter	Istio EnvoyFilter controller disabled. Istio was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.kuadrant.gateway	GatewayKuadrant controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.ratelimitpolicy.wasmplugin	Istio WasmPlugin controller disabled. Istio was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.targetstatus	TargetStatus controller disabled. GatewayAPI was not found
2024-05-17T11:27:03+02:00	INFO	kuadrant-operator.ratelimitpolicy.status	RateLimitPolicyEnforcedStatus controller disabled. GatewayAPI was not found